diff --git a/documentation/README.md b/documentation/README.md
index 8664415..1fbedde 100644
--- a/documentation/README.md
+++ b/documentation/README.md
@@ -18,6 +18,12 @@ Welcome to the JobOps documentation. This folder contains comprehensive guides f
   - PDF generation and regeneration
   - Post-application tracking overview
 
+- **[Ghostwriter](./ghostwriter.md)** - Context-aware per-job chat assistant
+  - One persistent conversation per job
+  - Streaming responses, stop, and regenerate
+  - Markdown rendering and drawer UX behavior
+  - Writing style settings impact
+
 - **[Post-Application Tracking](./post-application-tracking.md)** - Email-to-job matching
   - How the Smart Router AI works
   - Gmail integration setup
@@ -58,6 +64,7 @@ JobOps uses specialized extractors to gather jobs from different sources:
 documentation/
 ├── self-hosting.md          # Deployment guide
 ├── orchestrator.md          # Core workflow documentation
+├── ghostwriter.md           # Ghostwriter feature documentation
 ├── post-application-tracking.md  # Email tracking feature
 └── extractors/              # Job source extractors
     ├── README.md
diff --git a/documentation/ghostwriter.md b/documentation/ghostwriter.md
new file mode 100644
index 0000000..1ba8b9c
--- /dev/null
+++ b/documentation/ghostwriter.md
@@ -0,0 +1,60 @@
+# Ghostwriter
+
+Ghostwriter is the per-job AI chat assistant in JobOps. It is optional to use and is designed for drafting application content with job-specific context already loaded.
+
+## What Ghostwriter is for
+
+Ghostwriter is not a generic chat box. For each job, it uses:
+
+- The current job description and job metadata
+- A reduced snapshot of your resume/profile
+- Your global Ghostwriter writing style settings
+
+This makes it useful for:
+
+- Drafting role-specific answers
+- Cover letter and outreach drafts
+- Interview prep talking points tied to the current JD
+- Rephrasing content to match your preferred style
+
+## Where it appears
+
+- Available from job details in `discovered` and `ready` flows
+- Opens as a right-side drawer
+- One persistent conversation per job
+
+## Writing style settings impact
+
+Ghostwriter settings are global and affect new generations:
+
+- `Tone`: adds a tone instruction in the Ghostwriter system prompt
+- `Formality`: adds a formality instruction
+- `Constraints`: appended as explicit writing constraints
+- `Do-not-use terms`: appended as language to avoid
+
+Defaults:
+
+- Tone: `professional`
+- Formality: `medium`
+- Constraints: empty
+- Do-not-use terms: empty
+
+## Context + safety model
+
+Ghostwriter context is assembled server-side with size limits and sanitization:
+
+- Job snapshot is truncated to fit prompt budget
+- Profile snapshot includes only relevant slices (summary, skills, projects, experience)
+- System prompt enforces read-only assistant behavior
+- Logging stores metadata only (not raw full prompt/response dumps)
+
+## API surface (current)
+
+Primary per-job endpoints:
+
+- `GET /api/jobs/:id/chat/messages`
+- `POST /api/jobs/:id/chat/messages` (supports streaming)
+- `POST /api/jobs/:id/chat/runs/:runId/cancel`
+- `POST /api/jobs/:id/chat/messages/:assistantMessageId/regenerate` (supports streaming)
+
+Compatibility endpoints for thread resources remain present, but UI behavior is one conversation per job.
diff --git a/documentation/orchestrator.md b/documentation/orchestrator.md
index a73fec3..0619a99 100644
--- a/documentation/orchestrator.md
+++ b/documentation/orchestrator.md
@@ -30,10 +30,23 @@ There are two main ways a job becomes Ready:
 Once a job is `ready`, the Ready panel is the "shipping lane":
 
 - View/download the PDF.
+- Open Ghostwriter for context-aware drafting tied to the current job.
 - Open the job listing.
 - Mark Applied (moves to `applied`).
 - Optional: edit tailoring, edit the JD, or regenerate the PDF.
 
+## Ghostwriter (per-job context chat)
+
+Ghostwriter is always on and is available in both `discovered` and `ready` job views.
+
+- It uses the current job context, profile context, and your global writing style settings.
+- Conversation state is persistent per job.
+- Responses stream in real time and can be cancelled.
+- Regenerate is available for the last assistant response.
+- Messages render as Markdown.
+
+For full details and API surface, see [Ghostwriter](./ghostwriter.md).
+
 ## Generating PDFs (first time)
 
 The PDF is generated from:
diff --git a/orchestrator/src/client/api/client.ts b/orchestrator/src/client/api/client.ts
index 35b3b77..049042e 100644
--- a/orchestrator/src/client/api/client.ts
+++ b/orchestrator/src/client/api/client.ts
@@ -15,6 +15,9 @@ import type {
   BulkPostApplicationActionResponse,
   DemoInfoResponse,
   Job,
+  JobChatMessage,
+  JobChatStreamEvent,
+  JobChatThread,
   JobListItem,
   JobOutcome,
   JobSource,
@@ -390,6 +393,264 @@ export async function updateJob(
   });
 }
 
+async function streamSseEvents(
+  endpoint: string,
+  input: Record<string, unknown>,
+  handlers: {
+    onEvent: (event: JobChatStreamEvent) => void;
+    signal?: AbortSignal;
+  },
+): Promise<void> {
+  const headers: Record<string, string> = {
+    "Content-Type": "application/json",
+  };
+  if (cachedBasicAuthCredentials) {
+    headers.Authorization = encodeBasicAuth(cachedBasicAuthCredentials);
+  }
+
+  const response = await fetch(`${API_BASE}${endpoint}`, {
+    method: "POST",
+    headers,
+    body: JSON.stringify(input),
+    signal: handlers.signal,
+  });
+
+  if (!response.ok) {
+    let errorMessage = `Stream request failed with status ${response.status}`;
+    try {
+      const payload = await response.json();
+      const parsed = normalizeApiResponse(payload);
+      if ("ok" in parsed && !parsed.ok) {
+        errorMessage = parsed.error.message || errorMessage;
+      }
+    } catch {
+      // ignore parse errors; keep status-based message
+    }
+    throw new ApiClientError(errorMessage, {
+      status: response.status,
+    });
+  }
+
+  if (!response.body) {
+    throw new ApiClientError("Streaming not supported by this browser");
+  }
+
+  const decoder = new TextDecoder();
+  const reader = response.body.getReader();
+  let buffer = "";
+
+  while (true) {
+    const { done, value } = await reader.read();
+    if (done) break;
+    buffer += decoder.decode(value, { stream: true });
+
+    let separatorIndex = buffer.indexOf("\n\n");
+    while (separatorIndex !== -1) {
+      const frame = buffer.slice(0, separatorIndex);
+      buffer = buffer.slice(separatorIndex + 2);
+      const dataLines = frame
+        .split("\n")
+        .filter((line) => line.startsWith("data:"))
+        .map((line) => line.slice(5).trim())
+        .filter(Boolean);
+
+      for (const line of dataLines) {
+        try {
+          handlers.onEvent(JSON.parse(line) as JobChatStreamEvent);
+        } catch {
+          // Ignore malformed events to keep stream resilient
+        }
+      }
+      separatorIndex = buffer.indexOf("\n\n");
+    }
+  }
+}
+
+export async function listJobChatThreads(jobId: string): Promise<{
+  threads: JobChatThread[];
+}> {
+  return fetchApi<{ threads: JobChatThread[] }>(`/jobs/${jobId}/chat/threads`);
+}
+
+export async function listJobGhostwriterMessages(
+  jobId: string,
+  options?: { limit?: number; offset?: number },
+): Promise<{ messages: JobChatMessage[] }> {
+  const params = new URLSearchParams();
+  if (typeof options?.limit === "number") {
+    params.set("limit", String(options.limit));
+  }
+  if (typeof options?.offset === "number") {
+    params.set("offset", String(options.offset));
+  }
+  const query = params.toString();
+  return fetchApi<{ messages: JobChatMessage[] }>(
+    `/jobs/${jobId}/chat/messages${query ? `?${query}` : ""}`,
+  );
+}
+
+export async function createJobChatThread(
+  jobId: string,
+  input?: { title?: string | null },
+): Promise<{ thread: JobChatThread }> {
+  return fetchApi<{ thread: JobChatThread }>(`/jobs/${jobId}/chat/threads`, {
+    method: "POST",
+    body: JSON.stringify({
+      title: input?.title ?? null,
+    }),
+  });
+}
+
+export async function listJobChatMessages(
+  jobId: string,
+  threadId: string,
+  options?: { limit?: number; offset?: number },
+): Promise<{ messages: JobChatMessage[] }> {
+  const params = new URLSearchParams();
+  if (typeof options?.limit === "number") {
+    params.set("limit", String(options.limit));
+  }
+  if (typeof options?.offset === "number") {
+    params.set("offset", String(options.offset));
+  }
+  const query = params.toString();
+  return fetchApi<{ messages: JobChatMessage[] }>(
+    `/jobs/${jobId}/chat/threads/${threadId}/messages${query ? `?${query}` : ""}`,
+  );
+}
+
+export async function sendJobChatMessage(
+  jobId: string,
+  threadId: string,
+  input: { content: string },
+): Promise<{
+  userMessage: JobChatMessage;
+  assistantMessage: JobChatMessage | null;
+  runId: string;
+}> {
+  return fetchApi<{
+    userMessage: JobChatMessage;
+    assistantMessage: JobChatMessage | null;
+    runId: string;
+  }>(`/jobs/${jobId}/chat/threads/${threadId}/messages`, {
+    method: "POST",
+    body: JSON.stringify(input),
+  });
+}
+
+export async function streamJobChatMessage(
+  jobId: string,
+  threadId: string,
+  input: { content: string; signal?: AbortSignal },
+  handlers: {
+    onEvent: (event: JobChatStreamEvent) => void;
+  },
+): Promise<void> {
+  return streamSseEvents(
+    `/jobs/${jobId}/chat/threads/${threadId}/messages`,
+    { content: input.content, stream: true },
+    {
+      onEvent: handlers.onEvent,
+      signal: input.signal,
+    },
+  );
+}
+
+export async function streamJobGhostwriterMessage(
+  jobId: string,
+  input: { content: string; signal?: AbortSignal },
+  handlers: {
+    onEvent: (event: JobChatStreamEvent) => void;
+  },
+): Promise<void> {
+  return streamSseEvents(
+    `/jobs/${jobId}/chat/messages`,
+    { content: input.content, stream: true },
+    {
+      onEvent: handlers.onEvent,
+      signal: input.signal,
+    },
+  );
+}
+
+export async function cancelJobChatRun(
+  jobId: string,
+  threadId: string,
+  runId: string,
+): Promise<{ cancelled: boolean; alreadyFinished: boolean }> {
+  return fetchApi<{ cancelled: boolean; alreadyFinished: boolean }>(
+    `/jobs/${jobId}/chat/threads/${threadId}/runs/${runId}/cancel`,
+    {
+      method: "POST",
+      body: JSON.stringify({}),
+    },
+  );
+}
+
+export async function cancelJobGhostwriterRun(
+  jobId: string,
+  runId: string,
+): Promise<{ cancelled: boolean; alreadyFinished: boolean }> {
+  return fetchApi<{ cancelled: boolean; alreadyFinished: boolean }>(
+    `/jobs/${jobId}/chat/runs/${runId}/cancel`,
+    {
+      method: "POST",
+      body: JSON.stringify({}),
+    },
+  );
+}
+
+export async function regenerateJobChatMessage(
+  jobId: string,
+  threadId: string,
+  assistantMessageId: string,
+): Promise<{ runId: string; assistantMessage: JobChatMessage | null }> {
+  return fetchApi<{ runId: string; assistantMessage: JobChatMessage | null }>(
+    `/jobs/${jobId}/chat/threads/${threadId}/messages/${assistantMessageId}/regenerate`,
+    {
+      method: "POST",
+      body: JSON.stringify({}),
+    },
+  );
+}
+
+export async function streamRegenerateJobChatMessage(
+  jobId: string,
+  threadId: string,
+  assistantMessageId: string,
+  input: { signal?: AbortSignal },
+  handlers: {
+    onEvent: (event: JobChatStreamEvent) => void;
+  },
+): Promise<void> {
+  return streamSseEvents(
+    `/jobs/${jobId}/chat/threads/${threadId}/messages/${assistantMessageId}/regenerate`,
+    { stream: true },
+    {
+      onEvent: handlers.onEvent,
+      signal: input.signal,
+    },
+  );
+}
+
+export async function streamRegenerateJobGhostwriterMessage(
+  jobId: string,
+  assistantMessageId: string,
+  input: { signal?: AbortSignal },
+  handlers: {
+    onEvent: (event: JobChatStreamEvent) => void;
+  },
+): Promise<void> {
+  return streamSseEvents(
+    `/jobs/${jobId}/chat/messages/${assistantMessageId}/regenerate`,
+    { stream: true },
+    {
+      onEvent: handlers.onEvent,
+      signal: input.signal,
+    },
+  );
+}
+
 export async function processJob(
   id: string,
   options?: { force?: boolean },
diff --git a/orchestrator/src/client/components/ReadyPanel.tsx b/orchestrator/src/client/components/ReadyPanel.tsx
index 79b488b..d0066ce 100644
--- a/orchestrator/src/client/components/ReadyPanel.tsx
+++ b/orchestrator/src/client/components/ReadyPanel.tsx
@@ -50,6 +50,7 @@ import { useProfile } from "../hooks/useProfile";
 import { useRescoreJob } from "../hooks/useRescoreJob";
 import { FitAssessment, JobHeader, TailoredSummary } from ".";
 import { TailorMode } from "./discovered-panel/TailorMode";
+import { GhostwriterDrawer } from "./ghostwriter/GhostwriterDrawer";
 import { JobDetailsEditDrawer } from "./JobDetailsEditDrawer";
 import { KbdHint } from "./KbdHint";
 
@@ -297,18 +298,10 @@ export const ReadyPanel: React.FC<ReadyPanelProps> = ({
       ───────────────────────────────────────────────────────────────────── */}
       <div className="pb-4 border-b border-border/40">
         <div className="grid gap-2 sm:grid-cols-2">
-          {/* Show PDF - to verify quickly without download */}
-          <Button
-            asChild
-            variant="outline"
-            className="h-9 w-full gap-1 px-2 text-xs"
-          >
-            <a href={pdfHref} target="_blank" rel="noopener noreferrer">
-              <FileText className="h-3.5 w-3.5 shrink-0" />
-              <span className="truncate">View PDF</span>
-              <KbdHint shortcut="p" className="ml-auto" />
-            </a>
-          </Button>
+          <GhostwriterDrawer
+            job={job}
+            triggerClassName="h-9 w-full justify-center gap-1 px-2 text-xs"
+          />
 
           {/* Download PDF - primary artifact action */}
           <Button
@@ -448,6 +441,15 @@ export const ReadyPanel: React.FC<ReadyPanelProps> = ({
             <DropdownMenuSeparator />
 
             {/* Utility actions */}
+            <DropdownMenuItem
+              onSelect={() =>
+                window.open(pdfHref, "_blank", "noopener,noreferrer")
+              }
+            >
+              <FileText className="mr-2 h-4 w-4" />
+              View PDF
+            </DropdownMenuItem>
+
             <DropdownMenuItem onSelect={handleCopyInfo}>
               <Copy className="mr-2 h-4 w-4" />
               Copy job info
diff --git a/orchestrator/src/client/components/ghostwriter/Composer.tsx b/orchestrator/src/client/components/ghostwriter/Composer.tsx
new file mode 100644
index 0000000..9f1ecaa
--- /dev/null
+++ b/orchestrator/src/client/components/ghostwriter/Composer.tsx
@@ -0,0 +1,90 @@
+import { getMetaShortcutLabel, isMetaKeyPressed } from "@client/lib/meta-key";
+import { RefreshCcw, Send, Square } from "lucide-react";
+import type React from "react";
+import { useState } from "react";
+import { Button } from "@/components/ui/button";
+import { Textarea } from "@/components/ui/textarea";
+
+type ComposerProps = {
+  disabled?: boolean;
+  isStreaming: boolean;
+  canRegenerate: boolean;
+  onRegenerate: () => Promise<void>;
+  onStop: () => Promise<void>;
+  onSend: (content: string) => Promise<void>;
+};
+
+export const Composer: React.FC<ComposerProps> = ({
+  disabled,
+  isStreaming,
+  canRegenerate,
+  onRegenerate,
+  onStop,
+  onSend,
+}) => {
+  const [value, setValue] = useState("");
+
+  const submit = async () => {
+    const content = value.trim();
+    if (!content || disabled) return;
+    setValue("");
+    await onSend(content);
+  };
+
+  return (
+    <div className="space-y-2">
+      <Textarea
+        placeholder="Ask anything about this job..."
+        value={value}
+        onChange={(event) => setValue(event.target.value)}
+        disabled={disabled}
+        onKeyDown={(event) => {
+          if (isMetaKeyPressed(event) && event.key === "Enter") {
+            event.preventDefault();
+            void submit();
+          }
+        }}
+        className="min-h-[84px]"
+      />
+      <div className="flex items-center justify-between">
+        <div className="text-[10px] text-muted-foreground">
+          {getMetaShortcutLabel("Enter")} to send
+        </div>
+        <div className="flex items-center gap-1">
+          {isStreaming ? (
+            <Button
+              size="icon"
+              variant="outline"
+              onClick={() => void onStop()}
+              aria-label="Stop generating"
+              title="Stop generating"
+            >
+              <Square className="h-3.5 w-3.5" />
+            </Button>
+          ) : (
+            <Button
+              size="icon"
+              variant="outline"
+              onClick={() => void onRegenerate()}
+              disabled={disabled || !canRegenerate}
+              aria-label="Regenerate response"
+              title="Regenerate response"
+            >
+              <RefreshCcw className="h-3.5 w-3.5" />
+            </Button>
+          )}
+
+          <Button
+            size="icon"
+            onClick={() => void submit()}
+            disabled={disabled || !value.trim()}
+            aria-label="Send message"
+            title="Send message"
+          >
+            <Send className="h-3.5 w-3.5" />
+          </Button>
+        </div>
+      </div>
+    </div>
+  );
+};
diff --git a/orchestrator/src/client/components/ghostwriter/GhostwriterDrawer.tsx b/orchestrator/src/client/components/ghostwriter/GhostwriterDrawer.tsx
new file mode 100644
index 0000000..efb6b37
--- /dev/null
+++ b/orchestrator/src/client/components/ghostwriter/GhostwriterDrawer.tsx
@@ -0,0 +1,63 @@
+import type { Job } from "@shared/types";
+import { PanelRightOpen } from "lucide-react";
+import type React from "react";
+import { useState } from "react";
+import { Button } from "@/components/ui/button";
+import {
+  Sheet,
+  SheetContent,
+  SheetDescription,
+  SheetHeader,
+  SheetTitle,
+  SheetTrigger,
+} from "@/components/ui/sheet";
+import { cn } from "@/lib/utils";
+import { GhostwriterPanel } from "./GhostwriterPanel";
+
+type GhostwriterDrawerProps = {
+  job: Job | null;
+  triggerClassName?: string;
+};
+
+export const GhostwriterDrawer: React.FC<GhostwriterDrawerProps> = ({
+  job,
+  triggerClassName,
+}) => {
+  const [open, setOpen] = useState(false);
+
+  return (
+    <Sheet open={open} onOpenChange={setOpen}>
+      <SheetTrigger asChild>
+        <Button
+          size="sm"
+          variant="outline"
+          className={cn("h-8 gap-1.5 text-xs", triggerClassName)}
+          disabled={!job}
+        >
+          <PanelRightOpen className="h-3.5 w-3.5" />
+          Ghostwriter
+        </Button>
+      </SheetTrigger>
+
+      <SheetContent
+        side="right"
+        className="flex w-full flex-col p-0 sm:max-w-none lg:w-[50vw] xl:w-[40vw] 2xl:w-[30vw]"
+      >
+        <div className="border-b border-border/50 p-4">
+          <SheetHeader>
+            <SheetTitle>Ghostwriter</SheetTitle>
+            <SheetDescription>
+              {job && `${job.title} at ${job.employer}.`}
+            </SheetDescription>
+          </SheetHeader>
+        </div>
+
+        {job && (
+          <div className="flex min-h-0 flex-1 p-4 pt-0">
+            <GhostwriterPanel job={job} />
+          </div>
+        )}
+      </SheetContent>
+    </Sheet>
+  );
+};
diff --git a/orchestrator/src/client/components/ghostwriter/GhostwriterPanel.tsx b/orchestrator/src/client/components/ghostwriter/GhostwriterPanel.tsx
new file mode 100644
index 0000000..244c545
--- /dev/null
+++ b/orchestrator/src/client/components/ghostwriter/GhostwriterPanel.tsx
@@ -0,0 +1,283 @@
+import type { Job, JobChatMessage, JobChatStreamEvent } from "@shared/types";
+import type React from "react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
+import { toast } from "sonner";
+import * as api from "../../api";
+import { Composer } from "./Composer";
+import { MessageList } from "./MessageList";
+
+type GhostwriterPanelProps = {
+  job: Job;
+};
+
+export const GhostwriterPanel: React.FC<GhostwriterPanelProps> = ({ job }) => {
+  const [messages, setMessages] = useState<JobChatMessage[]>([]);
+  const [isLoading, setIsLoading] = useState(true);
+  const [isStreaming, setIsStreaming] = useState(false);
+  const [streamingMessageId, setStreamingMessageId] = useState<string | null>(
+    null,
+  );
+  const [activeRunId, setActiveRunId] = useState<string | null>(null);
+
+  const messageListRef = useRef<HTMLDivElement | null>(null);
+  const streamAbortRef = useRef<AbortController | null>(null);
+  const messageCount = messages.length;
+
+  useEffect(() => {
+    if (messageCount === 0) return;
+    const container = messageListRef.current;
+    if (!container) return;
+    const distanceToBottom =
+      container.scrollHeight - container.scrollTop - container.clientHeight;
+    if (distanceToBottom < 120 || isStreaming) {
+      container.scrollTop = container.scrollHeight;
+    }
+  }, [messageCount, isStreaming]);
+
+  const loadMessages = useCallback(async () => {
+    const data = await api.listJobGhostwriterMessages(job.id, {
+      limit: 300,
+    });
+    setMessages(data.messages);
+  }, [job.id]);
+
+  const load = useCallback(async () => {
+    setIsLoading(true);
+    try {
+      await loadMessages();
+    } catch (error) {
+      const message =
+        error instanceof Error ? error.message : "Failed to load Ghostwriter";
+      toast.error(message);
+    } finally {
+      setIsLoading(false);
+    }
+  }, [loadMessages]);
+
+  useEffect(() => {
+    void load();
+    return () => {
+      streamAbortRef.current?.abort();
+      streamAbortRef.current = null;
+    };
+  }, [load]);
+
+  const onStreamEvent = useCallback(
+    (event: JobChatStreamEvent) => {
+      if (event.type === "ready") {
+        setActiveRunId(event.runId);
+        setStreamingMessageId(event.messageId);
+        setMessages((current) => {
+          if (current.some((message) => message.id === event.messageId)) {
+            return current;
+          }
+          return [
+            ...current,
+            {
+              id: event.messageId,
+              threadId: event.threadId,
+              jobId: job.id,
+              role: "assistant",
+              content: "",
+              status: "partial",
+              tokensIn: null,
+              tokensOut: null,
+              version: 1,
+              replacesMessageId: null,
+              createdAt: new Date().toISOString(),
+              updatedAt: new Date().toISOString(),
+            },
+          ];
+        });
+        return;
+      }
+
+      if (event.type === "delta") {
+        setMessages((current) =>
+          current.map((message) =>
+            message.id === event.messageId
+              ? {
+                  ...message,
+                  content: `${message.content}${event.delta}`,
+                  status: "partial",
+                  updatedAt: new Date().toISOString(),
+                }
+              : message,
+          ),
+        );
+        return;
+      }
+
+      if (event.type === "completed" || event.type === "cancelled") {
+        setMessages((current) => {
+          const next = current.filter(
+            (message) => message.id !== event.message.id,
+          );
+          return [...next, event.message].sort((a, b) =>
+            a.createdAt.localeCompare(b.createdAt),
+          );
+        });
+        setStreamingMessageId(null);
+        setActiveRunId(null);
+        setIsStreaming(false);
+        return;
+      }
+
+      if (event.type === "error") {
+        toast.error(event.message);
+        setStreamingMessageId(null);
+        setActiveRunId(null);
+        setIsStreaming(false);
+      }
+    },
+    [job.id],
+  );
+
+  const sendMessage = useCallback(
+    async (content: string) => {
+      if (isStreaming) return;
+
+      const optimisticUser: JobChatMessage = {
+        id: `tmp-user-${Date.now()}`,
+        threadId: messages[messages.length - 1]?.threadId || "pending-thread",
+        jobId: job.id,
+        role: "user",
+        content,
+        status: "complete",
+        tokensIn: null,
+        tokensOut: null,
+        version: 1,
+        replacesMessageId: null,
+        createdAt: new Date().toISOString(),
+        updatedAt: new Date().toISOString(),
+      };
+
+      setMessages((current) => [...current, optimisticUser]);
+      setIsStreaming(true);
+
+      const controller = new AbortController();
+      streamAbortRef.current = controller;
+
+      try {
+        await api.streamJobGhostwriterMessage(
+          job.id,
+          { content, signal: controller.signal },
+          { onEvent: onStreamEvent },
+        );
+
+        await loadMessages();
+      } catch (error) {
+        if (error instanceof Error && error.name === "AbortError") {
+          return;
+        }
+
+        const message =
+          error instanceof Error ? error.message : "Failed to send message";
+        toast.error(message);
+      } finally {
+        streamAbortRef.current = null;
+        setIsStreaming(false);
+      }
+    },
+    [isStreaming, job.id, loadMessages, messages, onStreamEvent],
+  );
+
+  const stopStreaming = useCallback(async () => {
+    streamAbortRef.current?.abort();
+    streamAbortRef.current = null;
+    setIsStreaming(false);
+    setStreamingMessageId(null);
+    const runId = activeRunId;
+    setActiveRunId(null);
+
+    if (!runId) {
+      return;
+    }
+
+    try {
+      await api.cancelJobGhostwriterRun(job.id, runId);
+      await loadMessages();
+    } catch (error) {
+      const message =
+        error instanceof Error ? error.message : "Failed to stop run";
+      toast.error(message);
+    }
+  }, [activeRunId, job.id, loadMessages]);
+
+  const canRegenerate = useMemo(() => {
+    if (isStreaming || messages.length === 0) return false;
+    const last = messages[messages.length - 1];
+    return last.role === "assistant";
+  }, [isStreaming, messages]);
+
+  const regenerate = useCallback(async () => {
+    if (isStreaming || messages.length === 0) return;
+    const last = messages[messages.length - 1];
+    if (last.role !== "assistant") return;
+
+    setIsStreaming(true);
+    const controller = new AbortController();
+    streamAbortRef.current = controller;
+
+    try {
+      await api.streamRegenerateJobGhostwriterMessage(
+        job.id,
+        last.id,
+        { signal: controller.signal },
+        { onEvent: onStreamEvent },
+      );
+      await loadMessages();
+    } catch (error) {
+      if (error instanceof Error && error.name === "AbortError") {
+        return;
+      }
+      const message =
+        error instanceof Error
+          ? error.message
+          : "Failed to regenerate response";
+      toast.error(message);
+    } finally {
+      streamAbortRef.current = null;
+      setIsStreaming(false);
+    }
+  }, [isStreaming, job.id, loadMessages, messages, onStreamEvent]);
+
+  return (
+    <div className="flex h-full min-h-0 flex-1 flex-col">
+      <div
+        ref={messageListRef}
+        className="min-h-0 flex-1 overflow-y-auto border-b border-border/50 pb-3 pr-1"
+      >
+        {messages.length === 0 && !isLoading ? (
+          <div className="flex h-full min-h-[260px] justify-center px-3 flex-col text-left">
+            <h4 className="font-medium">
+              {job.title} at {job.employer}
+            </h4>
+            <p className="mt-2 text-sm leading-relaxed text-muted-foreground">
+              Ghostwriter already has this job description, your resume and your
+              writing style preferences. Ask for tailored response drafts, or
+              concise role-fit talking points.
+            </p>
+          </div>
+        ) : (
+          <MessageList
+            messages={messages}
+            isStreaming={isStreaming}
+            streamingMessageId={streamingMessageId}
+          />
+        )}
+      </div>
+
+      <div className="mt-4">
+        <Composer
+          disabled={isLoading || isStreaming}
+          isStreaming={isStreaming}
+          canRegenerate={canRegenerate}
+          onRegenerate={regenerate}
+          onStop={stopStreaming}
+          onSend={sendMessage}
+        />
+      </div>
+    </div>
+  );
+};
diff --git a/orchestrator/src/client/components/ghostwriter/MessageList.tsx b/orchestrator/src/client/components/ghostwriter/MessageList.tsx
new file mode 100644
index 0000000..297d4de
--- /dev/null
+++ b/orchestrator/src/client/components/ghostwriter/MessageList.tsx
@@ -0,0 +1,60 @@
+import type { JobChatMessage } from "@shared/types";
+import type React from "react";
+import ReactMarkdown from "react-markdown";
+import remarkGfm from "remark-gfm";
+import { StreamingMessage } from "./StreamingMessage";
+
+type MessageListProps = {
+  messages: JobChatMessage[];
+  isStreaming: boolean;
+  streamingMessageId: string | null;
+};
+
+export const MessageList: React.FC<MessageListProps> = ({
+  messages,
+  isStreaming,
+  streamingMessageId,
+}) => {
+  return (
+    <div className="space-y-3">
+      {messages.length > 0 &&
+        messages.map((message) => {
+          const isUser = message.role === "user";
+          const isActiveStreaming =
+            isStreaming &&
+            message.role === "assistant" &&
+            streamingMessageId === message.id;
+
+          return (
+            <div
+              key={message.id}
+              className={`rounded-lg border p-3 ${
+                isUser
+                  ? "border-primary/30 bg-primary/5"
+                  : "border-border/60 bg-background"
+              }`}
+            >
+              <div className="mb-1 text-[10px] uppercase tracking-wide text-muted-foreground">
+                {isUser
+                  ? "You"
+                  : `Ghostwriter${message.version > 1 ? ` v${message.version}` : ""}`}
+              </div>
+              {isActiveStreaming ? (
+                <StreamingMessage content={message.content} />
+              ) : message.role === "assistant" ? (
+                <div className="text-sm leading-relaxed text-foreground [&_a]:text-primary [&_a]:underline [&_blockquote]:border-l [&_blockquote]:border-border [&_blockquote]:pl-3 [&_code]:rounded [&_code]:bg-muted/40 [&_code]:px-1 [&_h1]:mt-4 [&_h1]:text-base [&_h1]:font-semibold [&_h2]:mt-4 [&_h2]:text-sm [&_h2]:font-semibold [&_h3]:mt-3 [&_h3]:text-sm [&_h3]:font-semibold [&_li]:my-1 [&_ol]:my-2 [&_ol]:list-decimal [&_ol]:pl-5 [&_p]:my-2 [&_pre]:my-3 [&_pre]:overflow-x-auto [&_pre]:rounded [&_pre]:bg-muted/40 [&_pre]:p-3 [&_ul]:my-2 [&_ul]:list-disc [&_ul]:pl-5">
+                  <ReactMarkdown remarkPlugins={[remarkGfm]}>
+                    {message.content || "..."}
+                  </ReactMarkdown>
+                </div>
+              ) : (
+                <div className="whitespace-pre-wrap text-sm leading-relaxed text-foreground">
+                  {message.content}
+                </div>
+              )}
+            </div>
+          );
+        })}
+    </div>
+  );
+};
diff --git a/orchestrator/src/client/components/ghostwriter/RunControls.tsx b/orchestrator/src/client/components/ghostwriter/RunControls.tsx
new file mode 100644
index 0000000..d214384
--- /dev/null
+++ b/orchestrator/src/client/components/ghostwriter/RunControls.tsx
@@ -0,0 +1,45 @@
+import { Loader2, RefreshCcw, Square } from "lucide-react";
+import type React from "react";
+import { Button } from "@/components/ui/button";
+
+type RunControlsProps = {
+  isStreaming: boolean;
+  canRegenerate: boolean;
+  onStop: () => Promise<void>;
+  onRegenerate: () => Promise<void>;
+};
+
+export const RunControls: React.FC<RunControlsProps> = ({
+  isStreaming,
+  canRegenerate,
+  onStop,
+  onRegenerate,
+}) => {
+  return (
+    <div className="flex items-center justify-end gap-2">
+      {isStreaming ? (
+        <Button size="sm" variant="outline" onClick={() => void onStop()}>
+          <Square className="mr-1 h-3.5 w-3.5" />
+          Stop
+        </Button>
+      ) : (
+        <Button
+          size="sm"
+          variant="outline"
+          onClick={() => void onRegenerate()}
+          disabled={!canRegenerate}
+        >
+          <RefreshCcw className="mr-1 h-3.5 w-3.5" />
+          Regenerate
+        </Button>
+      )}
+
+      {isStreaming && (
+        <div className="inline-flex items-center gap-1 text-xs text-muted-foreground">
+          <Loader2 className="h-3.5 w-3.5 animate-spin" />
+          Generating
+        </div>
+      )}
+    </div>
+  );
+};
diff --git a/orchestrator/src/client/components/ghostwriter/StreamingMessage.tsx b/orchestrator/src/client/components/ghostwriter/StreamingMessage.tsx
new file mode 100644
index 0000000..05c94d9
--- /dev/null
+++ b/orchestrator/src/client/components/ghostwriter/StreamingMessage.tsx
@@ -0,0 +1,16 @@
+import type React from "react";
+
+type StreamingMessageProps = {
+  content: string;
+};
+
+export const StreamingMessage: React.FC<StreamingMessageProps> = ({
+  content,
+}) => {
+  return (
+    <div className="whitespace-pre-wrap text-sm leading-relaxed text-foreground">
+      {content}
+      <span className="ml-1 inline-block h-4 w-2 animate-pulse rounded bg-primary/60 align-middle" />
+    </div>
+  );
+};
diff --git a/orchestrator/src/client/components/ghostwriter/ThreadList.tsx b/orchestrator/src/client/components/ghostwriter/ThreadList.tsx
new file mode 100644
index 0000000..7c07b07
--- /dev/null
+++ b/orchestrator/src/client/components/ghostwriter/ThreadList.tsx
@@ -0,0 +1,140 @@
+import type { Job, JobChatThread } from "@shared/types";
+import type React from "react";
+import { Button } from "@/components/ui/button";
+import { cn } from "@/lib/utils";
+
+type ThreadListProps = {
+  job: Job;
+  threads: JobChatThread[];
+  previews: Record<string, string>;
+  activeThreadId: string | null;
+  onSelectThread: (threadId: string) => void;
+  onCreateThread: () => void;
+  disabled?: boolean;
+};
+
+function formatRelativeTime(value: string | null): string {
+  if (!value) return "Updated just now";
+  const date = new Date(value);
+  if (Number.isNaN(date.getTime())) return "Updated recently";
+  const diffMs = date.getTime() - Date.now();
+  const absMs = Math.abs(diffMs);
+
+  const minute = 60 * 1000;
+  const hour = 60 * minute;
+  const day = 24 * hour;
+  const rtf = new Intl.RelativeTimeFormat("en", { numeric: "auto" });
+
+  if (absMs < hour) {
+    const magnitudeMinutes = Math.max(1, Math.round(absMs / minute));
+    const minutes = Math.sign(diffMs) * magnitudeMinutes;
+    return `Updated ${rtf.format(minutes, "minute")}`;
+  }
+  if (absMs < day) {
+    const hours = Math.round(diffMs / hour);
+    return `Updated ${rtf.format(hours, "hour")}`;
+  }
+  const days = Math.round(diffMs / day);
+  return `Updated ${rtf.format(days, "day")}`;
+}
+
+function normalizeThreadTitle(input: string | null, fallback: string): string {
+  const value = input?.trim();
+  return value && value.length > 0 ? value : fallback;
+}
+
+export const ThreadList: React.FC<ThreadListProps> = ({
+  job,
+  threads,
+  previews,
+  activeThreadId,
+  onSelectThread,
+  onCreateThread,
+  disabled,
+}) => {
+  const titleCounts = new Map<string, number>();
+  threads.forEach((thread) => {
+    const normalized = normalizeThreadTitle(
+      thread.title,
+      `${job.title} @ ${job.employer}`,
+    );
+    titleCounts.set(normalized, (titleCounts.get(normalized) ?? 0) + 1);
+  });
+
+  const seenTitles = new Map<string, number>();
+
+  return (
+    <aside className="min-h-0 space-y-3 pr-0 md:pr-4">
+      <div className="flex items-center justify-between">
+        <div className="text-[11px] font-medium uppercase tracking-wide text-muted-foreground">
+          Threads
+        </div>
+        <Button
+          size="sm"
+          variant="outline"
+          onClick={onCreateThread}
+          disabled={disabled}
+          className="h-8 px-2.5 text-xs"
+        >
+          New
+        </Button>
+      </div>
+
+      <div className="max-h-[13rem] space-y-1 overflow-auto pr-1">
+        {threads.length === 0 ? (
+          <div className="p-2 text-xs text-muted-foreground">
+            No threads yet
+          </div>
+        ) : (
+          threads.map((thread) => {
+            const rawTitle = normalizeThreadTitle(
+              thread.title,
+              `${job.title} @ ${job.employer}`,
+            );
+            const seenCount = (seenTitles.get(rawTitle) ?? 0) + 1;
+            seenTitles.set(rawTitle, seenCount);
+            const hasDuplicates = (titleCounts.get(rawTitle) ?? 0) > 1;
+            const title = hasDuplicates
+              ? `${rawTitle} (${seenCount})`
+              : rawTitle;
+            const preview = previews[thread.id]?.trim() || "No messages yet";
+            const isActive = activeThreadId === thread.id;
+
+            return (
+              <button
+                key={thread.id}
+                type="button"
+                onClick={() => onSelectThread(thread.id)}
+                disabled={disabled}
+                className={cn(
+                  "relative w-full rounded-md border px-3 py-2.5 text-left transition-colors",
+                  isActive
+                    ? "border-foreground/25 bg-accent text-accent-foreground"
+                    : "border-transparent hover:border-border/50 hover:bg-muted/40",
+                )}
+              >
+                {isActive && (
+                  <span className="absolute bottom-2 left-0 top-2 w-0.5 rounded-r bg-foreground" />
+                )}
+                <div
+                  className={cn(
+                    "truncate pr-2 text-xs",
+                    isActive ? "font-semibold" : "font-medium text-foreground",
+                  )}
+                >
+                  {title}
+                </div>
+                <div className="mt-1 text-[10px] text-muted-foreground">
+                  {formatRelativeTime(thread.lastMessageAt ?? thread.updatedAt)}
+                </div>
+                <div className="mt-1 truncate text-[11px] text-muted-foreground/90">
+                  {preview}
+                </div>
+              </button>
+            );
+          })
+        )}
+      </div>
+    </aside>
+  );
+};
diff --git a/orchestrator/src/client/hooks/useHotkeys.ts b/orchestrator/src/client/hooks/useHotkeys.ts
index ec512e9..b1ebab5 100644
--- a/orchestrator/src/client/hooks/useHotkeys.ts
+++ b/orchestrator/src/client/hooks/useHotkeys.ts
@@ -8,7 +8,7 @@ type KeyBindingMap = Record<string, (event: KeyboardEvent) => void>;
  * don't fire while the user is typing in a form control.
  */
 const INPUT_TAG_NAMES = new Set(["INPUT", "TEXTAREA", "SELECT"]);
-const MODIFIER_PATTERN = /(?:^|\+)(\$mod|Shift|Control|Meta|Alt)(?:\+|$)/;
+const NON_SHIFT_MODIFIER_PATTERN = /(?:^|\+)(\$mod|Control|Meta|Alt)(?:\+|$)/;
 
 function isEditableTarget(event: KeyboardEvent): boolean {
   const target = event.target;
@@ -27,8 +27,10 @@ function isEditableTarget(event: KeyboardEvent): boolean {
  * - Uses a stable ref for handler updates without rebinding.
  * - Rebuilds bindings when the key set changes.
  *
- * Modifier shortcuts (e.g. "$mod+K") bypass the input guard because the user
- * explicitly held a modifier -- those are intentional even inside inputs.
+ * Non-shift modifier shortcuts (e.g. "$mod+K") bypass the input guard because
+ * the user explicitly held a non-text modifier. Shift-only shortcuts (e.g.
+ * "Shift+?") stay blocked in inputs so typing punctuation doesn't trigger app
+ * hotkeys.
  */
 export function useHotkeys(
   bindings: KeyBindingMap,
@@ -49,13 +51,13 @@ export function useHotkeys(
     const guarded: KeyBindingMap = {};
     const bindingKeys = bindingSignature ? bindingSignature.split("|") : [];
     for (const key of bindingKeys) {
-      const hasModifier = key
+      const hasNonShiftModifier = key
         .split(" ")
-        .some((sequence) => MODIFIER_PATTERN.test(sequence));
+        .some((sequence) => NON_SHIFT_MODIFIER_PATTERN.test(sequence));
 
       guarded[key] = (event: KeyboardEvent) => {
         // Skip single-key shortcuts when the user is typing in an input.
-        if (!hasModifier && isEditableTarget(event)) return;
+        if (!hasNonShiftModifier && isEditableTarget(event)) return;
         bindingsRef.current[key]?.(event);
       };
     }
diff --git a/orchestrator/src/client/pages/JobPage.tsx b/orchestrator/src/client/pages/JobPage.tsx
index 62c371e..46cb0d5 100644
--- a/orchestrator/src/client/pages/JobPage.tsx
+++ b/orchestrator/src/client/pages/JobPage.tsx
@@ -23,6 +23,7 @@ import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
 import { formatTimestamp } from "@/lib/utils";
 import * as api from "../api";
 import { ConfirmDelete } from "../components/ConfirmDelete";
+import { GhostwriterDrawer } from "../components/ghostwriter/GhostwriterDrawer";
 import { JobHeader } from "../components/JobHeader";
 import {
   type LogEventFormValues,
@@ -273,10 +274,13 @@ export const JobPage: React.FC = () => {
         <div className="space-y-4">
           <Card className="border-border/50">
             <CardHeader>
-              <CardTitle className="flex items-center gap-2 text-base">
-                <CalendarClock className="h-4 w-4" />
-                Application details
-              </CardTitle>
+              <div className="flex items-center justify-between gap-3">
+                <CardTitle className="flex items-center gap-2 text-base">
+                  <CalendarClock className="h-4 w-4" />
+                  Application details
+                </CardTitle>
+                <GhostwriterDrawer job={job} />
+              </div>
             </CardHeader>
             <CardContent className="space-y-4">
               <div>
diff --git a/orchestrator/src/client/pages/OrchestratorPage.test.tsx b/orchestrator/src/client/pages/OrchestratorPage.test.tsx
index a47fcf0..a441fe5 100644
--- a/orchestrator/src/client/pages/OrchestratorPage.test.tsx
+++ b/orchestrator/src/client/pages/OrchestratorPage.test.tsx
@@ -1030,7 +1030,7 @@ describe("OrchestratorPage", () => {
 
     pressKeyOn(input, "?", { shiftKey: true });
     await waitFor(() => {
-      expect(screen.getByTestId("help-dialog")).toHaveTextContent("open");
+      expect(screen.getByTestId("help-dialog")).toHaveTextContent("closed");
     });
   });
 });
diff --git a/orchestrator/src/client/pages/SettingsPage.tsx b/orchestrator/src/client/pages/SettingsPage.tsx
index 938a18e..66f80c1 100644
--- a/orchestrator/src/client/pages/SettingsPage.tsx
+++ b/orchestrator/src/client/pages/SettingsPage.tsx
@@ -1,6 +1,7 @@
 import * as api from "@client/api";
 import { PageHeader } from "@client/components/layout";
 import { BackupSettingsSection } from "@client/pages/settings/components/BackupSettingsSection";
+import { ChatSettingsSection } from "@client/pages/settings/components/ChatSettingsSection";
 import { DangerZoneSection } from "@client/pages/settings/components/DangerZoneSection";
 import { DisplaySettingsSection } from "@client/pages/settings/components/DisplaySettingsSection";
 import { EnvironmentSettingsSection } from "@client/pages/settings/components/EnvironmentSettingsSection";
@@ -46,6 +47,10 @@ const DEFAULT_FORM_VALUES: UpdateSettingsInput = {
   resumeProjects: null,
   rxresumeBaseResumeId: null,
   showSponsorInfo: null,
+  chatStyleTone: "",
+  chatStyleFormality: "",
+  chatStyleConstraints: "",
+  chatStyleDoNotUse: "",
   rxresumeEmail: "",
   rxresumePassword: "",
   basicAuthUser: "",
@@ -81,6 +86,10 @@ const NULL_SETTINGS_PAYLOAD: UpdateSettingsInput = {
   resumeProjects: null,
   rxresumeBaseResumeId: null,
   showSponsorInfo: null,
+  chatStyleTone: null,
+  chatStyleFormality: null,
+  chatStyleConstraints: null,
+  chatStyleDoNotUse: null,
   rxresumeEmail: null,
   rxresumePassword: null,
   basicAuthUser: null,
@@ -110,6 +119,10 @@ const mapSettingsToForm = (data: AppSettings): UpdateSettingsInput => ({
   resumeProjects: data.resumeProjects,
   rxresumeBaseResumeId: data.rxresumeBaseResumeId ?? null,
   showSponsorInfo: data.overrideShowSponsorInfo,
+  chatStyleTone: data.overrideChatStyleTone ?? "",
+  chatStyleFormality: data.overrideChatStyleFormality ?? "",
+  chatStyleConstraints: data.overrideChatStyleConstraints ?? "",
+  chatStyleDoNotUse: data.overrideChatStyleDoNotUse ?? "",
   rxresumeEmail: data.rxresumeEmail ?? "",
   rxresumePassword: "",
   basicAuthUser: data.basicAuthUser ?? "",
@@ -200,6 +213,24 @@ const getDerivedSettings = (settings: AppSettings | null) => {
       effective: settings?.showSponsorInfo ?? true,
       default: settings?.defaultShowSponsorInfo ?? true,
     },
+    chat: {
+      tone: {
+        effective: settings?.chatStyleTone ?? "professional",
+        default: settings?.defaultChatStyleTone ?? "professional",
+      },
+      formality: {
+        effective: settings?.chatStyleFormality ?? "medium",
+        default: settings?.defaultChatStyleFormality ?? "medium",
+      },
+      constraints: {
+        effective: settings?.chatStyleConstraints ?? "",
+        default: settings?.defaultChatStyleConstraints ?? "",
+      },
+      doNotUse: {
+        effective: settings?.chatStyleDoNotUse ?? "",
+        default: settings?.defaultChatStyleDoNotUse ?? "",
+      },
+    },
     envSettings: {
       readable: {
         rxresumeEmail: settings?.rxresumeEmail ?? "",
@@ -386,6 +417,7 @@ export const SettingsPage: React.FC = () => {
     pipelineWebhook,
     jobCompleteWebhook,
     display,
+    chat,
     envSettings,
     defaultResumeProjects,
     profileProjects,
@@ -551,6 +583,10 @@ export const SettingsPage: React.FC = () => {
         resumeProjects: resumeProjectsOverride,
         rxresumeBaseResumeId: normalizeString(data.rxresumeBaseResumeId),
         showSponsorInfo: nullIfSame(data.showSponsorInfo, display.default),
+        chatStyleTone: normalizeString(data.chatStyleTone),
+        chatStyleFormality: normalizeString(data.chatStyleFormality),
+        chatStyleConstraints: normalizeString(data.chatStyleConstraints),
+        chatStyleDoNotUse: normalizeString(data.chatStyleDoNotUse),
         backupEnabled: nullIfSame(
           data.backupEnabled,
           backup.backupEnabled.default,
@@ -730,6 +766,11 @@ export const SettingsPage: React.FC = () => {
             isLoading={isLoading}
             isSaving={isSaving}
           />
+          <ChatSettingsSection
+            values={chat}
+            isLoading={isLoading}
+            isSaving={isSaving}
+          />
           <ScoringSettingsSection
             values={scoring}
             isLoading={isLoading}
diff --git a/orchestrator/src/client/pages/orchestrator/JobDetailPanel.tsx b/orchestrator/src/client/pages/orchestrator/JobDetailPanel.tsx
index 25e6e11..06dfe94 100644
--- a/orchestrator/src/client/pages/orchestrator/JobDetailPanel.tsx
+++ b/orchestrator/src/client/pages/orchestrator/JobDetailPanel.tsx
@@ -580,7 +580,7 @@ export const JobDetailPanel: React.FC<JobDetailPanelProps> = ({
                 className="text-[10px] text-muted-foreground/60 hover:text-muted-foreground transition-colors"
                 onClick={() => setDetailTab("description")}
               >
-                View full description 
+                View full description
               </button>
             </div>
           </div>
diff --git a/orchestrator/src/client/pages/settings/components/ChatSettingsSection.tsx b/orchestrator/src/client/pages/settings/components/ChatSettingsSection.tsx
new file mode 100644
index 0000000..812a825
--- /dev/null
+++ b/orchestrator/src/client/pages/settings/components/ChatSettingsSection.tsx
@@ -0,0 +1,138 @@
+import { SettingsInput } from "@client/pages/settings/components/SettingsInput";
+import type { ChatValues } from "@client/pages/settings/types";
+import type { UpdateSettingsInput } from "@shared/settings-schema.js";
+import type React from "react";
+import { Controller, useFormContext } from "react-hook-form";
+import {
+  AccordionContent,
+  AccordionItem,
+  AccordionTrigger,
+} from "@/components/ui/accordion";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
+import { Separator } from "@/components/ui/separator";
+
+type ChatSettingsSectionProps = {
+  values: ChatValues;
+  isLoading: boolean;
+  isSaving: boolean;
+};
+
+export const ChatSettingsSection: React.FC<ChatSettingsSectionProps> = ({
+  values,
+  isLoading,
+  isSaving,
+}) => {
+  const { tone, formality, constraints, doNotUse } = values;
+
+  const { control, register } = useFormContext<UpdateSettingsInput>();
+
+  return (
+    <AccordionItem value="chat" className="border rounded-lg px-4">
+      <AccordionTrigger className="hover:no-underline py-4">
+        <span className="text-base font-semibold">Ghostwriter</span>
+      </AccordionTrigger>
+      <AccordionContent className="pb-4">
+        <div className="space-y-4">
+          <div className="grid gap-4 md:grid-cols-2">
+            <div className="space-y-2">
+              <label htmlFor="chatStyleTone" className="text-sm font-medium">
+                Tone
+              </label>
+              <Controller
+                name="chatStyleTone"
+                control={control}
+                render={({ field }) => (
+                  <Select
+                    value={field.value || tone.default}
+                    onValueChange={(value) => field.onChange(value)}
+                    disabled={isLoading || isSaving}
+                  >
+                    <SelectTrigger id="chatStyleTone">
+                      <SelectValue placeholder="Select tone" />
+                    </SelectTrigger>
+                    <SelectContent>
+                      <SelectItem value="professional">Professional</SelectItem>
+                      <SelectItem value="concise">Concise</SelectItem>
+                      <SelectItem value="direct">Direct</SelectItem>
+                      <SelectItem value="friendly">Friendly</SelectItem>
+                    </SelectContent>
+                  </Select>
+                )}
+              />
+            </div>
+
+            <div className="space-y-2">
+              <label
+                htmlFor="chatStyleFormality"
+                className="text-sm font-medium"
+              >
+                Formality
+              </label>
+              <Controller
+                name="chatStyleFormality"
+                control={control}
+                render={({ field }) => (
+                  <Select
+                    value={field.value || formality.default}
+                    onValueChange={(value) => field.onChange(value)}
+                    disabled={isLoading || isSaving}
+                  >
+                    <SelectTrigger id="chatStyleFormality">
+                      <SelectValue placeholder="Select formality" />
+                    </SelectTrigger>
+                    <SelectContent>
+                      <SelectItem value="low">Low</SelectItem>
+                      <SelectItem value="medium">Medium</SelectItem>
+                      <SelectItem value="high">High</SelectItem>
+                    </SelectContent>
+                  </Select>
+                )}
+              />
+            </div>
+          </div>
+
+          <SettingsInput
+            label="Constraints"
+            inputProps={register("chatStyleConstraints")}
+            placeholder="Example: keep answers under 120 words and include bullet points"
+            disabled={isLoading || isSaving}
+            helper="Optional global writing constraints used by Ghostwriter replies."
+            current={constraints.effective || "—"}
+          />
+
+          <SettingsInput
+            label="Do-not-use terms"
+            inputProps={register("chatStyleDoNotUse")}
+            placeholder="Example: synergize, leverage"
+            disabled={isLoading || isSaving}
+            helper="Optional comma-separated words or phrases to avoid."
+            current={doNotUse.effective || "—"}
+          />
+
+          <Separator />
+
+          <div className="grid gap-2 text-sm sm:grid-cols-2">
+            <div>
+              <div className="text-xs text-muted-foreground">Tone</div>
+              <div className="break-words font-mono text-xs">
+                Effective: {tone.effective} | Default: {tone.default}
+              </div>
+            </div>
+            <div>
+              <div className="text-xs text-muted-foreground">Formality</div>
+              <div className="break-words font-mono text-xs">
+                Effective: {formality.effective} | Default: {formality.default}
+              </div>
+            </div>
+          </div>
+        </div>
+      </AccordionContent>
+    </AccordionItem>
+  );
+};
diff --git a/orchestrator/src/client/pages/settings/types.ts b/orchestrator/src/client/pages/settings/types.ts
index 51f0e1a..cc2af77 100644
--- a/orchestrator/src/client/pages/settings/types.ts
+++ b/orchestrator/src/client/pages/settings/types.ts
@@ -14,6 +14,12 @@ export type ModelValues = EffectiveDefault<string> & {
 
 export type WebhookValues = EffectiveDefault<string>;
 export type DisplayValues = EffectiveDefault<boolean>;
+export type ChatValues = {
+  tone: EffectiveDefault<string>;
+  formality: EffectiveDefault<string>;
+  constraints: EffectiveDefault<string>;
+  doNotUse: EffectiveDefault<string>;
+};
 
 export type EnvSettingsValues = {
   readable: {
diff --git a/orchestrator/src/components/ui/button.tsx b/orchestrator/src/components/ui/button.tsx
index 3aa47de..9bdee0c 100644
--- a/orchestrator/src/components/ui/button.tsx
+++ b/orchestrator/src/components/ui/button.tsx
@@ -5,7 +5,7 @@ import * as React from "react";
 import { cn } from "@/lib/utils";
 
 const buttonVariants = cva(
-  "inline-flex items-center justify-center gap-2 whitespace-nowrap rounded-md text-sm font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50 [&_svg]:pointer-events-none [&_svg]:size-4 [&_svg]:shrink-0",
+  "inline-flex cursor-pointer items-center justify-center gap-2 whitespace-nowrap rounded-md text-sm font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50 [&_svg]:pointer-events-none [&_svg]:size-4 [&_svg]:shrink-0",
   {
     variants: {
       variant: {
diff --git a/orchestrator/src/server/api/routes.ts b/orchestrator/src/server/api/routes.ts
index bfc67ac..5abfd19 100644
--- a/orchestrator/src/server/api/routes.ts
+++ b/orchestrator/src/server/api/routes.ts
@@ -6,6 +6,7 @@ import { Router } from "express";
 import { backupRouter } from "./routes/backup";
 import { databaseRouter } from "./routes/database";
 import { demoRouter } from "./routes/demo";
+import { ghostwriterRouter } from "./routes/ghostwriter";
 import { jobsRouter } from "./routes/jobs";
 import { manualJobsRouter } from "./routes/manual-jobs";
 import { onboardingRouter } from "./routes/onboarding";
@@ -20,6 +21,7 @@ import { webhookRouter } from "./routes/webhook";
 export const apiRouter = Router();
 
 apiRouter.use("/jobs", jobsRouter);
+apiRouter.use("/jobs/:id/chat", ghostwriterRouter);
 apiRouter.use("/demo", demoRouter);
 apiRouter.use("/settings", settingsRouter);
 apiRouter.use("/pipeline", pipelineRouter);
diff --git a/orchestrator/src/server/api/routes/ghostwriter.test.ts b/orchestrator/src/server/api/routes/ghostwriter.test.ts
new file mode 100644
index 0000000..25fe210
--- /dev/null
+++ b/orchestrator/src/server/api/routes/ghostwriter.test.ts
@@ -0,0 +1,185 @@
+import type { Server } from "node:http";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { startServer, stopServer } from "./test-utils";
+
+vi.mock("../../services/ghostwriter", () => ({
+  listThreads: vi.fn(async () => [
+    {
+      id: "thread-1",
+      jobId: "job-1",
+      title: "Thread",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+      lastMessageAt: new Date().toISOString(),
+    },
+  ]),
+  createThread: vi.fn(
+    async (input: { jobId: string; title?: string | null }) => ({
+      id: "thread-created",
+      jobId: input.jobId,
+      title: input.title ?? null,
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+      lastMessageAt: null,
+    }),
+  ),
+  listMessages: vi.fn(async () => [
+    {
+      id: "message-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      role: "user",
+      content: "hello",
+      status: "complete",
+      tokensIn: 1,
+      tokensOut: null,
+      version: 1,
+      replacesMessageId: null,
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    },
+  ]),
+  listMessagesForJob: vi.fn(async () => [
+    {
+      id: "message-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      role: "user",
+      content: "hello",
+      status: "complete",
+      tokensIn: 1,
+      tokensOut: null,
+      version: 1,
+      replacesMessageId: null,
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    },
+  ]),
+  sendMessage: vi.fn(async () => ({
+    userMessage: {
+      id: "user-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      role: "user",
+      content: "hello",
+      status: "complete",
+      tokensIn: 1,
+      tokensOut: null,
+      version: 1,
+      replacesMessageId: null,
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    },
+    assistantMessage: {
+      id: "assistant-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      role: "assistant",
+      content: "hi",
+      status: "complete",
+      tokensIn: 1,
+      tokensOut: 1,
+      version: 1,
+      replacesMessageId: null,
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    },
+    runId: "run-1",
+  })),
+  sendMessageForJob: vi.fn(async () => ({
+    userMessage: {
+      id: "user-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      role: "user",
+      content: "hello",
+      status: "complete",
+      tokensIn: 1,
+      tokensOut: null,
+      version: 1,
+      replacesMessageId: null,
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    },
+    assistantMessage: {
+      id: "assistant-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      role: "assistant",
+      content: "hi",
+      status: "complete",
+      tokensIn: 1,
+      tokensOut: 1,
+      version: 1,
+      replacesMessageId: null,
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    },
+    runId: "run-1",
+  })),
+  cancelRun: vi.fn(async () => ({ cancelled: true, alreadyFinished: false })),
+  regenerateMessage: vi.fn(async () => ({
+    runId: "run-2",
+    assistantMessage: {
+      id: "assistant-2",
+      threadId: "thread-1",
+      jobId: "job-1",
+      role: "assistant",
+      content: "updated",
+      status: "complete",
+      tokensIn: 1,
+      tokensOut: 1,
+      version: 2,
+      replacesMessageId: "assistant-1",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    },
+  })),
+}));
+
+describe.sequential("Ghostwriter API", () => {
+  let server: Server;
+  let baseUrl: string;
+  let closeDb: () => void;
+  let tempDir: string;
+
+  beforeEach(async () => {
+    ({ server, baseUrl, closeDb, tempDir } = await startServer());
+  });
+
+  afterEach(async () => {
+    await stopServer({ server, closeDb, tempDir });
+  });
+
+  it("lists messages with request id metadata", async () => {
+    const res = await fetch(`${baseUrl}/api/jobs/job-1/chat/messages`, {
+      headers: {
+        "x-request-id": "chat-req-1",
+      },
+    });
+    const body = await res.json();
+
+    expect(res.status).toBe(200);
+    expect(res.headers.get("x-request-id")).toBe("chat-req-1");
+    expect(body.ok).toBe(true);
+    expect(body.data.messages.length).toBe(1);
+    expect(body.meta.requestId).toBe("chat-req-1");
+  });
+
+  it("sends a message in the per-job conversation", async () => {
+    const messageRes = await fetch(`${baseUrl}/api/jobs/job-1/chat/messages`, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({ content: "hello" }),
+    });
+    const messageBody = await messageRes.json();
+
+    expect(messageRes.status).toBe(200);
+    expect(messageBody.ok).toBe(true);
+    expect(messageBody.data.runId).toBe("run-1");
+    expect(messageBody.data.assistantMessage.role).toBe("assistant");
+    expect(typeof messageBody.meta.requestId).toBe("string");
+  });
+});
diff --git a/orchestrator/src/server/api/routes/ghostwriter.ts b/orchestrator/src/server/api/routes/ghostwriter.ts
new file mode 100644
index 0000000..0ef7dc5
--- /dev/null
+++ b/orchestrator/src/server/api/routes/ghostwriter.ts
@@ -0,0 +1,638 @@
+import { asyncRoute, fail, ok } from "@infra/http";
+import { logger } from "@infra/logger";
+import { runWithRequestContext } from "@infra/request-context";
+import { badRequest, toAppError } from "@server/infra/errors";
+import { type Request, type Response, Router } from "express";
+import { z } from "zod";
+import * as ghostwriterService from "../../services/ghostwriter";
+
+export const ghostwriterRouter = Router({ mergeParams: true });
+
+const createThreadSchema = z.object({
+  title: z.string().trim().max(200).nullable().optional(),
+});
+
+const listMessagesQuerySchema = z.object({
+  limit: z.coerce.number().int().min(1).max(500).optional(),
+  offset: z.coerce.number().int().min(0).max(10000).optional(),
+});
+
+const sendMessageSchema = z.object({
+  content: z.string().trim().min(1).max(20000),
+  stream: z.boolean().optional(),
+});
+
+const regenerateSchema = z.object({
+  stream: z.boolean().optional(),
+});
+
+function getJobId(req: Request): string {
+  const jobId = req.params.id;
+  if (!jobId) {
+    throw badRequest("Missing job id");
+  }
+  return jobId;
+}
+
+function writeSse(res: Response, event: unknown): void {
+  if (res.writableEnded || res.destroyed) return;
+  res.write(`data: ${JSON.stringify(event)}\n\n`);
+}
+
+function setupSseStream(
+  req: Request,
+  res: Response,
+  onDisconnectRun?: (runId: string) => Promise<void>,
+): {
+  setRunId: (runId: string) => void;
+  isClosed: () => boolean;
+  cleanup: () => void;
+} {
+  res.status(200);
+  res.setHeader("Content-Type", "text/event-stream");
+  res.setHeader("Cache-Control", "no-cache, no-transform");
+  res.setHeader("Connection", "keep-alive");
+  res.setHeader("X-Accel-Buffering", "no");
+  res.flushHeaders?.();
+
+  let closed = false;
+  let activeRunId: string | null = null;
+  let disconnectHandled = false;
+
+  const handleDisconnect = () => {
+    if (disconnectHandled) return;
+    disconnectHandled = true;
+    if (!activeRunId || !onDisconnectRun) return;
+
+    void onDisconnectRun(activeRunId).catch((error) => {
+      logger.warn("Ghostwriter stream disconnect cancellation failed", {
+        runId: activeRunId,
+        error,
+      });
+    });
+  };
+
+  const heartbeat = setInterval(() => {
+    if (res.writableEnded || res.destroyed) return;
+    res.write(": heartbeat\n\n");
+  }, 30000);
+
+  const onClose = () => {
+    closed = true;
+    clearInterval(heartbeat);
+    handleDisconnect();
+  };
+
+  req.on("close", onClose);
+
+  return {
+    setRunId: (runId: string) => {
+      activeRunId = runId;
+      if (closed) {
+        handleDisconnect();
+      }
+    },
+    isClosed: () => closed,
+    cleanup: () => {
+      clearInterval(heartbeat);
+      req.off("close", onClose);
+    },
+  };
+}
+
+ghostwriterRouter.get(
+  "/messages",
+  asyncRoute(async (req, res) => {
+    const jobId = getJobId(req);
+    const parsed = listMessagesQuerySchema.safeParse(req.query);
+    if (!parsed.success) {
+      return fail(
+        res,
+        badRequest(parsed.error.message, parsed.error.flatten()),
+      );
+    }
+
+    await runWithRequestContext({ jobId }, async () => {
+      const messages = await ghostwriterService.listMessagesForJob({
+        jobId,
+        limit: parsed.data.limit,
+        offset: parsed.data.offset,
+      });
+      ok(res, { messages });
+    });
+  }),
+);
+
+ghostwriterRouter.post(
+  "/messages",
+  asyncRoute(async (req, res) => {
+    const jobId = getJobId(req);
+
+    const parsed = sendMessageSchema.safeParse(req.body);
+    if (!parsed.success) {
+      return fail(
+        res,
+        badRequest(parsed.error.message, parsed.error.flatten()),
+      );
+    }
+
+    await runWithRequestContext({ jobId }, async () => {
+      if (parsed.data.stream) {
+        const sse = setupSseStream(req, res, async (runId: string) => {
+          await ghostwriterService.cancelRunForJob({
+            jobId,
+            runId,
+          });
+        });
+
+        try {
+          await ghostwriterService.sendMessageForJob({
+            jobId,
+            content: parsed.data.content,
+            stream: {
+              onReady: ({ runId, threadId, messageId, requestId }) => {
+                sse.setRunId(runId);
+                if (sse.isClosed()) return;
+                writeSse(res, {
+                  type: "ready",
+                  runId,
+                  threadId,
+                  messageId,
+                  requestId,
+                });
+              },
+              onDelta: ({ runId, messageId, delta }) =>
+                writeSse(res, {
+                  type: "delta",
+                  runId,
+                  messageId,
+                  delta,
+                }),
+              onCompleted: ({ runId, message }) =>
+                writeSse(res, {
+                  type: "completed",
+                  runId,
+                  message,
+                }),
+              onCancelled: ({ runId, message }) =>
+                writeSse(res, {
+                  type: "cancelled",
+                  runId,
+                  message,
+                }),
+              onError: ({ runId, code, message, requestId }) =>
+                writeSse(res, {
+                  type: "error",
+                  runId,
+                  code,
+                  message,
+                  requestId,
+                }),
+            },
+          });
+        } catch (error) {
+          const appError = toAppError(error);
+          writeSse(res, {
+            type: "error",
+            code: appError.code,
+            message: appError.message,
+            requestId: res.getHeader("x-request-id") || "unknown",
+          });
+        } finally {
+          sse.cleanup();
+          if (!res.writableEnded) {
+            res.end();
+          }
+        }
+
+        return;
+      }
+
+      const result = await ghostwriterService.sendMessageForJob({
+        jobId,
+        content: parsed.data.content,
+      });
+
+      ok(res, {
+        userMessage: result.userMessage,
+        assistantMessage: result.assistantMessage,
+        runId: result.runId,
+      });
+    });
+  }),
+);
+
+ghostwriterRouter.post(
+  "/runs/:runId/cancel",
+  asyncRoute(async (req, res) => {
+    const jobId = getJobId(req);
+    const runId = req.params.runId;
+    if (!runId) {
+      return fail(res, badRequest("Missing run id"));
+    }
+
+    await runWithRequestContext({ jobId }, async () => {
+      const result = await ghostwriterService.cancelRunForJob({
+        jobId,
+        runId,
+      });
+
+      ok(res, result);
+    });
+  }),
+);
+
+ghostwriterRouter.post(
+  "/messages/:assistantMessageId/regenerate",
+  asyncRoute(async (req, res) => {
+    const jobId = getJobId(req);
+    const assistantMessageId = req.params.assistantMessageId;
+    if (!assistantMessageId) {
+      return fail(res, badRequest("Missing message id"));
+    }
+
+    const parsed = regenerateSchema.safeParse(req.body ?? {});
+    if (!parsed.success) {
+      return fail(
+        res,
+        badRequest(parsed.error.message, parsed.error.flatten()),
+      );
+    }
+
+    await runWithRequestContext({ jobId }, async () => {
+      if (parsed.data.stream) {
+        const sse = setupSseStream(req, res, async (runId: string) => {
+          await ghostwriterService.cancelRunForJob({
+            jobId,
+            runId,
+          });
+        });
+
+        try {
+          await ghostwriterService.regenerateMessageForJob({
+            jobId,
+            assistantMessageId,
+            stream: {
+              onReady: ({ runId, threadId, messageId, requestId }) => {
+                sse.setRunId(runId);
+                if (sse.isClosed()) return;
+                writeSse(res, {
+                  type: "ready",
+                  runId,
+                  threadId,
+                  messageId,
+                  requestId,
+                });
+              },
+              onDelta: ({ runId, messageId, delta }) =>
+                writeSse(res, {
+                  type: "delta",
+                  runId,
+                  messageId,
+                  delta,
+                }),
+              onCompleted: ({ runId, message }) =>
+                writeSse(res, {
+                  type: "completed",
+                  runId,
+                  message,
+                }),
+              onCancelled: ({ runId, message }) =>
+                writeSse(res, {
+                  type: "cancelled",
+                  runId,
+                  message,
+                }),
+              onError: ({ runId, code, message, requestId }) =>
+                writeSse(res, {
+                  type: "error",
+                  runId,
+                  code,
+                  message,
+                  requestId,
+                }),
+            },
+          });
+        } catch (error) {
+          const appError = toAppError(error);
+          writeSse(res, {
+            type: "error",
+            code: appError.code,
+            message: appError.message,
+            requestId: res.getHeader("x-request-id") || "unknown",
+          });
+        } finally {
+          sse.cleanup();
+          if (!res.writableEnded) {
+            res.end();
+          }
+        }
+
+        return;
+      }
+
+      const result = await ghostwriterService.regenerateMessageForJob({
+        jobId,
+        assistantMessageId,
+      });
+
+      ok(res, result);
+    });
+  }),
+);
+
+ghostwriterRouter.get(
+  "/threads",
+  asyncRoute(async (req, res) => {
+    const jobId = getJobId(req);
+
+    await runWithRequestContext({ jobId }, async () => {
+      const threads = await ghostwriterService.listThreads(jobId);
+      ok(res, { threads });
+    });
+  }),
+);
+
+ghostwriterRouter.post(
+  "/threads",
+  asyncRoute(async (req, res) => {
+    const jobId = getJobId(req);
+    const parsed = createThreadSchema.safeParse(req.body);
+    if (!parsed.success) {
+      return fail(
+        res,
+        badRequest(parsed.error.message, parsed.error.flatten()),
+      );
+    }
+
+    await runWithRequestContext({ jobId }, async () => {
+      const thread = await ghostwriterService.createThread({
+        jobId,
+        title: parsed.data.title,
+      });
+      ok(res, { thread }, 201);
+    });
+  }),
+);
+
+ghostwriterRouter.get(
+  "/threads/:threadId/messages",
+  asyncRoute(async (req, res) => {
+    const jobId = getJobId(req);
+    const threadId = req.params.threadId;
+    if (!threadId) {
+      return fail(res, badRequest("Missing thread id"));
+    }
+
+    const parsed = listMessagesQuerySchema.safeParse(req.query);
+    if (!parsed.success) {
+      return fail(
+        res,
+        badRequest(parsed.error.message, parsed.error.flatten()),
+      );
+    }
+
+    await runWithRequestContext({ jobId }, async () => {
+      const messages = await ghostwriterService.listMessages({
+        jobId,
+        threadId,
+        limit: parsed.data.limit,
+        offset: parsed.data.offset,
+      });
+      ok(res, { messages });
+    });
+  }),
+);
+
+ghostwriterRouter.post(
+  "/threads/:threadId/messages",
+  asyncRoute(async (req, res) => {
+    const jobId = getJobId(req);
+    const threadId = req.params.threadId;
+    if (!threadId) {
+      return fail(res, badRequest("Missing thread id"));
+    }
+
+    const parsed = sendMessageSchema.safeParse(req.body);
+    if (!parsed.success) {
+      return fail(
+        res,
+        badRequest(parsed.error.message, parsed.error.flatten()),
+      );
+    }
+
+    await runWithRequestContext({ jobId }, async () => {
+      if (parsed.data.stream) {
+        const sse = setupSseStream(req, res, async (runId: string) => {
+          await ghostwriterService.cancelRun({
+            jobId,
+            threadId,
+            runId,
+          });
+        });
+
+        try {
+          await ghostwriterService.sendMessage({
+            jobId,
+            threadId,
+            content: parsed.data.content,
+            stream: {
+              onReady: ({ runId, messageId, requestId }) => {
+                sse.setRunId(runId);
+                if (sse.isClosed()) return;
+                writeSse(res, {
+                  type: "ready",
+                  runId,
+                  threadId,
+                  messageId,
+                  requestId,
+                });
+              },
+              onDelta: ({ runId, messageId, delta }) =>
+                writeSse(res, {
+                  type: "delta",
+                  runId,
+                  messageId,
+                  delta,
+                }),
+              onCompleted: ({ runId, message }) =>
+                writeSse(res, {
+                  type: "completed",
+                  runId,
+                  message,
+                }),
+              onCancelled: ({ runId, message }) =>
+                writeSse(res, {
+                  type: "cancelled",
+                  runId,
+                  message,
+                }),
+              onError: ({ runId, code, message, requestId }) =>
+                writeSse(res, {
+                  type: "error",
+                  runId,
+                  code,
+                  message,
+                  requestId,
+                }),
+            },
+          });
+        } catch (error) {
+          const appError = toAppError(error);
+          writeSse(res, {
+            type: "error",
+            code: appError.code,
+            message: appError.message,
+            requestId: res.getHeader("x-request-id") || "unknown",
+          });
+        } finally {
+          sse.cleanup();
+          if (!res.writableEnded) {
+            res.end();
+          }
+        }
+
+        return;
+      }
+
+      const result = await ghostwriterService.sendMessage({
+        jobId,
+        threadId,
+        content: parsed.data.content,
+      });
+
+      ok(res, {
+        userMessage: result.userMessage,
+        assistantMessage: result.assistantMessage,
+        runId: result.runId,
+      });
+    });
+  }),
+);
+
+ghostwriterRouter.post(
+  "/threads/:threadId/runs/:runId/cancel",
+  asyncRoute(async (req, res) => {
+    const jobId = getJobId(req);
+    const threadId = req.params.threadId;
+    const runId = req.params.runId;
+
+    if (!threadId || !runId) {
+      return fail(res, badRequest("Missing thread id or run id"));
+    }
+
+    await runWithRequestContext({ jobId }, async () => {
+      const result = await ghostwriterService.cancelRun({
+        jobId,
+        threadId,
+        runId,
+      });
+
+      ok(res, result);
+    });
+  }),
+);
+
+ghostwriterRouter.post(
+  "/threads/:threadId/messages/:assistantMessageId/regenerate",
+  asyncRoute(async (req, res) => {
+    const jobId = getJobId(req);
+    const threadId = req.params.threadId;
+    const assistantMessageId = req.params.assistantMessageId;
+
+    if (!threadId || !assistantMessageId) {
+      return fail(res, badRequest("Missing thread id or message id"));
+    }
+
+    const parsed = regenerateSchema.safeParse(req.body ?? {});
+    if (!parsed.success) {
+      return fail(
+        res,
+        badRequest(parsed.error.message, parsed.error.flatten()),
+      );
+    }
+
+    await runWithRequestContext({ jobId }, async () => {
+      if (parsed.data.stream) {
+        const sse = setupSseStream(req, res, async (runId: string) => {
+          await ghostwriterService.cancelRun({
+            jobId,
+            threadId,
+            runId,
+          });
+        });
+
+        try {
+          await ghostwriterService.regenerateMessage({
+            jobId,
+            threadId,
+            assistantMessageId,
+            stream: {
+              onReady: ({ runId, messageId, requestId }) => {
+                sse.setRunId(runId);
+                if (sse.isClosed()) return;
+                writeSse(res, {
+                  type: "ready",
+                  runId,
+                  threadId,
+                  messageId,
+                  requestId,
+                });
+              },
+              onDelta: ({ runId, messageId, delta }) =>
+                writeSse(res, {
+                  type: "delta",
+                  runId,
+                  messageId,
+                  delta,
+                }),
+              onCompleted: ({ runId, message }) =>
+                writeSse(res, {
+                  type: "completed",
+                  runId,
+                  message,
+                }),
+              onCancelled: ({ runId, message }) =>
+                writeSse(res, {
+                  type: "cancelled",
+                  runId,
+                  message,
+                }),
+              onError: ({ runId, code, message, requestId }) =>
+                writeSse(res, {
+                  type: "error",
+                  runId,
+                  code,
+                  message,
+                  requestId,
+                }),
+            },
+          });
+        } catch (error) {
+          const appError = toAppError(error);
+          writeSse(res, {
+            type: "error",
+            code: appError.code,
+            message: appError.message,
+            requestId: res.getHeader("x-request-id") || "unknown",
+          });
+        } finally {
+          sse.cleanup();
+          if (!res.writableEnded) {
+            res.end();
+          }
+        }
+
+        return;
+      }
+
+      const result = await ghostwriterService.regenerateMessage({
+        jobId,
+        threadId,
+        assistantMessageId,
+      });
+
+      ok(res, result);
+    });
+  }),
+);
diff --git a/orchestrator/src/server/db/migrate.ts b/orchestrator/src/server/db/migrate.ts
index 6d91149..cd73cec 100644
--- a/orchestrator/src/server/db/migrate.ts
+++ b/orchestrator/src/server/db/migrate.ts
@@ -92,6 +92,51 @@ const migrations = [
     updated_at TEXT NOT NULL DEFAULT (datetime('now'))
   )`,
 
+  `CREATE TABLE IF NOT EXISTS job_chat_threads (
+    id TEXT PRIMARY KEY,
+    job_id TEXT NOT NULL,
+    title TEXT,
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at TEXT NOT NULL DEFAULT (datetime('now')),
+    last_message_at TEXT,
+    FOREIGN KEY (job_id) REFERENCES jobs(id) ON DELETE CASCADE
+  )`,
+
+  `CREATE TABLE IF NOT EXISTS job_chat_messages (
+    id TEXT PRIMARY KEY,
+    thread_id TEXT NOT NULL,
+    job_id TEXT NOT NULL,
+    role TEXT NOT NULL CHECK(role IN ('system', 'user', 'assistant', 'tool')),
+    content TEXT NOT NULL DEFAULT '',
+    status TEXT NOT NULL DEFAULT 'partial' CHECK(status IN ('complete', 'partial', 'cancelled', 'failed')),
+    tokens_in INTEGER,
+    tokens_out INTEGER,
+    version INTEGER NOT NULL DEFAULT 1,
+    replaces_message_id TEXT,
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at TEXT NOT NULL DEFAULT (datetime('now')),
+    FOREIGN KEY (thread_id) REFERENCES job_chat_threads(id) ON DELETE CASCADE,
+    FOREIGN KEY (job_id) REFERENCES jobs(id) ON DELETE CASCADE
+  )`,
+
+  `CREATE TABLE IF NOT EXISTS job_chat_runs (
+    id TEXT PRIMARY KEY,
+    thread_id TEXT NOT NULL,
+    job_id TEXT NOT NULL,
+    status TEXT NOT NULL DEFAULT 'running' CHECK(status IN ('running', 'completed', 'cancelled', 'failed')),
+    model TEXT,
+    provider TEXT,
+    error_code TEXT,
+    error_message TEXT,
+    started_at INTEGER NOT NULL,
+    completed_at INTEGER,
+    request_id TEXT,
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at TEXT NOT NULL DEFAULT (datetime('now')),
+    FOREIGN KEY (thread_id) REFERENCES job_chat_threads(id) ON DELETE CASCADE,
+    FOREIGN KEY (job_id) REFERENCES jobs(id) ON DELETE CASCADE
+  )`,
+
   `CREATE TABLE IF NOT EXISTS stage_events (
     id TEXT PRIMARY KEY,
     application_id TEXT NOT NULL,
@@ -403,6 +448,28 @@ const migrations = [
   `CREATE INDEX IF NOT EXISTS idx_interviews_application_id ON interviews(application_id)`,
   `CREATE INDEX IF NOT EXISTS idx_post_app_sync_runs_provider_account_started_at ON post_application_sync_runs(provider, account_key, started_at)`,
   `CREATE INDEX IF NOT EXISTS idx_post_app_messages_provider_account_processing_status ON post_application_messages(provider, account_key, processing_status)`,
+  `CREATE INDEX IF NOT EXISTS idx_job_chat_threads_job_updated ON job_chat_threads(job_id, updated_at)`,
+  `CREATE INDEX IF NOT EXISTS idx_job_chat_messages_thread_created ON job_chat_messages(thread_id, created_at)`,
+  `CREATE INDEX IF NOT EXISTS idx_job_chat_runs_thread_status ON job_chat_runs(thread_id, status)`,
+  // Ensure only one running run per thread; backfill any duplicates first.
+  `WITH ranked AS (
+      SELECT
+        id,
+        ROW_NUMBER() OVER (PARTITION BY thread_id ORDER BY started_at DESC, id DESC) AS rank_in_thread
+      FROM job_chat_runs
+      WHERE status = 'running'
+    )
+    UPDATE job_chat_runs
+    SET
+      status = 'failed',
+      error_code = COALESCE(error_code, 'CONFLICT'),
+      error_message = COALESCE(error_message, 'Recovered duplicate running run during migration'),
+      completed_at = COALESCE(completed_at, CAST(strftime('%s', 'now') AS INTEGER) * 1000),
+      updated_at = datetime('now')
+    WHERE id IN (SELECT id FROM ranked WHERE rank_in_thread > 1)`,
+  `CREATE UNIQUE INDEX IF NOT EXISTS idx_job_chat_runs_thread_running_unique
+   ON job_chat_runs(thread_id)
+   WHERE status = 'running'`,
 
   // Backfill: Create "Applied" events for legacy jobs that have applied_at set but no event entry
   `INSERT INTO stage_events (id, application_id, title, from_stage, to_stage, occurred_at, metadata)
diff --git a/orchestrator/src/server/db/schema.ts b/orchestrator/src/server/db/schema.ts
index 01dce0d..4d2c6f7 100644
--- a/orchestrator/src/server/db/schema.ts
+++ b/orchestrator/src/server/db/schema.ts
@@ -8,6 +8,9 @@ import {
   APPLICATION_TASK_TYPES,
   INTERVIEW_OUTCOMES,
   INTERVIEW_TYPES,
+  JOB_CHAT_MESSAGE_ROLES,
+  JOB_CHAT_MESSAGE_STATUSES,
+  JOB_CHAT_RUN_STATUSES,
   POST_APPLICATION_INTEGRATION_STATUSES,
   POST_APPLICATION_MESSAGE_TYPES,
   POST_APPLICATION_PROCESSING_STATUSES,
@@ -170,6 +173,87 @@ export const pipelineRuns = sqliteTable("pipeline_runs", {
   errorMessage: text("error_message"),
 });
 
+export const jobChatThreads = sqliteTable(
+  "job_chat_threads",
+  {
+    id: text("id").primaryKey(),
+    jobId: text("job_id")
+      .notNull()
+      .references(() => jobs.id, { onDelete: "cascade" }),
+    title: text("title"),
+    createdAt: text("created_at").notNull().default(sql`(datetime('now'))`),
+    updatedAt: text("updated_at").notNull().default(sql`(datetime('now'))`),
+    lastMessageAt: text("last_message_at"),
+  },
+  (table) => ({
+    jobUpdatedIndex: index("idx_job_chat_threads_job_updated").on(
+      table.jobId,
+      table.updatedAt,
+    ),
+  }),
+);
+
+export const jobChatMessages = sqliteTable(
+  "job_chat_messages",
+  {
+    id: text("id").primaryKey(),
+    threadId: text("thread_id")
+      .notNull()
+      .references(() => jobChatThreads.id, { onDelete: "cascade" }),
+    jobId: text("job_id")
+      .notNull()
+      .references(() => jobs.id, { onDelete: "cascade" }),
+    role: text("role", { enum: JOB_CHAT_MESSAGE_ROLES }).notNull(),
+    content: text("content").notNull().default(""),
+    status: text("status", { enum: JOB_CHAT_MESSAGE_STATUSES })
+      .notNull()
+      .default("partial"),
+    tokensIn: integer("tokens_in"),
+    tokensOut: integer("tokens_out"),
+    version: integer("version").notNull().default(1),
+    replacesMessageId: text("replaces_message_id"),
+    createdAt: text("created_at").notNull().default(sql`(datetime('now'))`),
+    updatedAt: text("updated_at").notNull().default(sql`(datetime('now'))`),
+  },
+  (table) => ({
+    threadCreatedIndex: index("idx_job_chat_messages_thread_created").on(
+      table.threadId,
+      table.createdAt,
+    ),
+  }),
+);
+
+export const jobChatRuns = sqliteTable(
+  "job_chat_runs",
+  {
+    id: text("id").primaryKey(),
+    threadId: text("thread_id")
+      .notNull()
+      .references(() => jobChatThreads.id, { onDelete: "cascade" }),
+    jobId: text("job_id")
+      .notNull()
+      .references(() => jobs.id, { onDelete: "cascade" }),
+    status: text("status", { enum: JOB_CHAT_RUN_STATUSES })
+      .notNull()
+      .default("running"),
+    model: text("model"),
+    provider: text("provider"),
+    errorCode: text("error_code"),
+    errorMessage: text("error_message"),
+    startedAt: integer("started_at", { mode: "number" }).notNull(),
+    completedAt: integer("completed_at", { mode: "number" }),
+    requestId: text("request_id"),
+    createdAt: text("created_at").notNull().default(sql`(datetime('now'))`),
+    updatedAt: text("updated_at").notNull().default(sql`(datetime('now'))`),
+  },
+  (table) => ({
+    threadStatusIndex: index("idx_job_chat_runs_thread_status").on(
+      table.threadId,
+      table.status,
+    ),
+  }),
+);
+
 export const settings = sqliteTable("settings", {
   key: text("key").primaryKey(),
   value: text("value").notNull(),
@@ -310,6 +394,12 @@ export type InterviewRow = typeof interviews.$inferSelect;
 export type NewInterviewRow = typeof interviews.$inferInsert;
 export type PipelineRunRow = typeof pipelineRuns.$inferSelect;
 export type NewPipelineRunRow = typeof pipelineRuns.$inferInsert;
+export type JobChatThreadRow = typeof jobChatThreads.$inferSelect;
+export type NewJobChatThreadRow = typeof jobChatThreads.$inferInsert;
+export type JobChatMessageRow = typeof jobChatMessages.$inferSelect;
+export type NewJobChatMessageRow = typeof jobChatMessages.$inferInsert;
+export type JobChatRunRow = typeof jobChatRuns.$inferSelect;
+export type NewJobChatRunRow = typeof jobChatRuns.$inferInsert;
 export type SettingsRow = typeof settings.$inferSelect;
 export type NewSettingsRow = typeof settings.$inferInsert;
 export type PostApplicationIntegrationRow =
diff --git a/orchestrator/src/server/repositories/ghostwriter.ts b/orchestrator/src/server/repositories/ghostwriter.ts
new file mode 100644
index 0000000..fec863d
--- /dev/null
+++ b/orchestrator/src/server/repositories/ghostwriter.ts
@@ -0,0 +1,368 @@
+import { randomUUID } from "node:crypto";
+import type {
+  JobChatMessage,
+  JobChatMessageRole,
+  JobChatMessageStatus,
+  JobChatRun,
+  JobChatRunStatus,
+  JobChatThread,
+} from "@shared/types";
+import { and, desc, eq } from "drizzle-orm";
+import { db, schema } from "../db";
+
+const { jobChatMessages, jobChatRuns, jobChatThreads } = schema;
+
+function mapThread(row: typeof jobChatThreads.$inferSelect): JobChatThread {
+  return {
+    id: row.id,
+    jobId: row.jobId,
+    title: row.title,
+    createdAt: row.createdAt,
+    updatedAt: row.updatedAt,
+    lastMessageAt: row.lastMessageAt,
+  };
+}
+
+function mapMessage(row: typeof jobChatMessages.$inferSelect): JobChatMessage {
+  return {
+    id: row.id,
+    threadId: row.threadId,
+    jobId: row.jobId,
+    role: row.role as JobChatMessageRole,
+    content: row.content,
+    status: row.status as JobChatMessageStatus,
+    tokensIn: row.tokensIn,
+    tokensOut: row.tokensOut,
+    version: row.version,
+    replacesMessageId: row.replacesMessageId,
+    createdAt: row.createdAt,
+    updatedAt: row.updatedAt,
+  };
+}
+
+function mapRun(row: typeof jobChatRuns.$inferSelect): JobChatRun {
+  return {
+    id: row.id,
+    threadId: row.threadId,
+    jobId: row.jobId,
+    status: row.status as JobChatRunStatus,
+    model: row.model,
+    provider: row.provider,
+    errorCode: row.errorCode,
+    errorMessage: row.errorMessage,
+    startedAt: row.startedAt,
+    completedAt: row.completedAt,
+    requestId: row.requestId,
+    createdAt: row.createdAt,
+    updatedAt: row.updatedAt,
+  };
+}
+
+export async function listThreadsForJob(
+  jobId: string,
+): Promise<JobChatThread[]> {
+  const rows = await db
+    .select()
+    .from(jobChatThreads)
+    .where(eq(jobChatThreads.jobId, jobId))
+    .orderBy(desc(jobChatThreads.updatedAt));
+
+  return rows.map(mapThread);
+}
+
+export async function getOrCreateThreadForJob(input: {
+  jobId: string;
+  title?: string | null;
+}): Promise<JobChatThread> {
+  const existing = await listThreadsForJob(input.jobId);
+  if (existing.length > 0) {
+    return existing[0];
+  }
+  return createThread({
+    jobId: input.jobId,
+    title: input.title ?? null,
+  });
+}
+
+export async function getThreadById(
+  threadId: string,
+): Promise<JobChatThread | null> {
+  const [row] = await db
+    .select()
+    .from(jobChatThreads)
+    .where(eq(jobChatThreads.id, threadId));
+  return row ? mapThread(row) : null;
+}
+
+export async function getThreadForJob(
+  jobId: string,
+  threadId: string,
+): Promise<JobChatThread | null> {
+  const [row] = await db
+    .select()
+    .from(jobChatThreads)
+    .where(
+      and(eq(jobChatThreads.id, threadId), eq(jobChatThreads.jobId, jobId)),
+    );
+  return row ? mapThread(row) : null;
+}
+
+export async function createThread(input: {
+  jobId: string;
+  title?: string | null;
+}): Promise<JobChatThread> {
+  const id = randomUUID();
+  const now = new Date().toISOString();
+
+  await db.insert(jobChatThreads).values({
+    id,
+    jobId: input.jobId,
+    title: input.title ?? null,
+    createdAt: now,
+    updatedAt: now,
+    lastMessageAt: null,
+  });
+
+  const thread = await getThreadById(id);
+  if (!thread) {
+    throw new Error(`Failed to load created chat thread ${id}.`);
+  }
+  return thread;
+}
+
+export async function touchThread(
+  threadId: string,
+  lastMessageAt?: string,
+): Promise<void> {
+  const now = new Date().toISOString();
+  await db
+    .update(jobChatThreads)
+    .set({
+      updatedAt: now,
+      ...(lastMessageAt !== undefined ? { lastMessageAt } : {}),
+    })
+    .where(eq(jobChatThreads.id, threadId));
+}
+
+export async function listMessagesForThread(
+  threadId: string,
+  options?: { limit?: number; offset?: number },
+): Promise<JobChatMessage[]> {
+  const limit = options?.limit ?? 200;
+  const offset = options?.offset ?? 0;
+
+  const rows = await db
+    .select()
+    .from(jobChatMessages)
+    .where(eq(jobChatMessages.threadId, threadId))
+    .orderBy(jobChatMessages.createdAt)
+    .limit(limit)
+    .offset(offset);
+
+  return rows.map(mapMessage);
+}
+
+export async function getMessageById(
+  messageId: string,
+): Promise<JobChatMessage | null> {
+  const [row] = await db
+    .select()
+    .from(jobChatMessages)
+    .where(eq(jobChatMessages.id, messageId));
+  return row ? mapMessage(row) : null;
+}
+
+export async function createMessage(input: {
+  threadId: string;
+  jobId: string;
+  role: JobChatMessageRole;
+  content: string;
+  status?: JobChatMessageStatus;
+  tokensIn?: number | null;
+  tokensOut?: number | null;
+  version?: number;
+  replacesMessageId?: string | null;
+}): Promise<JobChatMessage> {
+  const id = randomUUID();
+  const now = new Date().toISOString();
+
+  await db.insert(jobChatMessages).values({
+    id,
+    threadId: input.threadId,
+    jobId: input.jobId,
+    role: input.role,
+    content: input.content,
+    status: input.status ?? "partial",
+    tokensIn: input.tokensIn ?? null,
+    tokensOut: input.tokensOut ?? null,
+    version: input.version ?? 1,
+    replacesMessageId: input.replacesMessageId ?? null,
+    createdAt: now,
+    updatedAt: now,
+  });
+
+  await touchThread(input.threadId, now);
+
+  const created = await getMessageById(id);
+  if (!created) {
+    throw new Error(`Failed to load created chat message ${id}.`);
+  }
+  return created;
+}
+
+export async function updateMessage(
+  messageId: string,
+  input: {
+    content?: string;
+    status?: JobChatMessageStatus;
+    tokensIn?: number | null;
+    tokensOut?: number | null;
+  },
+): Promise<JobChatMessage | null> {
+  const now = new Date().toISOString();
+
+  await db
+    .update(jobChatMessages)
+    .set({
+      ...(input.content !== undefined ? { content: input.content } : {}),
+      ...(input.status !== undefined ? { status: input.status } : {}),
+      ...(input.tokensIn !== undefined ? { tokensIn: input.tokensIn } : {}),
+      ...(input.tokensOut !== undefined ? { tokensOut: input.tokensOut } : {}),
+      updatedAt: now,
+    })
+    .where(eq(jobChatMessages.id, messageId));
+
+  const message = await getMessageById(messageId);
+  if (message) {
+    await touchThread(message.threadId, now);
+  }
+  return message;
+}
+
+export async function getLatestAssistantMessage(
+  threadId: string,
+): Promise<JobChatMessage | null> {
+  const [row] = await db
+    .select()
+    .from(jobChatMessages)
+    .where(
+      and(
+        eq(jobChatMessages.threadId, threadId),
+        eq(jobChatMessages.role, "assistant"),
+      ),
+    )
+    .orderBy(desc(jobChatMessages.createdAt))
+    .limit(1);
+
+  return row ? mapMessage(row) : null;
+}
+
+export async function createRun(input: {
+  threadId: string;
+  jobId: string;
+  model: string | null;
+  provider: string | null;
+  requestId?: string | null;
+}): Promise<JobChatRun> {
+  const id = randomUUID();
+  const startedAt = Date.now();
+  const now = new Date(startedAt).toISOString();
+
+  await db.insert(jobChatRuns).values({
+    id,
+    threadId: input.threadId,
+    jobId: input.jobId,
+    status: "running",
+    model: input.model,
+    provider: input.provider,
+    errorCode: null,
+    errorMessage: null,
+    startedAt,
+    completedAt: null,
+    requestId: input.requestId ?? null,
+    createdAt: now,
+    updatedAt: now,
+  });
+
+  const run = await getRunById(id);
+  if (!run) {
+    throw new Error(`Failed to load created chat run ${id}.`);
+  }
+  return run;
+}
+
+export async function getRunById(runId: string): Promise<JobChatRun | null> {
+  const [row] = await db
+    .select()
+    .from(jobChatRuns)
+    .where(eq(jobChatRuns.id, runId));
+  return row ? mapRun(row) : null;
+}
+
+export async function getActiveRunForThread(
+  threadId: string,
+): Promise<JobChatRun | null> {
+  const [row] = await db
+    .select()
+    .from(jobChatRuns)
+    .where(
+      and(
+        eq(jobChatRuns.threadId, threadId),
+        eq(jobChatRuns.status, "running"),
+      ),
+    )
+    .orderBy(desc(jobChatRuns.startedAt))
+    .limit(1);
+
+  return row ? mapRun(row) : null;
+}
+
+export async function completeRun(
+  runId: string,
+  input: {
+    status: Exclude<JobChatRunStatus, "running">;
+    errorCode?: string | null;
+    errorMessage?: string | null;
+  },
+): Promise<JobChatRun | null> {
+  const nowEpoch = Date.now();
+  const nowIso = new Date(nowEpoch).toISOString();
+
+  await db
+    .update(jobChatRuns)
+    .set({
+      status: input.status,
+      completedAt: nowEpoch,
+      errorCode: input.errorCode ?? null,
+      errorMessage: input.errorMessage ?? null,
+      updatedAt: nowIso,
+    })
+    .where(eq(jobChatRuns.id, runId));
+
+  return getRunById(runId);
+}
+
+export async function completeRunIfRunning(
+  runId: string,
+  input: {
+    status: Exclude<JobChatRunStatus, "running">;
+    errorCode?: string | null;
+    errorMessage?: string | null;
+  },
+): Promise<JobChatRun | null> {
+  const nowEpoch = Date.now();
+  const nowIso = new Date(nowEpoch).toISOString();
+
+  await db
+    .update(jobChatRuns)
+    .set({
+      status: input.status,
+      completedAt: nowEpoch,
+      errorCode: input.errorCode ?? null,
+      errorMessage: input.errorMessage ?? null,
+      updatedAt: nowIso,
+    })
+    .where(and(eq(jobChatRuns.id, runId), eq(jobChatRuns.status, "running")));
+
+  return getRunById(runId);
+}
diff --git a/orchestrator/src/server/repositories/settings.ts b/orchestrator/src/server/repositories/settings.ts
index d9571de..40c2774 100644
--- a/orchestrator/src/server/repositories/settings.ts
+++ b/orchestrator/src/server/repositories/settings.ts
@@ -26,6 +26,10 @@ export type SettingKey =
   | "jobspyResultsWanted"
   | "jobspyCountryIndeed"
   | "showSponsorInfo"
+  | "chatStyleTone"
+  | "chatStyleFormality"
+  | "chatStyleConstraints"
+  | "chatStyleDoNotUse"
   | "rxresumeEmail"
   | "rxresumePassword"
   | "basicAuthUser"
diff --git a/orchestrator/src/server/services/ghostwriter-context.test.ts b/orchestrator/src/server/services/ghostwriter-context.test.ts
new file mode 100644
index 0000000..b9daa01
--- /dev/null
+++ b/orchestrator/src/server/services/ghostwriter-context.test.ts
@@ -0,0 +1,126 @@
+import { createJob } from "@shared/testing/factories";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import type { AppError } from "../infra/errors";
+import { buildJobChatPromptContext } from "./ghostwriter-context";
+
+vi.mock("../repositories/jobs", () => ({
+  getJobById: vi.fn(),
+}));
+
+vi.mock("../repositories/settings", () => ({
+  getAllSettings: vi.fn(),
+}));
+
+vi.mock("./profile", () => ({
+  getProfile: vi.fn(),
+}));
+
+vi.mock("./settings-conversion", () => ({
+  resolveSettingValue: vi.fn(),
+}));
+
+import { getJobById } from "../repositories/jobs";
+import { getAllSettings } from "../repositories/settings";
+import { getProfile } from "./profile";
+import { resolveSettingValue } from "./settings-conversion";
+
+describe("buildJobChatPromptContext", () => {
+  beforeEach(() => {
+    vi.resetAllMocks();
+    vi.mocked(getAllSettings).mockResolvedValue({});
+    vi.mocked(resolveSettingValue).mockImplementation((key, override) => {
+      const fallback: Record<string, string> = {
+        chatStyleTone: "professional",
+        chatStyleFormality: "medium",
+        chatStyleConstraints: "",
+        chatStyleDoNotUse: "",
+      };
+      return { value: override ?? fallback[key as string] ?? "" } as any;
+    });
+  });
+
+  it("builds context with style directives and snapshots", async () => {
+    const job = createJob({
+      id: "job-ctx-1",
+      title: "Software Engineer",
+      employer: "JP Morgan",
+      jobDescription: "A".repeat(5000),
+    });
+
+    vi.mocked(getJobById).mockResolvedValue(job);
+    vi.mocked(getAllSettings).mockResolvedValue({
+      chatStyleTone: "direct",
+      chatStyleFormality: "high",
+      chatStyleConstraints: "Keep responses under 120 words",
+      chatStyleDoNotUse: "synergy, leverage",
+    });
+    vi.mocked(getProfile).mockResolvedValue({
+      basics: {
+        name: "Test User",
+        headline: "Full-stack engineer",
+        summary: "I build production systems",
+      },
+      sections: {
+        skills: {
+          name: "Skills",
+          visible: true,
+          id: "skills-1",
+          items: [
+            {
+              id: "skill-1",
+              visible: true,
+              name: "TypeScript",
+              description: "",
+              level: 4,
+              keywords: ["Node.js", "React"],
+            },
+          ],
+        },
+      },
+    });
+
+    const context = await buildJobChatPromptContext(job.id);
+
+    expect(context.style).toEqual({
+      tone: "direct",
+      formality: "high",
+      constraints: "Keep responses under 120 words",
+      doNotUse: "synergy, leverage",
+    });
+    expect(context.systemPrompt).toContain("Writing style tone: direct.");
+    expect(context.systemPrompt).toContain("Writing style formality: high.");
+    expect(context.systemPrompt).toContain(
+      "Writing constraints: Keep responses under 120 words",
+    );
+    expect(context.systemPrompt).toContain(
+      "Avoid these terms: synergy, leverage",
+    );
+    expect(context.jobSnapshot).toContain('"id": "job-ctx-1"');
+    expect(context.jobSnapshot.length).toBeLessThan(6000);
+    expect(context.profileSnapshot).toContain("Name: Test User");
+    expect(context.profileSnapshot).toContain("Skills:");
+  });
+
+  it("falls back to empty profile snapshot when profile loading fails", async () => {
+    const job = createJob({ id: "job-ctx-2" });
+    vi.mocked(getJobById).mockResolvedValue(job);
+    vi.mocked(getProfile).mockRejectedValue(new Error("profile unavailable"));
+
+    const context = await buildJobChatPromptContext(job.id);
+
+    expect(context.job.id).toBe("job-ctx-2");
+    expect(context.profileSnapshot).toContain("Name: Unknown");
+    expect(context.systemPrompt).toContain("Writing style tone: professional.");
+  });
+
+  it("throws not found for unknown job", async () => {
+    vi.mocked(getJobById).mockResolvedValue(null);
+
+    await expect(
+      buildJobChatPromptContext("missing-job"),
+    ).rejects.toMatchObject({
+      code: "NOT_FOUND",
+      status: 404,
+    } satisfies Partial<AppError>);
+  });
+});
diff --git a/orchestrator/src/server/services/ghostwriter-context.ts b/orchestrator/src/server/services/ghostwriter-context.ts
new file mode 100644
index 0000000..31df771
--- /dev/null
+++ b/orchestrator/src/server/services/ghostwriter-context.ts
@@ -0,0 +1,193 @@
+import { logger } from "@infra/logger";
+import { sanitizeUnknown } from "@infra/sanitize";
+import type { Job, ResumeProfile } from "@shared/types";
+import { badRequest, notFound } from "../infra/errors";
+import * as jobsRepo from "../repositories/jobs";
+import * as settingsRepo from "../repositories/settings";
+import { getProfile } from "./profile";
+import { resolveSettingValue } from "./settings-conversion";
+
+type JobChatStyle = {
+  tone: string;
+  formality: string;
+  constraints: string;
+  doNotUse: string;
+};
+
+export type JobChatPromptContext = {
+  job: Job;
+  style: JobChatStyle;
+  systemPrompt: string;
+  jobSnapshot: string;
+  profileSnapshot: string;
+};
+
+const MAX_JOB_DESCRIPTION = 4000;
+const MAX_PROFILE_SUMMARY = 1200;
+const MAX_SKILLS = 18;
+const MAX_PROJECTS = 6;
+const MAX_EXPERIENCE = 5;
+const MAX_ITEM_TEXT = 320;
+
+function truncate(value: string | null | undefined, max: number): string {
+  if (!value) return "";
+  const trimmed = value.trim();
+  if (trimmed.length <= max) return trimmed;
+  return `${trimmed.slice(0, max)}...`;
+}
+
+function compactJoin(parts: Array<string | null | undefined>): string {
+  return parts.filter(Boolean).join("\n");
+}
+
+function buildJobSnapshot(job: Job): string {
+  const snapshot = {
+    event: "job.completed",
+    sentAt: new Date().toISOString(),
+    job: {
+      id: job.id,
+      source: job.source,
+      title: job.title,
+      employer: job.employer,
+      location: job.location,
+      salary: job.salary,
+      status: job.status,
+      jobUrl: job.jobUrl,
+      applicationLink: job.applicationLink,
+      suitabilityScore: job.suitabilityScore,
+      suitabilityReason: truncate(job.suitabilityReason, 600),
+      tailoredSummary: truncate(job.tailoredSummary, 1200),
+      tailoredHeadline: truncate(job.tailoredHeadline, 300),
+      tailoredSkills: truncate(job.tailoredSkills, 1200),
+      jobDescription: truncate(job.jobDescription, MAX_JOB_DESCRIPTION),
+    },
+  };
+
+  return JSON.stringify(snapshot, null, 2);
+}
+
+function buildProfileSnapshot(profile: ResumeProfile): string {
+  const summary =
+    truncate(profile?.sections?.summary?.content, MAX_PROFILE_SUMMARY) ||
+    truncate(profile?.basics?.summary, MAX_PROFILE_SUMMARY);
+
+  const skills = (profile?.sections?.skills?.items ?? [])
+    .slice(0, MAX_SKILLS)
+    .map((item) => {
+      const keywords = (item.keywords ?? []).slice(0, 8).join(", ");
+      return `${item.name}${keywords ? `: ${keywords}` : ""}`;
+    });
+
+  const projects = (profile?.sections?.projects?.items ?? [])
+    .filter((item) => item.visible !== false)
+    .slice(0, MAX_PROJECTS)
+    .map(
+      (item) =>
+        `${item.name} (${item.date || "n/a"}): ${truncate(item.summary, MAX_ITEM_TEXT)}`,
+    );
+
+  const experience = (profile?.sections?.experience?.items ?? [])
+    .filter((item) => item.visible !== false)
+    .slice(0, MAX_EXPERIENCE)
+    .map(
+      (item) =>
+        `${item.position} @ ${item.company} (${item.date || "n/a"}): ${truncate(item.summary, MAX_ITEM_TEXT)}`,
+    );
+
+  return compactJoin([
+    `Name: ${profile?.basics?.name || "Unknown"}`,
+    `Headline: ${truncate(profile?.basics?.headline || profile?.basics?.label, 200) || ""}`,
+    summary ? `Summary:\n${summary}` : null,
+    skills.length > 0 ? `Skills:\n- ${skills.join("\n- ")}` : null,
+    projects.length > 0 ? `Projects:\n- ${projects.join("\n- ")}` : null,
+    experience.length > 0 ? `Experience:\n- ${experience.join("\n- ")}` : null,
+  ]);
+}
+
+function buildSystemPrompt(style: JobChatStyle): string {
+  return compactJoin([
+    "You are Ghostwriter, a job-application writing assistant for a single job.",
+    "Use only the provided job and profile context unless the user gives extra details.",
+    "Do not claim actions were executed. You are read-only and advisory.",
+    "If details are missing, say what is missing before making assumptions.",
+    "Avoid exposing private profile details that are unrelated to the user request.",
+    `Writing style tone: ${style.tone}.`,
+    `Writing style formality: ${style.formality}.`,
+    style.constraints ? `Writing constraints: ${style.constraints}` : null,
+    style.doNotUse ? `Avoid these terms: ${style.doNotUse}` : null,
+  ]);
+}
+
+async function resolveStyle(): Promise<JobChatStyle> {
+  const overrides = await settingsRepo.getAllSettings();
+  const tone = resolveSettingValue(
+    "chatStyleTone",
+    overrides.chatStyleTone,
+  ).value;
+  const formality = resolveSettingValue(
+    "chatStyleFormality",
+    overrides.chatStyleFormality,
+  ).value;
+  const constraints = resolveSettingValue(
+    "chatStyleConstraints",
+    overrides.chatStyleConstraints,
+  ).value;
+  const doNotUse = resolveSettingValue(
+    "chatStyleDoNotUse",
+    overrides.chatStyleDoNotUse,
+  ).value;
+
+  return {
+    tone,
+    formality,
+    constraints,
+    doNotUse,
+  };
+}
+
+export async function buildJobChatPromptContext(
+  jobId: string,
+): Promise<JobChatPromptContext> {
+  const job = await jobsRepo.getJobById(jobId);
+  if (!job) {
+    throw notFound("Job not found");
+  }
+
+  const style = await resolveStyle();
+
+  let profile: ResumeProfile = {};
+  try {
+    profile = await getProfile();
+  } catch (error) {
+    logger.warn("Failed to load profile for job chat context", {
+      jobId,
+      error: sanitizeUnknown(error),
+    });
+  }
+
+  const systemPrompt = buildSystemPrompt(style);
+  const jobSnapshot = buildJobSnapshot(job);
+  const profileSnapshot = buildProfileSnapshot(profile);
+
+  if (!jobSnapshot.trim()) {
+    throw badRequest("Unable to build job context");
+  }
+
+  logger.info("Built job chat context", {
+    jobId,
+    includesProfile: Boolean(profileSnapshot),
+    contextStats: sanitizeUnknown({
+      systemChars: systemPrompt.length,
+      jobChars: jobSnapshot.length,
+      profileChars: profileSnapshot.length,
+    }),
+  });
+
+  return {
+    job,
+    style,
+    systemPrompt,
+    jobSnapshot,
+    profileSnapshot,
+  };
+}
diff --git a/orchestrator/src/server/services/ghostwriter.test.ts b/orchestrator/src/server/services/ghostwriter.test.ts
new file mode 100644
index 0000000..ce72032
--- /dev/null
+++ b/orchestrator/src/server/services/ghostwriter.test.ts
@@ -0,0 +1,528 @@
+import type { JobChatMessage } from "@shared/types";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+const mocks = vi.hoisted(() => ({
+  getRequestId: vi.fn(),
+  buildJobChatPromptContext: vi.fn(),
+  llmCallJson: vi.fn(),
+  repo: {
+    getOrCreateThreadForJob: vi.fn(),
+    getThreadForJob: vi.fn(),
+    listMessagesForThread: vi.fn(),
+    getActiveRunForThread: vi.fn(),
+    createMessage: vi.fn(),
+    createRun: vi.fn(),
+    updateMessage: vi.fn(),
+    completeRun: vi.fn(),
+    completeRunIfRunning: vi.fn(),
+    getMessageById: vi.fn(),
+    getLatestAssistantMessage: vi.fn(),
+    getRunById: vi.fn(),
+  },
+  settings: {
+    getAllSettings: vi.fn(),
+  },
+}));
+
+vi.mock("@infra/logger", () => ({
+  logger: {
+    info: vi.fn(),
+    warn: vi.fn(),
+    error: vi.fn(),
+  },
+}));
+
+vi.mock("@infra/request-context", () => ({
+  getRequestId: mocks.getRequestId,
+}));
+
+vi.mock("./ghostwriter-context", () => ({
+  buildJobChatPromptContext: mocks.buildJobChatPromptContext,
+}));
+
+vi.mock("../repositories/settings", () => ({
+  getAllSettings: mocks.settings.getAllSettings,
+}));
+
+vi.mock("../repositories/ghostwriter", () => ({
+  getOrCreateThreadForJob: mocks.repo.getOrCreateThreadForJob,
+  getThreadForJob: mocks.repo.getThreadForJob,
+  listMessagesForThread: mocks.repo.listMessagesForThread,
+  getActiveRunForThread: mocks.repo.getActiveRunForThread,
+  createMessage: mocks.repo.createMessage,
+  createRun: mocks.repo.createRun,
+  updateMessage: mocks.repo.updateMessage,
+  completeRun: mocks.repo.completeRun,
+  completeRunIfRunning: mocks.repo.completeRunIfRunning,
+  getMessageById: mocks.repo.getMessageById,
+  getLatestAssistantMessage: mocks.repo.getLatestAssistantMessage,
+  getRunById: mocks.repo.getRunById,
+}));
+
+vi.mock("./llm/service", () => ({
+  LlmService: class {
+    callJson = mocks.llmCallJson;
+  },
+}));
+
+import {
+  cancelRun,
+  cancelRunForJob,
+  createThread,
+  regenerateMessage,
+  sendMessage,
+  sendMessageForJob,
+} from "./ghostwriter";
+
+const thread = {
+  id: "thread-1",
+  jobId: "job-1",
+  title: null,
+  createdAt: new Date().toISOString(),
+  updatedAt: new Date().toISOString(),
+  lastMessageAt: null,
+};
+
+const baseUserMessage: JobChatMessage = {
+  id: "user-1",
+  threadId: "thread-1",
+  jobId: "job-1",
+  role: "user",
+  content: "Tell me about this role",
+  status: "complete",
+  tokensIn: 6,
+  tokensOut: null,
+  version: 1,
+  replacesMessageId: null,
+  createdAt: new Date().toISOString(),
+  updatedAt: new Date().toISOString(),
+};
+
+const baseAssistantMessage: JobChatMessage = {
+  id: "assistant-1",
+  threadId: "thread-1",
+  jobId: "job-1",
+  role: "assistant",
+  content: "Draft response",
+  status: "complete",
+  tokensIn: 6,
+  tokensOut: 4,
+  version: 1,
+  replacesMessageId: null,
+  createdAt: new Date().toISOString(),
+  updatedAt: new Date().toISOString(),
+};
+
+describe("ghostwriter service", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+
+    mocks.getRequestId.mockReturnValue("req-123");
+    mocks.settings.getAllSettings.mockResolvedValue({});
+    mocks.buildJobChatPromptContext.mockResolvedValue({
+      job: { id: "job-1" },
+      style: {
+        tone: "professional",
+        formality: "medium",
+        constraints: "",
+        doNotUse: "",
+      },
+      systemPrompt: "system prompt",
+      jobSnapshot: '{"job":"snapshot"}',
+      profileSnapshot: "profile snapshot",
+    });
+
+    mocks.repo.getOrCreateThreadForJob.mockResolvedValue(thread);
+    mocks.repo.getThreadForJob.mockResolvedValue(thread);
+    mocks.repo.getActiveRunForThread.mockResolvedValue(null);
+    mocks.repo.createRun.mockResolvedValue({
+      id: "run-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "running",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: null,
+      errorMessage: null,
+      startedAt: Date.now(),
+      completedAt: null,
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
+    mocks.repo.completeRun.mockResolvedValue(null);
+    mocks.repo.completeRunIfRunning.mockResolvedValue({
+      id: "run-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "completed",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: null,
+      errorMessage: null,
+      startedAt: Date.now(),
+      completedAt: Date.now(),
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
+    mocks.repo.updateMessage.mockResolvedValue(baseAssistantMessage);
+    mocks.repo.getMessageById.mockResolvedValue(baseAssistantMessage);
+    mocks.repo.listMessagesForThread.mockResolvedValue([
+      baseUserMessage,
+      baseAssistantMessage,
+      {
+        ...baseAssistantMessage,
+        id: "tool-1",
+        role: "tool",
+      },
+      {
+        ...baseAssistantMessage,
+        id: "failed-1",
+        role: "assistant",
+        status: "failed",
+      },
+    ]);
+    mocks.llmCallJson.mockResolvedValue({
+      success: true,
+      data: { response: "Thanks for your question." },
+    });
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("sends message, runs LLM, and returns user + assistant messages", async () => {
+    const assistantPartial: JobChatMessage = {
+      ...baseAssistantMessage,
+      id: "assistant-partial",
+      content: "",
+      status: "partial",
+    };
+    const assistantComplete: JobChatMessage = {
+      ...baseAssistantMessage,
+      id: "assistant-partial",
+      content: "Thanks for your question.",
+      status: "complete",
+      tokensOut: 7,
+    };
+
+    mocks.repo.createMessage
+      .mockResolvedValueOnce(baseUserMessage)
+      .mockResolvedValueOnce(assistantPartial);
+    mocks.repo.updateMessage.mockResolvedValue(assistantComplete);
+    mocks.repo.getMessageById.mockResolvedValue(assistantComplete);
+
+    const result = await sendMessageForJob({
+      jobId: "job-1",
+      content: "  Tell me about this role  ",
+    });
+
+    expect(result.runId).toBe("run-1");
+    expect(result.userMessage.role).toBe("user");
+    expect(result.assistantMessage?.role).toBe("assistant");
+    expect(mocks.repo.createRun).toHaveBeenCalledWith(
+      expect.objectContaining({
+        requestId: "req-123",
+      }),
+    );
+
+    const llmArg = mocks.llmCallJson.mock.calls[0][0];
+    expect(llmArg.messages.at(-1)).toMatchObject({
+      role: "user",
+      content: "Tell me about this role",
+    });
+    expect(
+      llmArg.messages.filter(
+        (message: { role: string }) =>
+          message.role !== "system" && message.role !== "user",
+      ),
+    ).toEqual([{ role: "assistant", content: "Draft response" }]);
+  });
+
+  it("passes title when creating the first thread", async () => {
+    await createThread({
+      jobId: "job-1",
+      title: "Initial thread title",
+    });
+
+    expect(mocks.repo.getOrCreateThreadForJob).toHaveBeenCalledWith({
+      jobId: "job-1",
+      title: "Initial thread title",
+    });
+  });
+
+  it("rejects empty message content", async () => {
+    await expect(
+      sendMessage({
+        jobId: "job-1",
+        threadId: "thread-1",
+        content: "   ",
+      }),
+    ).rejects.toMatchObject({
+      code: "INVALID_REQUEST",
+      status: 400,
+    });
+  });
+
+  it("cancels a running generation during streaming", async () => {
+    vi.useFakeTimers();
+
+    const assistantPartial: JobChatMessage = {
+      ...baseAssistantMessage,
+      id: "assistant-stream",
+      content: "",
+      status: "partial",
+    };
+    const assistantCancelled: JobChatMessage = {
+      ...assistantPartial,
+      status: "cancelled",
+      content: "",
+    };
+    let cancelPromise: Promise<{
+      cancelled: boolean;
+      alreadyFinished: boolean;
+    }> | null = null;
+
+    mocks.repo.createMessage
+      .mockResolvedValueOnce(baseUserMessage)
+      .mockResolvedValueOnce(assistantPartial);
+    mocks.repo.updateMessage.mockResolvedValue(assistantCancelled);
+    mocks.repo.getMessageById.mockResolvedValue(assistantCancelled);
+    mocks.repo.getRunById.mockResolvedValue({
+      id: "run-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "running",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: null,
+      errorMessage: null,
+      startedAt: Date.now(),
+      completedAt: null,
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
+    mocks.repo.completeRunIfRunning.mockResolvedValue({
+      id: "run-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "cancelled",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: "REQUEST_TIMEOUT",
+      errorMessage: "Generation cancelled by user",
+      startedAt: Date.now(),
+      completedAt: Date.now(),
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
+    mocks.llmCallJson.mockImplementation(async () => {
+      await vi.advanceTimersByTimeAsync(1);
+      return {
+        success: true,
+        data: { response: "x".repeat(200) },
+      };
+    });
+
+    const onReady = vi.fn(({ runId }: { runId: string }) => {
+      cancelPromise = cancelRunForJob({ jobId: "job-1", runId });
+    });
+    const onCancelled = vi.fn();
+    const onCompleted = vi.fn();
+
+    const resultPromise = sendMessageForJob({
+      jobId: "job-1",
+      content: "Cancel this",
+      stream: {
+        onReady,
+        onDelta: vi.fn(),
+        onCompleted,
+        onCancelled,
+        onError: vi.fn(),
+      },
+    });
+
+    await vi.runAllTimersAsync();
+    const result = await resultPromise;
+    await cancelPromise;
+
+    expect(onReady).toHaveBeenCalled();
+    expect(onCancelled).toHaveBeenCalled();
+    expect(onCompleted).not.toHaveBeenCalled();
+    expect(result.assistantMessage?.status).toBe("cancelled");
+  });
+
+  it("keeps cancellation when completion races at finish", async () => {
+    const assistantPartial: JobChatMessage = {
+      ...baseAssistantMessage,
+      id: "assistant-race",
+      content: "",
+      status: "partial",
+    };
+    const assistantComplete: JobChatMessage = {
+      ...assistantPartial,
+      content: "Thanks for your question.",
+      status: "complete",
+      tokensOut: 7,
+    };
+    const assistantCancelled: JobChatMessage = {
+      ...assistantPartial,
+      content: "Thanks for your question.",
+      status: "cancelled",
+      tokensOut: 7,
+    };
+
+    mocks.repo.createMessage
+      .mockResolvedValueOnce(baseUserMessage)
+      .mockResolvedValueOnce(assistantPartial);
+    mocks.repo.updateMessage
+      .mockResolvedValueOnce(assistantComplete)
+      .mockResolvedValueOnce(assistantCancelled);
+    mocks.repo.getMessageById.mockResolvedValue(assistantCancelled);
+    mocks.repo.completeRunIfRunning.mockResolvedValueOnce({
+      id: "run-1",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "cancelled",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: "REQUEST_TIMEOUT",
+      errorMessage: "Generation cancelled by user",
+      startedAt: Date.now(),
+      completedAt: Date.now(),
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
+
+    const onCompleted = vi.fn();
+    const onCancelled = vi.fn();
+
+    const result = await sendMessageForJob({
+      jobId: "job-1",
+      content: "Tell me about this role",
+      stream: {
+        onReady: vi.fn(),
+        onDelta: vi.fn(),
+        onCompleted,
+        onCancelled,
+        onError: vi.fn(),
+      },
+    });
+
+    expect(onCompleted).not.toHaveBeenCalled();
+    expect(onCancelled).toHaveBeenCalledTimes(1);
+    expect(result.assistantMessage?.status).toBe("cancelled");
+  });
+
+  it("enforces regenerate only on latest assistant message", async () => {
+    mocks.repo.getMessageById.mockResolvedValue(baseAssistantMessage);
+    mocks.repo.getLatestAssistantMessage.mockResolvedValue({
+      ...baseAssistantMessage,
+      id: "assistant-latest",
+    });
+
+    await expect(
+      regenerateMessage({
+        jobId: "job-1",
+        threadId: "thread-1",
+        assistantMessageId: "assistant-1",
+      }),
+    ).rejects.toMatchObject({
+      code: "INVALID_REQUEST",
+      status: 400,
+    });
+  });
+
+  it("returns alreadyFinished when cancelling non-running run", async () => {
+    mocks.repo.getRunById.mockResolvedValue({
+      id: "run-finished",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "completed",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: null,
+      errorMessage: null,
+      startedAt: Date.now(),
+      completedAt: Date.now(),
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
+
+    const result = await cancelRun({
+      jobId: "job-1",
+      threadId: "thread-1",
+      runId: "run-finished",
+    });
+
+    expect(result).toEqual({ cancelled: false, alreadyFinished: true });
+    expect(mocks.repo.completeRun).not.toHaveBeenCalled();
+    expect(mocks.repo.completeRunIfRunning).not.toHaveBeenCalled();
+  });
+
+  it("returns alreadyFinished when run completes before cancel write", async () => {
+    mocks.repo.getRunById.mockResolvedValue({
+      id: "run-race",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "running",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: null,
+      errorMessage: null,
+      startedAt: Date.now(),
+      completedAt: null,
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
+    mocks.repo.completeRunIfRunning.mockResolvedValue({
+      id: "run-race",
+      threadId: "thread-1",
+      jobId: "job-1",
+      status: "completed",
+      model: "model-a",
+      provider: "openrouter",
+      errorCode: null,
+      errorMessage: null,
+      startedAt: Date.now(),
+      completedAt: Date.now(),
+      requestId: "req-123",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    });
+
+    const result = await cancelRun({
+      jobId: "job-1",
+      threadId: "thread-1",
+      runId: "run-race",
+    });
+
+    expect(result).toEqual({ cancelled: false, alreadyFinished: true });
+  });
+
+  it("maps createRun unique constraint races to conflict", async () => {
+    mocks.repo.createMessage.mockResolvedValue(baseUserMessage);
+    mocks.repo.createRun.mockRejectedValue(
+      new Error(
+        "UNIQUE constraint failed: job_chat_runs.thread_id (idx_job_chat_runs_thread_running_unique)",
+      ),
+    );
+
+    await expect(
+      sendMessageForJob({
+        jobId: "job-1",
+        content: "hello",
+      }),
+    ).rejects.toMatchObject({
+      code: "CONFLICT",
+      status: 409,
+    });
+  });
+});
diff --git a/orchestrator/src/server/services/ghostwriter.ts b/orchestrator/src/server/services/ghostwriter.ts
new file mode 100644
index 0000000..206bb8d
--- /dev/null
+++ b/orchestrator/src/server/services/ghostwriter.ts
@@ -0,0 +1,617 @@
+import { logger } from "@infra/logger";
+import { getRequestId } from "@infra/request-context";
+import type { JobChatMessage, JobChatRun } from "@shared/types";
+import {
+  badRequest,
+  conflict,
+  notFound,
+  requestTimeout,
+  upstreamError,
+} from "../infra/errors";
+import * as jobChatRepo from "../repositories/ghostwriter";
+import * as settingsRepo from "../repositories/settings";
+import { buildJobChatPromptContext } from "./ghostwriter-context";
+import { LlmService } from "./llm/service";
+import type { JsonSchemaDefinition } from "./llm/types";
+
+type LlmRuntimeSettings = {
+  model: string;
+  provider: string | null;
+  baseUrl: string | null;
+  apiKey: string | null;
+};
+
+const abortControllers = new Map<string, AbortController>();
+
+const CHAT_RESPONSE_SCHEMA: JsonSchemaDefinition = {
+  name: "job_chat_response",
+  schema: {
+    type: "object",
+    properties: {
+      response: {
+        type: "string",
+      },
+    },
+    required: ["response"],
+    additionalProperties: false,
+  },
+};
+
+function estimateTokenCount(value: string): number {
+  if (!value) return 0;
+  return Math.ceil(value.length / 4);
+}
+
+function chunkText(value: string, maxChunk = 60): string[] {
+  if (!value) return [];
+  const chunks: string[] = [];
+  let cursor = 0;
+  while (cursor < value.length) {
+    chunks.push(value.slice(cursor, cursor + maxChunk));
+    cursor += maxChunk;
+  }
+  return chunks;
+}
+
+function isRunningRunUniqueConstraintError(error: unknown): boolean {
+  const message = error instanceof Error ? error.message : String(error);
+  return (
+    message.includes("idx_job_chat_runs_thread_running_unique") ||
+    message.includes("UNIQUE constraint failed: job_chat_runs.thread_id")
+  );
+}
+
+async function resolveLlmRuntimeSettings(): Promise<LlmRuntimeSettings> {
+  const overrides = await settingsRepo.getAllSettings();
+
+  const model =
+    overrides.modelTailoring ||
+    overrides.model ||
+    process.env.MODEL ||
+    "google/gemini-3-flash-preview";
+
+  const provider =
+    overrides.llmProvider || process.env.LLM_PROVIDER || "openrouter";
+
+  const baseUrl = overrides.llmBaseUrl || process.env.LLM_BASE_URL || null;
+
+  const apiKey = overrides.llmApiKey || process.env.LLM_API_KEY || null;
+
+  return {
+    model,
+    provider,
+    baseUrl,
+    apiKey,
+  };
+}
+
+async function buildConversationMessages(
+  threadId: string,
+): Promise<Array<{ role: "user" | "assistant"; content: string }>> {
+  const messages = await jobChatRepo.listMessagesForThread(threadId, {
+    limit: 40,
+  });
+
+  return messages
+    .filter(
+      (message): message is typeof message & { role: "user" | "assistant" } =>
+        message.role === "user" || message.role === "assistant",
+    )
+    .filter((message) => message.status !== "failed")
+    .map((message) => ({
+      role: message.role,
+      content: message.content,
+    }));
+}
+
+type GenerateReplyOptions = {
+  jobId: string;
+  threadId: string;
+  prompt: string;
+  replaceMessageId?: string;
+  version?: number;
+  stream?: {
+    onReady: (payload: {
+      runId: string;
+      threadId: string;
+      messageId: string;
+      requestId: string;
+    }) => void;
+    onDelta: (payload: {
+      runId: string;
+      messageId: string;
+      delta: string;
+    }) => void;
+    onCompleted: (payload: {
+      runId: string;
+      message: Awaited<ReturnType<typeof jobChatRepo.getMessageById>>;
+    }) => void;
+    onCancelled: (payload: {
+      runId: string;
+      message: Awaited<ReturnType<typeof jobChatRepo.getMessageById>>;
+    }) => void;
+    onError: (payload: {
+      runId: string;
+      code: string;
+      message: string;
+      requestId: string;
+    }) => void;
+  };
+};
+
+async function ensureJobThread(jobId: string, title?: string | null) {
+  return jobChatRepo.getOrCreateThreadForJob({
+    jobId,
+    title: title ?? null,
+  });
+}
+
+export async function createThread(input: {
+  jobId: string;
+  title?: string | null;
+}) {
+  return ensureJobThread(input.jobId, input.title);
+}
+
+export async function listThreads(jobId: string) {
+  const thread = await ensureJobThread(jobId);
+  return [thread];
+}
+
+export async function listMessages(input: {
+  jobId: string;
+  threadId: string;
+  limit?: number;
+  offset?: number;
+}) {
+  const thread = await jobChatRepo.getThreadForJob(input.jobId, input.threadId);
+  if (!thread) {
+    throw notFound("Thread not found for this job");
+  }
+
+  return jobChatRepo.listMessagesForThread(input.threadId, {
+    limit: input.limit,
+    offset: input.offset,
+  });
+}
+
+export async function listMessagesForJob(input: {
+  jobId: string;
+  limit?: number;
+  offset?: number;
+}) {
+  const thread = await ensureJobThread(input.jobId);
+  return jobChatRepo.listMessagesForThread(thread.id, {
+    limit: input.limit,
+    offset: input.offset,
+  });
+}
+
+async function runAssistantReply(
+  options: GenerateReplyOptions,
+): Promise<{ runId: string; messageId: string; message: string }> {
+  const thread = await jobChatRepo.getThreadForJob(
+    options.jobId,
+    options.threadId,
+  );
+  if (!thread) {
+    throw notFound("Thread not found for this job");
+  }
+
+  const activeRun = await jobChatRepo.getActiveRunForThread(options.threadId);
+  if (activeRun) {
+    throw conflict("A chat generation is already running for this thread");
+  }
+
+  const [context, llmConfig, history] = await Promise.all([
+    buildJobChatPromptContext(options.jobId),
+    resolveLlmRuntimeSettings(),
+    buildConversationMessages(options.threadId),
+  ]);
+
+  const requestId = getRequestId() ?? "unknown";
+
+  let run: JobChatRun;
+  try {
+    run = await jobChatRepo.createRun({
+      threadId: options.threadId,
+      jobId: options.jobId,
+      model: llmConfig.model,
+      provider: llmConfig.provider,
+      requestId,
+    });
+  } catch (error) {
+    if (isRunningRunUniqueConstraintError(error)) {
+      throw conflict("A chat generation is already running for this thread");
+    }
+    throw error;
+  }
+
+  let assistantMessage: JobChatMessage;
+  try {
+    assistantMessage = await jobChatRepo.createMessage({
+      threadId: options.threadId,
+      jobId: options.jobId,
+      role: "assistant",
+      content: "",
+      status: "partial",
+      version: options.version ?? 1,
+      replacesMessageId: options.replaceMessageId ?? null,
+    });
+  } catch (error) {
+    await jobChatRepo.completeRun(run.id, {
+      status: "failed",
+      errorCode: "INTERNAL_ERROR",
+      errorMessage: "Failed to create assistant message",
+    });
+    throw error;
+  }
+
+  const controller = new AbortController();
+  abortControllers.set(run.id, controller);
+  options.stream?.onReady({
+    runId: run.id,
+    threadId: options.threadId,
+    messageId: assistantMessage.id,
+    requestId,
+  });
+
+  let accumulated = "";
+
+  try {
+    const llm = new LlmService({
+      provider: llmConfig.provider,
+      baseUrl: llmConfig.baseUrl,
+      apiKey: llmConfig.apiKey,
+    });
+
+    const llmResult = await llm.callJson<{ response: string }>({
+      model: llmConfig.model,
+      messages: [
+        {
+          role: "system",
+          content: context.systemPrompt,
+        },
+        {
+          role: "system",
+          content: `Job Context (JSON):\n${context.jobSnapshot}`,
+        },
+        {
+          role: "system",
+          content: `Profile Context:\n${context.profileSnapshot || "No profile context available."}`,
+        },
+        ...history,
+        {
+          role: "user",
+          content: options.prompt,
+        },
+      ],
+      jsonSchema: CHAT_RESPONSE_SCHEMA,
+      maxRetries: 1,
+      retryDelayMs: 300,
+      jobId: options.jobId,
+      signal: controller.signal,
+    });
+
+    if (!llmResult.success) {
+      if (controller.signal.aborted) {
+        throw requestTimeout("Chat generation was cancelled");
+      }
+      throw upstreamError("LLM generation failed", {
+        reason: llmResult.error,
+      });
+    }
+
+    const finalText = (llmResult.data.response || "").trim();
+    const chunks = chunkText(finalText);
+
+    for (const chunk of chunks) {
+      if (controller.signal.aborted) {
+        const cancelled = await jobChatRepo.updateMessage(assistantMessage.id, {
+          content: accumulated,
+          status: "cancelled",
+          tokensIn: estimateTokenCount(options.prompt),
+          tokensOut: estimateTokenCount(accumulated),
+        });
+        await jobChatRepo.completeRun(run.id, {
+          status: "cancelled",
+          errorCode: "REQUEST_TIMEOUT",
+          errorMessage: "Generation cancelled by user",
+        });
+        options.stream?.onCancelled({ runId: run.id, message: cancelled });
+        return {
+          runId: run.id,
+          messageId: assistantMessage.id,
+          message: accumulated,
+        };
+      }
+
+      accumulated += chunk;
+      options.stream?.onDelta({
+        runId: run.id,
+        messageId: assistantMessage.id,
+        delta: chunk,
+      });
+    }
+
+    const completedMessage = await jobChatRepo.updateMessage(
+      assistantMessage.id,
+      {
+        content: accumulated,
+        status: "complete",
+        tokensIn: estimateTokenCount(options.prompt),
+        tokensOut: estimateTokenCount(accumulated),
+      },
+    );
+
+    const runAfterComplete = await jobChatRepo.completeRunIfRunning(run.id, {
+      status: "completed",
+    });
+
+    if (!runAfterComplete || runAfterComplete.status !== "completed") {
+      if (runAfterComplete?.status === "cancelled") {
+        const cancelledMessage = await jobChatRepo.updateMessage(
+          assistantMessage.id,
+          {
+            content: accumulated,
+            status: "cancelled",
+            tokensIn: estimateTokenCount(options.prompt),
+            tokensOut: estimateTokenCount(accumulated),
+          },
+        );
+        options.stream?.onCancelled({
+          runId: run.id,
+          message: cancelledMessage,
+        });
+      }
+      return {
+        runId: run.id,
+        messageId: assistantMessage.id,
+        message: accumulated,
+      };
+    }
+
+    options.stream?.onCompleted({
+      runId: run.id,
+      message: completedMessage,
+    });
+
+    return {
+      runId: run.id,
+      messageId: assistantMessage.id,
+      message: accumulated,
+    };
+  } catch (error) {
+    const appError = error instanceof Error ? error : new Error(String(error));
+    const isCancelled =
+      controller.signal.aborted || appError.name === "AbortError";
+    const status = isCancelled ? "cancelled" : "failed";
+    const code = isCancelled ? "REQUEST_TIMEOUT" : "UPSTREAM_ERROR";
+    const message = isCancelled
+      ? "Generation cancelled by user"
+      : appError.message || "Generation failed";
+
+    const failedMessage = await jobChatRepo.updateMessage(assistantMessage.id, {
+      content: accumulated,
+      status: isCancelled ? "cancelled" : "failed",
+      tokensIn: estimateTokenCount(options.prompt),
+      tokensOut: estimateTokenCount(accumulated),
+    });
+
+    await jobChatRepo.completeRun(run.id, {
+      status,
+      errorCode: code,
+      errorMessage: message,
+    });
+
+    if (isCancelled) {
+      options.stream?.onCancelled({ runId: run.id, message: failedMessage });
+      return {
+        runId: run.id,
+        messageId: assistantMessage.id,
+        message: accumulated,
+      };
+    }
+
+    options.stream?.onError({
+      runId: run.id,
+      code,
+      message,
+      requestId,
+    });
+
+    throw upstreamError(message, { runId: run.id });
+  } finally {
+    abortControllers.delete(run.id);
+    logger.info("Job chat run finished", {
+      jobId: options.jobId,
+      threadId: options.threadId,
+      runId: run.id,
+    });
+  }
+}
+
+export async function sendMessage(input: {
+  jobId: string;
+  threadId: string;
+  content: string;
+  stream?: GenerateReplyOptions["stream"];
+}) {
+  const content = input.content.trim();
+  if (!content) {
+    throw badRequest("Message content is required");
+  }
+
+  const thread = await jobChatRepo.getThreadForJob(input.jobId, input.threadId);
+  if (!thread) {
+    throw notFound("Thread not found for this job");
+  }
+
+  const userMessage = await jobChatRepo.createMessage({
+    threadId: input.threadId,
+    jobId: input.jobId,
+    role: "user",
+    content,
+    status: "complete",
+    tokensIn: estimateTokenCount(content),
+    tokensOut: null,
+  });
+
+  const result = await runAssistantReply({
+    jobId: input.jobId,
+    threadId: input.threadId,
+    prompt: content,
+    stream: input.stream,
+  });
+
+  const assistantMessage = await jobChatRepo.getMessageById(result.messageId);
+  return {
+    userMessage,
+    assistantMessage,
+    runId: result.runId,
+  };
+}
+
+export async function sendMessageForJob(input: {
+  jobId: string;
+  content: string;
+  stream?: GenerateReplyOptions["stream"];
+}) {
+  const thread = await ensureJobThread(input.jobId);
+  return sendMessage({
+    jobId: input.jobId,
+    threadId: thread.id,
+    content: input.content,
+    stream: input.stream,
+  });
+}
+
+export async function regenerateMessage(input: {
+  jobId: string;
+  threadId: string;
+  assistantMessageId: string;
+  stream?: GenerateReplyOptions["stream"];
+}) {
+  const thread = await jobChatRepo.getThreadForJob(input.jobId, input.threadId);
+  if (!thread) {
+    throw notFound("Thread not found for this job");
+  }
+
+  const target = await jobChatRepo.getMessageById(input.assistantMessageId);
+  if (
+    !target ||
+    target.threadId !== input.threadId ||
+    target.jobId !== input.jobId
+  ) {
+    throw notFound("Assistant message not found for this thread");
+  }
+
+  if (target.role !== "assistant") {
+    throw badRequest("Only assistant messages can be regenerated");
+  }
+
+  const latestAssistant = await jobChatRepo.getLatestAssistantMessage(
+    input.threadId,
+  );
+  if (!latestAssistant || latestAssistant.id !== target.id) {
+    throw badRequest("Only the latest assistant message can be regenerated");
+  }
+
+  const messages = await jobChatRepo.listMessagesForThread(input.threadId, {
+    limit: 200,
+  });
+  const targetIndex = messages.findIndex((message) => message.id === target.id);
+  const priorUser =
+    targetIndex > 0
+      ? [...messages.slice(0, targetIndex)]
+          .reverse()
+          .find((message) => message.role === "user")
+      : null;
+
+  if (!priorUser) {
+    throw badRequest("Could not find a user message to regenerate from");
+  }
+
+  const result = await runAssistantReply({
+    jobId: input.jobId,
+    threadId: input.threadId,
+    prompt: priorUser.content,
+    replaceMessageId: target.id,
+    version: (target.version || 1) + 1,
+    stream: input.stream,
+  });
+
+  const assistantMessage = await jobChatRepo.getMessageById(result.messageId);
+
+  return {
+    runId: result.runId,
+    assistantMessage,
+  };
+}
+
+export async function regenerateMessageForJob(input: {
+  jobId: string;
+  assistantMessageId: string;
+  stream?: GenerateReplyOptions["stream"];
+}) {
+  const thread = await ensureJobThread(input.jobId);
+  return regenerateMessage({
+    jobId: input.jobId,
+    threadId: thread.id,
+    assistantMessageId: input.assistantMessageId,
+    stream: input.stream,
+  });
+}
+
+export async function cancelRun(input: {
+  jobId: string;
+  threadId: string;
+  runId: string;
+}): Promise<{ cancelled: boolean; alreadyFinished: boolean }> {
+  const run = await jobChatRepo.getRunById(input.runId);
+  if (!run || run.threadId !== input.threadId || run.jobId !== input.jobId) {
+    throw notFound("Run not found for this thread");
+  }
+
+  if (run.status !== "running") {
+    return {
+      cancelled: false,
+      alreadyFinished: true,
+    };
+  }
+
+  const controller = abortControllers.get(input.runId);
+  if (controller) {
+    controller.abort();
+  }
+
+  const runAfterCancel = await jobChatRepo.completeRunIfRunning(input.runId, {
+    status: "cancelled",
+    errorCode: "REQUEST_TIMEOUT",
+    errorMessage: "Generation cancelled by user",
+  });
+
+  if (!runAfterCancel || runAfterCancel.status !== "cancelled") {
+    return {
+      cancelled: false,
+      alreadyFinished: true,
+    };
+  }
+
+  return {
+    cancelled: true,
+    alreadyFinished: false,
+  };
+}
+
+export async function cancelRunForJob(input: {
+  jobId: string;
+  runId: string;
+}): Promise<{ cancelled: boolean; alreadyFinished: boolean }> {
+  const thread = await ensureJobThread(input.jobId);
+  return cancelRun({
+    jobId: input.jobId,
+    threadId: thread.id,
+    runId: input.runId,
+  });
+}
diff --git a/orchestrator/src/server/services/llm/service.ts b/orchestrator/src/server/services/llm/service.ts
index 8696fc5..1dc987e 100644
--- a/orchestrator/src/server/services/llm/service.ts
+++ b/orchestrator/src/server/services/llm/service.ts
@@ -79,6 +79,7 @@ export class LlmService {
       jsonSchema,
       maxRetries = 0,
       retryDelayMs = 500,
+      signal,
     } = options;
     const jobId = options.jobId;
 
@@ -94,6 +95,7 @@ export class LlmService {
         maxRetries,
         retryDelayMs,
         jobId,
+        signal,
       });
 
       if (result.success) {
@@ -173,9 +175,17 @@ export class LlmService {
     maxRetries: number;
     retryDelayMs: number;
     jobId?: string;
+    signal?: AbortSignal;
   }): Promise<LlmResponse<T>> {
-    const { mode, model, messages, jsonSchema, maxRetries, retryDelayMs } =
-      args;
+    const {
+      mode,
+      model,
+      messages,
+      jsonSchema,
+      maxRetries,
+      retryDelayMs,
+      signal,
+    } = args;
     const jobId = args.jobId;
 
     for (let attempt = 0; attempt <= maxRetries; attempt++) {
@@ -202,6 +212,7 @@ export class LlmService {
           method: "POST",
           headers,
           body: JSON.stringify(body),
+          signal,
         });
 
         if (!response.ok) {
diff --git a/orchestrator/src/server/services/llm/types.ts b/orchestrator/src/server/services/llm/types.ts
index 98f3f9e..f39bc3b 100644
--- a/orchestrator/src/server/services/llm/types.ts
+++ b/orchestrator/src/server/services/llm/types.ts
@@ -30,6 +30,8 @@ export interface LlmRequestOptions<_T> {
   retryDelayMs?: number;
   /** Job ID for logging purposes */
   jobId?: string;
+  /** Optional abort signal for cancellation */
+  signal?: AbortSignal;
 }
 
 export interface LlmResult<T> {
diff --git a/orchestrator/src/server/services/settings-conversion.ts b/orchestrator/src/server/services/settings-conversion.ts
index b0ff436..b8df62a 100644
--- a/orchestrator/src/server/services/settings-conversion.ts
+++ b/orchestrator/src/server/services/settings-conversion.ts
@@ -13,6 +13,10 @@ type SettingsConversionValueMap = {
   jobspyResultsWanted: number;
   jobspyCountryIndeed: string;
   showSponsorInfo: boolean;
+  chatStyleTone: string;
+  chatStyleFormality: string;
+  chatStyleConstraints: string;
+  chatStyleDoNotUse: string;
   backupEnabled: boolean;
   backupHour: number;
   backupMaxCount: number;
@@ -137,6 +141,30 @@ export const settingsConversionMetadata: SettingsConversionMetadata = {
     serialize: serializeBitBool,
     resolve: resolveWithNullishFallback,
   },
+  chatStyleTone: {
+    defaultValue: () => process.env.CHAT_STYLE_TONE || "professional",
+    parseOverride: (raw) => raw ?? null,
+    serialize: (value) => value ?? null,
+    resolve: resolveWithEmptyStringFallback,
+  },
+  chatStyleFormality: {
+    defaultValue: () => process.env.CHAT_STYLE_FORMALITY || "medium",
+    parseOverride: (raw) => raw ?? null,
+    serialize: (value) => value ?? null,
+    resolve: resolveWithEmptyStringFallback,
+  },
+  chatStyleConstraints: {
+    defaultValue: () => process.env.CHAT_STYLE_CONSTRAINTS || "",
+    parseOverride: (raw) => raw ?? null,
+    serialize: (value) => value ?? null,
+    resolve: resolveWithEmptyStringFallback,
+  },
+  chatStyleDoNotUse: {
+    defaultValue: () => process.env.CHAT_STYLE_DO_NOT_USE || "",
+    parseOverride: (raw) => raw ?? null,
+    serialize: (value) => value ?? null,
+    resolve: resolveWithEmptyStringFallback,
+  },
   backupEnabled: {
     defaultValue: () => false,
     parseOverride: parseBitBoolOrNull,
diff --git a/orchestrator/src/server/services/settings-update/registry.ts b/orchestrator/src/server/services/settings-update/registry.ts
index f724e6b..1d0d630 100644
--- a/orchestrator/src/server/services/settings-update/registry.ts
+++ b/orchestrator/src/server/services/settings-update/registry.ts
@@ -188,6 +188,26 @@ export const settingsUpdateRegistry: Partial<{
       actions: [metadataPersistAction("showSponsorInfo", value)],
     }),
   ),
+  chatStyleTone: singleAction(({ value }) =>
+    result({
+      actions: [metadataPersistAction("chatStyleTone", value)],
+    }),
+  ),
+  chatStyleFormality: singleAction(({ value }) =>
+    result({
+      actions: [metadataPersistAction("chatStyleFormality", value)],
+    }),
+  ),
+  chatStyleConstraints: singleAction(({ value }) =>
+    result({
+      actions: [metadataPersistAction("chatStyleConstraints", value)],
+    }),
+  ),
+  chatStyleDoNotUse: singleAction(({ value }) =>
+    result({
+      actions: [metadataPersistAction("chatStyleDoNotUse", value)],
+    }),
+  ),
   llmApiKey: singleAction(({ value }) => {
     const normalized = toNormalizedStringOrNull(value);
     return result({
diff --git a/orchestrator/src/server/services/settings.ts b/orchestrator/src/server/services/settings.ts
index 4038fdf..71425af 100644
--- a/orchestrator/src/server/services/settings.ts
+++ b/orchestrator/src/server/services/settings.ts
@@ -146,6 +146,39 @@ export async function getEffectiveSettings(): Promise<AppSettings> {
   const overrideShowSponsorInfo = showSponsorInfoSetting.overrideValue;
   const showSponsorInfo = showSponsorInfoSetting.value;
 
+  const chatStyleToneSetting = resolveSettingValue(
+    "chatStyleTone",
+    overrides.chatStyleTone,
+  );
+  const defaultChatStyleTone = chatStyleToneSetting.defaultValue;
+  const overrideChatStyleTone = chatStyleToneSetting.overrideValue;
+  const chatStyleTone = chatStyleToneSetting.value;
+
+  const chatStyleFormalitySetting = resolveSettingValue(
+    "chatStyleFormality",
+    overrides.chatStyleFormality,
+  );
+  const defaultChatStyleFormality = chatStyleFormalitySetting.defaultValue;
+  const overrideChatStyleFormality = chatStyleFormalitySetting.overrideValue;
+  const chatStyleFormality = chatStyleFormalitySetting.value;
+
+  const chatStyleConstraintsSetting = resolveSettingValue(
+    "chatStyleConstraints",
+    overrides.chatStyleConstraints,
+  );
+  const defaultChatStyleConstraints = chatStyleConstraintsSetting.defaultValue;
+  const overrideChatStyleConstraints =
+    chatStyleConstraintsSetting.overrideValue;
+  const chatStyleConstraints = chatStyleConstraintsSetting.value;
+
+  const chatStyleDoNotUseSetting = resolveSettingValue(
+    "chatStyleDoNotUse",
+    overrides.chatStyleDoNotUse,
+  );
+  const defaultChatStyleDoNotUse = chatStyleDoNotUseSetting.defaultValue;
+  const overrideChatStyleDoNotUse = chatStyleDoNotUseSetting.overrideValue;
+  const chatStyleDoNotUse = chatStyleDoNotUseSetting.value;
+
   const backupEnabledSetting = resolveSettingValue(
     "backupEnabled",
     overrides.backupEnabled,
@@ -245,6 +278,18 @@ export async function getEffectiveSettings(): Promise<AppSettings> {
     showSponsorInfo,
     defaultShowSponsorInfo,
     overrideShowSponsorInfo,
+    chatStyleTone,
+    defaultChatStyleTone,
+    overrideChatStyleTone,
+    chatStyleFormality,
+    defaultChatStyleFormality,
+    overrideChatStyleFormality,
+    chatStyleConstraints,
+    defaultChatStyleConstraints,
+    overrideChatStyleConstraints,
+    chatStyleDoNotUse,
+    defaultChatStyleDoNotUse,
+    overrideChatStyleDoNotUse,
     backupEnabled,
     defaultBackupEnabled,
     overrideBackupEnabled,
diff --git a/shared/src/settings-schema.ts b/shared/src/settings-schema.ts
index 8aba3ed..07f4280 100644
--- a/shared/src/settings-schema.ts
+++ b/shared/src/settings-schema.ts
@@ -54,6 +54,10 @@ export const updateSettingsSchema = z
       .optional(),
     jobspyCountryIndeed: z.string().trim().max(100).nullable().optional(),
     showSponsorInfo: z.boolean().nullable().optional(),
+    chatStyleTone: z.string().trim().max(100).nullable().optional(),
+    chatStyleFormality: z.string().trim().max(100).nullable().optional(),
+    chatStyleConstraints: z.string().trim().max(4000).nullable().optional(),
+    chatStyleDoNotUse: z.string().trim().max(1000).nullable().optional(),
     rxresumeEmail: z.string().trim().max(200).nullable().optional(),
     rxresumePassword: z.string().trim().max(2000).nullable().optional(),
     basicAuthUser: z.string().trim().max(200).nullable().optional(),
diff --git a/shared/src/testing/factories.ts b/shared/src/testing/factories.ts
index 3373398..2b2a087 100644
--- a/shared/src/testing/factories.ts
+++ b/shared/src/testing/factories.ts
@@ -179,6 +179,18 @@ export const createAppSettings = (
   showSponsorInfo: true,
   defaultShowSponsorInfo: true,
   overrideShowSponsorInfo: null,
+  chatStyleTone: "professional",
+  defaultChatStyleTone: "professional",
+  overrideChatStyleTone: null,
+  chatStyleFormality: "medium",
+  defaultChatStyleFormality: "medium",
+  overrideChatStyleFormality: null,
+  chatStyleConstraints: "",
+  defaultChatStyleConstraints: "",
+  overrideChatStyleConstraints: null,
+  chatStyleDoNotUse: "",
+  defaultChatStyleDoNotUse: "",
+  overrideChatStyleDoNotUse: null,
   llmApiKeyHint: null,
   rxresumeEmail: null,
   rxresumePasswordHint: null,
diff --git a/shared/src/types.ts b/shared/src/types.ts
index 1605cad..f220f74 100644
--- a/shared/src/types.ts
+++ b/shared/src/types.ts
@@ -620,6 +620,102 @@ export interface BulkJobActionResponse {
   results: BulkJobActionResult[];
 }
 
+export const JOB_CHAT_MESSAGE_ROLES = [
+  "system",
+  "user",
+  "assistant",
+  "tool",
+] as const;
+export type JobChatMessageRole = (typeof JOB_CHAT_MESSAGE_ROLES)[number];
+
+export const JOB_CHAT_MESSAGE_STATUSES = [
+  "complete",
+  "partial",
+  "cancelled",
+  "failed",
+] as const;
+export type JobChatMessageStatus = (typeof JOB_CHAT_MESSAGE_STATUSES)[number];
+
+export const JOB_CHAT_RUN_STATUSES = [
+  "running",
+  "completed",
+  "cancelled",
+  "failed",
+] as const;
+export type JobChatRunStatus = (typeof JOB_CHAT_RUN_STATUSES)[number];
+
+export interface JobChatThread {
+  id: string;
+  jobId: string;
+  title: string | null;
+  createdAt: string;
+  updatedAt: string;
+  lastMessageAt: string | null;
+}
+
+export interface JobChatMessage {
+  id: string;
+  threadId: string;
+  jobId: string;
+  role: JobChatMessageRole;
+  content: string;
+  status: JobChatMessageStatus;
+  tokensIn: number | null;
+  tokensOut: number | null;
+  version: number;
+  replacesMessageId: string | null;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface JobChatRun {
+  id: string;
+  threadId: string;
+  jobId: string;
+  status: JobChatRunStatus;
+  model: string | null;
+  provider: string | null;
+  errorCode: string | null;
+  errorMessage: string | null;
+  startedAt: number;
+  completedAt: number | null;
+  requestId: string | null;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export type JobChatStreamEvent =
+  | {
+      type: "ready";
+      runId: string;
+      threadId: string;
+      messageId: string;
+      requestId: string;
+    }
+  | {
+      type: "delta";
+      runId: string;
+      messageId: string;
+      delta: string;
+    }
+  | {
+      type: "completed";
+      runId: string;
+      message: JobChatMessage;
+    }
+  | {
+      type: "cancelled";
+      runId: string;
+      message: JobChatMessage;
+    }
+  | {
+      type: "error";
+      runId: string;
+      code: string;
+      message: string;
+      requestId: string;
+    };
+
 // Visa Sponsors types
 export interface VisaSponsor {
   organisationName: string;
@@ -817,6 +913,18 @@ export interface AppSettings {
   showSponsorInfo: boolean;
   defaultShowSponsorInfo: boolean;
   overrideShowSponsorInfo: boolean | null;
+  chatStyleTone: string;
+  defaultChatStyleTone: string;
+  overrideChatStyleTone: string | null;
+  chatStyleFormality: string;
+  defaultChatStyleFormality: string;
+  overrideChatStyleFormality: string | null;
+  chatStyleConstraints: string;
+  defaultChatStyleConstraints: string;
+  overrideChatStyleConstraints: string | null;
+  chatStyleDoNotUse: string;
+  defaultChatStyleDoNotUse: string;
+  overrideChatStyleDoNotUse: string | null;
   llmApiKeyHint: string | null;
   rxresumeEmail: string | null;
   rxresumePasswordHint: string | null;