diff --git a/src/app/api/insights/chat/route.ts b/src/app/api/insights/chat/route.ts
index aedc94be7..f418a1c7e 100644
--- a/src/app/api/insights/chat/route.ts
+++ b/src/app/api/insights/chat/route.ts
@@ -567,6 +567,10 @@ Reply now as the assistant, in ${locale === "de" ? "German" : "English"}. Fetch
           user: userPrompt,
           temperature: AI_BUDGETS.coach.temperature,
           maxTokens: AI_BUDGETS.coach.maxTokens,
+          // v1.20.1 — thread the request's abort signal so a mid-generation
+          // client disconnect tears the upstream provider call down instead of
+          // paying the full token cost into a closed connection.
+          signal: request.signal,
         }),
       });
       result = fallback.result;
diff --git a/src/lib/ai/anthropic-client.ts b/src/lib/ai/anthropic-client.ts
index 97162de03..00c704701 100644
--- a/src/lib/ai/anthropic-client.ts
+++ b/src/lib/ai/anthropic-client.ts
@@ -259,7 +259,9 @@ export class AnthropicClient implements AIProvider {
       // 60 s ceiling — see openai-client.ts for the rationale.
       // v1.11.2 — base URL is user/admin-overridable; pin the connect-time DNS
       // check so a private/metadata address is rejected (SSRF/rebinding).
-      { timeoutMs: 60_000, requirePublicHost: true },
+      // v1.20.1 — compose the caller's cancel signal (Coach SSE disconnect) so
+      // a mid-generation abort tears the upstream call down early.
+      { timeoutMs: 60_000, requirePublicHost: true, signal: params.signal },
     );
 
     if (!res.ok) {
diff --git a/src/lib/ai/codex-client.ts b/src/lib/ai/codex-client.ts
index 2be9fcf8c..dcae2020a 100644
--- a/src/lib/ai/codex-client.ts
+++ b/src/lib/ai/codex-client.ts
@@ -467,7 +467,9 @@ export class CodexClient implements AIProvider {
         // clients use so a long generation is not clipped by the 15 s
         // default while still bounding a tar-pit upstream.
       },
-      { timeoutMs: 60_000 },
+      // v1.20.1 — compose the caller's cancel signal (Coach SSE disconnect) so
+      // a mid-generation abort tears the upstream call down early.
+      { timeoutMs: 60_000, signal: params.signal },
     );
   }
 
diff --git a/src/lib/ai/local-client.ts b/src/lib/ai/local-client.ts
index 477d9bebc..fa41db7d7 100644
--- a/src/lib/ai/local-client.ts
+++ b/src/lib/ai/local-client.ts
@@ -125,7 +125,13 @@ export class LocalOpenAICompatibleClient implements AIProvider {
           ...(params.responseFormat === "json" ? { format: "json" } : {}),
         }),
       },
-      { timeoutMs: 60_000, requirePublicHost: !allowPrivate },
+      // v1.20.1 — compose the caller's cancel signal (Coach SSE disconnect) so
+      // a mid-generation abort tears the upstream call down early.
+      {
+        timeoutMs: 60_000,
+        requirePublicHost: !allowPrivate,
+        signal: params.signal,
+      },
     );
 
     if (!res.ok) {
diff --git a/src/lib/ai/openai-client.ts b/src/lib/ai/openai-client.ts
index e4a8c808d..f84cda5f4 100644
--- a/src/lib/ai/openai-client.ts
+++ b/src/lib/ai/openai-client.ts
@@ -90,7 +90,9 @@ export class OpenAIClient implements AIProvider {
       // v1.11.2 — the base URL is user/admin-overridable (BYO gateway), so pin
       // the connect-time DNS check: a base URL resolving to a private/metadata
       // address is rejected, closing the SSRF/rebinding surface.
-      { timeoutMs: 60_000, requirePublicHost: true },
+      // v1.20.1 — compose the caller's cancel signal (Coach SSE disconnect) so
+      // a mid-generation abort tears the upstream call down early.
+      { timeoutMs: 60_000, requirePublicHost: true, signal: params.signal },
     );
 
     if (!res.ok) {
diff --git a/src/lib/ai/types.ts b/src/lib/ai/types.ts
index 0e1cc8028..318becc18 100644
--- a/src/lib/ai/types.ts
+++ b/src/lib/ai/types.ts
@@ -271,6 +271,15 @@ export interface CompletionParams {
    * Mapped per provider; omitted from the wire when unset.
    */
   toolChoice?: "auto" | "none";
+  /**
+   * v1.20.1 — optional caller-owned cancellation signal. Threaded onto the
+   * client's `safeFetch` so a mid-generation client disconnect (the Coach SSE
+   * route wires `request.signal` here) tears the upstream provider request
+   * down instead of running it to completion and paying the full token cost
+   * into a closed connection. Composed with the per-client timeout inside
+   * `safeFetch`. Omitted → behaviour is unchanged (timeout-only).
+   */
+  signal?: AbortSignal;
 }
 
 export interface CompletionResult {
@@ -313,6 +322,8 @@ export function singleUserTurn(p: {
   documents?: CompletionDocument[];
   tools?: AiToolDef[];
   toolChoice?: "auto" | "none";
+  /** v1.20.1 — caller-owned cancel signal threaded to the client fetch. */
+  signal?: AbortSignal;
 }): CompletionParams {
   const images = p.images ?? [];
   const documents = p.documents ?? [];
@@ -349,6 +360,7 @@ export function singleUserTurn(p: {
     responseFormat: p.responseFormat,
     tools: p.tools,
     toolChoice: p.toolChoice,
+    signal: p.signal,
   };
 }