diff --git a/src/shared/model-suggestion-retry.test.ts b/src/shared/model-suggestion-retry.test.ts
index 52edba3aa..9732367de 100644
--- a/src/shared/model-suggestion-retry.test.ts
+++ b/src/shared/model-suggestion-retry.test.ts
@@ -399,6 +399,43 @@ describe("promptSyncWithModelSuggestionRetry", () => {
     expect(promptAsyncMock).toHaveBeenCalledTimes(0)
   })
 
+  it("should abort and throw timeout error when sync prompt hangs", async () => {
+    // given a client where sync prompt never resolves unless aborted
+    let receivedSignal: AbortSignal | undefined
+    const promptMock = mock((input: { signal?: AbortSignal }) => {
+      receivedSignal = input.signal
+      return new Promise((_, reject) => {
+        const signal = input.signal
+        if (!signal) {
+          return
+        }
+        signal.addEventListener("abort", () => {
+          reject(signal.reason)
+        })
+      })
+    })
+    const client = {
+      session: {
+        prompt: promptMock,
+        promptAsync: mock(() => Promise.resolve()),
+      },
+    }
+
+    // when calling with short timeout
+    // then should abort the request and throw timeout error
+    await expect(
+      promptSyncWithModelSuggestionRetry(client as any, {
+        path: { id: "session-1" },
+        body: {
+          parts: [{ type: "text", text: "hello" }],
+          model: { providerID: "anthropic", modelID: "claude-sonnet-4" },
+        },
+      }, { timeoutMs: 1 })
+    ).rejects.toThrow("prompt timed out after 1ms")
+
+    expect(receivedSignal?.aborted).toBe(true)
+  })
+
   it("should retry with suggested model on ProviderModelNotFoundError", async () => {
     // given a client that fails first with model-not-found, then succeeds
     const promptMock = mock()
diff --git a/src/shared/model-suggestion-retry.ts b/src/shared/model-suggestion-retry.ts
index 6a34deacb..0ff9ca86e 100644
--- a/src/shared/model-suggestion-retry.ts
+++ b/src/shared/model-suggestion-retry.ts
@@ -1,5 +1,10 @@
 import type { createOpencodeClient } from "@opencode-ai/sdk"
 import { log } from "./logger"
+import {
+  createPromptTimeoutContext,
+  PROMPT_TIMEOUT_MS,
+  type PromptRetryOptions,
+} from "./prompt-timeout-context"
 
 type Client = ReturnType<typeof createOpencodeClient>
 
@@ -77,30 +82,36 @@ interface PromptBody {
 interface PromptArgs {
   path: { id: string }
   body: PromptBody
+  signal?: AbortSignal
   [key: string]: unknown
 }
 
 export async function promptWithModelSuggestionRetry(
   client: Client,
   args: PromptArgs,
+  options: PromptRetryOptions = {},
 ): Promise<void> {
+  const timeoutMs = options.timeoutMs ?? PROMPT_TIMEOUT_MS
+  const timeoutContext = createPromptTimeoutContext(args, timeoutMs)
   // NOTE: Model suggestion retry removed — promptAsync returns 204 immediately,
   // model errors happen asynchronously server-side and cannot be caught here
-  const promptPromise = client.session.promptAsync(
-    args as Parameters<typeof client.session.promptAsync>[0],
-  )
-
-  let timeoutID: ReturnType<typeof setTimeout> | null = null
-  const timeoutPromise = new Promise<never>((_, reject) => {
-    timeoutID = setTimeout(() => {
-      reject(new Error("promptAsync timed out after 120000ms"))
-    }, 120000)
-  })
+  const promptPromise = client.session.promptAsync({
+    ...args,
+    signal: timeoutContext.signal,
+  } as Parameters<typeof client.session.promptAsync>[0])
 
   try {
-    await Promise.race([promptPromise, timeoutPromise])
+    await promptPromise
+    if (timeoutContext.wasTimedOut()) {
+      throw new Error(`promptAsync timed out after ${timeoutMs}ms`)
+    }
+  } catch (error) {
+    if (timeoutContext.wasTimedOut()) {
+      throw new Error(`promptAsync timed out after ${timeoutMs}ms`)
+    }
+    throw error
   } finally {
-    if (timeoutID !== null) clearTimeout(timeoutID)
+    timeoutContext.cleanup()
   }
 }
 
@@ -116,9 +127,28 @@ export async function promptWithModelSuggestionRetry(
 export async function promptSyncWithModelSuggestionRetry(
   client: Client,
   args: PromptArgs,
+  options: PromptRetryOptions = {},
 ): Promise<void> {
+  const timeoutMs = options.timeoutMs ?? PROMPT_TIMEOUT_MS
+
   try {
-    await client.session.prompt(args as Parameters<typeof client.session.prompt>[0])
+    const timeoutContext = createPromptTimeoutContext(args, timeoutMs)
+    try {
+      await client.session.prompt({
+        ...args,
+        signal: timeoutContext.signal,
+      } as Parameters<typeof client.session.prompt>[0])
+      if (timeoutContext.wasTimedOut()) {
+        throw new Error(`prompt timed out after ${timeoutMs}ms`)
+      }
+    } catch (error) {
+      if (timeoutContext.wasTimedOut()) {
+        throw new Error(`prompt timed out after ${timeoutMs}ms`)
+      }
+      throw error
+    } finally {
+      timeoutContext.cleanup()
+    }
   } catch (error) {
     const suggestion = parseModelSuggestion(error)
     if (!suggestion || !args.body.model) {
@@ -130,7 +160,7 @@ export async function promptSyncWithModelSuggestionRetry(
       suggested: suggestion.suggestion,
     })
 
-    await client.session.prompt({
+    const retryArgs: PromptArgs = {
       ...args,
       body: {
         ...args.body,
@@ -139,6 +169,24 @@ export async function promptSyncWithModelSuggestionRetry(
           modelID: suggestion.suggestion,
         },
       },
-    } as Parameters<typeof client.session.prompt>[0])
+    }
+
+    const timeoutContext = createPromptTimeoutContext(retryArgs, timeoutMs)
+    try {
+      await client.session.prompt({
+        ...retryArgs,
+        signal: timeoutContext.signal,
+      } as Parameters<typeof client.session.prompt>[0])
+      if (timeoutContext.wasTimedOut()) {
+        throw new Error(`prompt timed out after ${timeoutMs}ms`)
+      }
+    } catch (retryError) {
+      if (timeoutContext.wasTimedOut()) {
+        throw new Error(`prompt timed out after ${timeoutMs}ms`)
+      }
+      throw retryError
+    } finally {
+      timeoutContext.cleanup()
+    }
   }
 }
diff --git a/src/shared/prompt-timeout-context.ts b/src/shared/prompt-timeout-context.ts
new file mode 100644
index 000000000..99f081278
--- /dev/null
+++ b/src/shared/prompt-timeout-context.ts
@@ -0,0 +1,49 @@
+export interface PromptTimeoutArgs {
+  signal?: AbortSignal
+}
+
+export interface PromptRetryOptions {
+  timeoutMs?: number
+}
+
+export const PROMPT_TIMEOUT_MS = 120000
+
+export function createPromptTimeoutContext(args: PromptTimeoutArgs, timeoutMs: number): {
+  signal: AbortSignal
+  wasTimedOut: () => boolean
+  cleanup: () => void
+} {
+  const timeoutController = new AbortController()
+  let timeoutID: ReturnType<typeof setTimeout> | null = null
+  let timedOut = false
+
+  const abortOnUpstreamSignal = (): void => {
+    timeoutController.abort(args.signal?.reason)
+  }
+
+  if (args.signal) {
+    if (args.signal.aborted) {
+      timeoutController.abort(args.signal.reason)
+    } else {
+      args.signal.addEventListener("abort", abortOnUpstreamSignal, { once: true })
+    }
+  }
+
+  timeoutID = setTimeout(() => {
+    timedOut = true
+    timeoutController.abort(new Error(`prompt timed out after ${timeoutMs}ms`))
+  }, timeoutMs)
+
+  return {
+    signal: timeoutController.signal,
+    wasTimedOut: () => timedOut,
+    cleanup: () => {
+      if (timeoutID !== null) {
+        clearTimeout(timeoutID)
+      }
+      if (args.signal) {
+        args.signal.removeEventListener("abort", abortOnUpstreamSignal)
+      }
+    },
+  }
+}