fix(prompt-retry): preserve peer prompt reservations

src/features/background-agent/spawner.ts

@@ -1,6 +1,5 @@
 import { createInternalAgentTextPart, getAgentToolRestrictions, log, promptWithRetryInDirectory } from "../../shared"
 import { stripAgentListSortPrefix } from "../../shared/agent-display-names"
-import { releasePromptAsyncReservation } from "../../shared/prompt-async-gate"
 import { applySessionPromptParams } from "../../shared/session-prompt-params-helpers"
 import { setSessionTools } from "../../shared/session-tools-store"
 import { isInsideTmux } from "../../shared/tmux"
@@ -192,7 +191,6 @@ export async function startTask(
         taskId: task.id,
       })
       try {
-        releasePromptAsyncReservation(sessionID, "model-suggestion-retry")
         const fallbackBody = buildFallbackBody(promptBody, FALLBACK_AGENT, {
           includeTeamToolDenylist: input.teamRunId === undefined,
         })
@@ -336,7 +334,6 @@ export async function resumeTask(
         taskId: task.id,
       })
       try {
-        releasePromptAsyncReservation(sessionID, "model-suggestion-retry")
         const fallbackBody = buildFallbackBody(resumeBody, FALLBACK_AGENT, {
           includeTeamToolDenylist: task.teamRunId === undefined,
         })

src/shared/model-suggestion-retry.test.ts

@@ -1,4 +1,5 @@
-import { describe, it, expect, mock } from "bun:test"
+import { afterEach, describe, it, expect, mock } from "bun:test"
+import { dispatchInternalPrompt, releaseAllPromptAsyncReservationsForTesting } from "./prompt-async-gate"
 import { parseModelSuggestion, promptWithModelSuggestionRetry, promptSyncWithModelSuggestionRetry } from "./model-suggestion-retry"
 import { unsafeTestValue } from "../../test-support/unsafe-test-value"
 
@@ -212,6 +213,11 @@ describe("parseModelSuggestion", () => {
 })
 
 describe("promptWithModelSuggestionRetry", () => {
+  afterEach(() => {
+    // then
+    releaseAllPromptAsyncReservationsForTesting()
+  })
+
   it("should succeed on first try without retry", async () => {
     // given a client where promptAsync succeeds
     const promptMock = mock(() => Promise.resolve())
@@ -291,6 +297,42 @@ describe("promptWithModelSuggestionRetry", () => {
     expect(promptMock).toHaveBeenCalledTimes(1)
   })
 
+  it("#given same-source retry observes a peer reservation #when it rejects #then the peer hold remains reserved", async () => {
+    // given
+    const promptMock = mock(async () => undefined)
+    const client = {
+      session: {
+        promptAsync: promptMock,
+      },
+    }
+    const args = {
+      path: { id: "session-peer-reservation" },
+      body: {
+        parts: [{ type: "text", text: "hello" }],
+        model: { providerID: "anthropic", modelID: "claude-sonnet-4" },
+      },
+    }
+
+    // when
+    await promptWithModelSuggestionRetry(unsafeTestValue(client), args)
+    await expect(
+      promptWithModelSuggestionRetry(unsafeTestValue(client), args)
+    ).rejects.toThrow("promptAsync skipped by gate: reserved")
+    const third = await dispatchInternalPrompt({
+      mode: "async",
+      client,
+      sessionID: "session-peer-reservation",
+      input: args,
+      source: "test:third",
+      settleMs: 0,
+      postDispatchHoldMs: 0,
+    })
+
+    // then
+    expect(third).toEqual({ status: "reserved", reservedBy: "model-suggestion-retry" })
+    expect(promptMock).toHaveBeenCalledTimes(1)
+  })
+
   it("should throw error from promptAsync directly on model-not-found error", async () => {
     // given a client that fails with model-not-found error
     const promptMock = mock().mockRejectedValueOnce({

src/shared/model-suggestion-retry.ts

@@ -8,6 +8,7 @@ import {
 import {
   dispatchInternalPrompt,
   releasePromptAsyncReservation,
+  type InternalPromptDispatchResult,
 } from "./prompt-async-gate"
 
 type Client = ReturnType<typeof createOpencodeClient>
@@ -97,9 +98,10 @@ export async function promptWithModelSuggestionRetry(
 ): Promise<void> {
   const timeoutMs = options.timeoutMs ?? PROMPT_TIMEOUT_MS
   const timeoutContext = createPromptTimeoutContext(args, timeoutMs)
+  let promptResult: InternalPromptDispatchResult | undefined
 
   try {
-    const promptResult = await dispatchInternalPrompt({
+    promptResult = await dispatchInternalPrompt({
       mode: "async",
       client,
       sessionID: args.path.id,
@@ -123,7 +125,9 @@ export async function promptWithModelSuggestionRetry(
     if (timeoutContext.wasTimedOut()) {
       throw new Error(`promptAsync timed out after ${timeoutMs}ms`)
     }
-    releasePromptAsyncReservation(args.path.id, "model-suggestion-retry")
+    if (promptResult?.status === "failed") {
+      releasePromptAsyncReservation(args.path.id, "model-suggestion-retry")
+    }
     throw error
   } finally {
     timeoutContext.cleanup()