Add configurable retries for transient provider errors#54
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Cursor Bugbot has reviewed your changes using high effort and found 2 potential issues.
Autofix Details
Bugbot Autofix prepared fixes for both issues found in the latest run.
- ✅ Fixed: Retry wrapper swallows stream errors
- Wrapped the retry loop in a catch that now converts thrown stream/replay errors into terminal assistant error events so the output stream always ends.
- ✅ Fixed: Missing TSDoc on exports
- Added TSDoc comments for retry policy constants and both exported helpers to document behavior, caps, and scope of model wrapping.
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@cursor push ced4bfe0cd
Preview (ced4bfe0cd)
diff --git a/packages/agent/src/provider-retry.ts b/packages/agent/src/provider-retry.ts
--- a/packages/agent/src/provider-retry.ts
+++ b/packages/agent/src/provider-retry.ts
@@ -12,8 +12,11 @@
type SimpleStreamOptions,
} from "@earendil-works/pi-ai";
+/** Maximum number of attempts, including the initial request. */
const MAX_ATTEMPTS = 4;
+/** Default cap for provider-suggested retry delays when callers do not set one. */
const DEFAULT_MAX_RETRY_DELAY_MS = 60_000;
+/** Largest timeout accepted by JS timers; longer waits are split into chunks. */
const MAX_TIMER_DELAY_MS = 2_147_483_647;
type RetryStreamFn = (
@@ -22,48 +25,65 @@
options?: SimpleStreamOptions,
) => AssistantMessageEventStream;
+/**
+ * Wraps a streaming call with retry handling for retryable provider errors.
+ *
+ * The wrapper retries up to `MAX_ATTEMPTS` with exponential backoff and optional
+ * provider-specified delays, then replays the terminal attempt to the caller.
+ */
export function withProviderRetry(streamFn: StreamFn): RetryStreamFn {
return (model, context, options) => {
const output = createAssistantMessageEventStream();
void (async () => {
- for (let attempt = 0; attempt < MAX_ATTEMPTS; attempt += 1) {
- if (options?.signal?.aborted) {
- replayAborted(output, model);
- return;
- }
+ try {
+ for (let attempt = 0; attempt < MAX_ATTEMPTS; attempt += 1) {
+ if (options?.signal?.aborted) {
+ replayAborted(output, model);
+ return;
+ }
- const input = await streamFn(model, context, options);
- const events: AssistantMessageEvent[] = [];
- for await (const event of input) events.push(structuredClone(event));
- const terminal = events.at(-1);
- const message = terminalMessage(terminal);
- if (
- !message ||
- message.stopReason !== "error" ||
- !isRetryableAssistantError(message) ||
- attempt === MAX_ATTEMPTS - 1
- ) {
- replay(output, events, message);
- return;
- }
+ const input = await streamFn(model, context, options);
+ const events: AssistantMessageEvent[] = [];
+ for await (const event of input) events.push(structuredClone(event));
+ const terminal = events.at(-1);
+ const message = terminalMessage(terminal);
+ if (
+ !message ||
+ message.stopReason !== "error" ||
+ !isRetryableAssistantError(message) ||
+ attempt === MAX_ATTEMPTS - 1
+ ) {
+ replay(output, events, message);
+ return;
+ }
- const providerDelay = parseProviderDelay(message.errorMessage);
- const cap = options?.maxRetryDelayMs ?? DEFAULT_MAX_RETRY_DELAY_MS;
- if (providerDelay !== undefined && cap > 0 && providerDelay > cap) {
- replay(output, events, message);
- return;
+ const providerDelay = parseProviderDelay(message.errorMessage);
+ const cap = options?.maxRetryDelayMs ?? DEFAULT_MAX_RETRY_DELAY_MS;
+ if (providerDelay !== undefined && cap > 0 && providerDelay > cap) {
+ replay(output, events, message);
+ return;
+ }
+ const delay = Math.max(2_000 * 2 ** attempt, providerDelay ?? 0);
+ if (!(await wait(delay, options?.signal))) {
+ replayAborted(output, model);
+ return;
+ }
}
- const delay = Math.max(2_000 * 2 ** attempt, providerDelay ?? 0);
- if (!(await wait(delay, options?.signal))) {
- replayAborted(output, model);
- return;
- }
+ } catch (error) {
+ if (options?.signal?.aborted) replayAborted(output, model);
+ else replayUnexpectedError(output, model, error);
}
})();
return output;
};
}
+/**
+ * Returns a `Models` wrapper that applies provider retries to simple call paths.
+ *
+ * Only `streamSimple` and `completeSimple` are wrapped because Agent/Harness use
+ * those APIs; generic `stream` and `complete` pass through unchanged.
+ */
export function withProviderRetryModels(models: Models): Models {
const streamSimple = withProviderRetry((model, context, options) => models.streamSimple(model, context, options));
return {
@@ -98,7 +118,34 @@
}
function replayAborted(output: ReturnType<typeof createAssistantMessageEventStream>, model: Model<Api>): void {
- const message: AssistantMessage = {
+ const message = terminalErrorMessage(model, "aborted", "Request aborted");
+ output.push({ type: "start", partial: structuredClone(message) });
+ output.push({ type: "error", reason: "aborted", error: message });
+ output.end(message);
+}
+
+function replayUnexpectedError(
+ output: ReturnType<typeof createAssistantMessageEventStream>,
+ model: Model<Api>,
+ error: unknown,
+): void {
+ const errorMessage = error instanceof Error ? error.message : String(error);
+ const message = terminalErrorMessage(
+ model,
+ "error",
+ errorMessage || "Unexpected error while handling provider retry stream",
+ );
+ output.push({ type: "start", partial: message });
+ output.push({ type: "error", reason: "error", error: message });
+ output.end(message);
+}
+
+function terminalErrorMessage(
+ model: Model<Api>,
+ stopReason: Extract<AssistantMessage["stopReason"], "aborted" | "error">,
+ errorMessage: string,
+): AssistantMessage {
+ return {
role: "assistant",
content: [],
api: model.api,
@@ -112,13 +159,10 @@
totalTokens: 0,
cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
},
- stopReason: "aborted",
- errorMessage: "Request aborted",
+ stopReason,
+ errorMessage,
timestamp: Date.now(),
};
- output.push({ type: "start", partial: structuredClone(message) });
- output.push({ type: "error", reason: "aborted", error: message });
- output.end(message);
}
function parseProviderDelay(message: string | undefined): number | undefined {
diff --git a/packages/agent/test/provider-retry.test.ts b/packages/agent/test/provider-retry.test.ts
--- a/packages/agent/test/provider-retry.test.ts
+++ b/packages/agent/test/provider-retry.test.ts
@@ -164,6 +164,30 @@
expect(deltas[1].partial.content).toEqual([{ type: "text", text: "ab" }]);
});
+ it("converts stream function rejections into terminal errors", async () => {
+ const retrying = withProviderRetry(async () => {
+ throw new Error("network exploded");
+ });
+ const result = await retrying(model, context).result();
+
+ expect(result.stopReason).toBe("error");
+ expect(result.errorMessage).toContain("network exploded");
+ });
+
+ it("converts stream processing failures into terminal errors", async () => {
+ const retrying = withProviderRetry(() => {
+ const stream = createAssistantMessageEventStream();
+ const value = assistant("stop");
+ stream.push({ type: "start", partial: value });
+ stream.push({ type: "start", partial: value, cannotClone: () => null } as unknown as AssistantMessageEvent);
+ return stream;
+ });
+ const result = await retrying(model, context).result();
+
+ expect(result.stopReason).toBe("error");
+ expect(result.errorMessage).toBeTruthy();
+ });
+
it("applies retries to Models.completeSimple", async () => {
vi.useFakeTimers();
let calls = 0;You can send follow-ups to the cloud agent here.
rgarcia
changed the title
There was a problem hiding this comment.
Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.
Bugbot Autofix prepared a fix for the issue found in the latest run.
- ✅ Fixed: Finally overwrites replay failure end
- I added an
endedguard insettleso replay-failure paths calloutput.end(failure)only once and are not overwritten by thefinallyend call, and added a regression test for that case.
- I added an
Or push these changes by commenting:
@cursor push 48dd714a5e
Preview (48dd714a5e)
diff --git a/packages/agent/src/provider-retry.ts b/packages/agent/src/provider-retry.ts
--- a/packages/agent/src/provider-retry.ts
+++ b/packages/agent/src/provider-retry.ts
@@ -109,6 +109,7 @@
if (settled) return;
settled = true;
let terminalEmitted = false;
+ let ended = false;
try {
if (events) {
for (const event of events) {
@@ -128,11 +129,11 @@
} catch {
// end(result) still settles result() and any waiting iterator.
}
+ ended = true;
output.end(failure);
- return;
}
} finally {
- output.end(message);
+ if (!ended) output.end(message);
}
};
diff --git a/packages/agent/test/provider-retry.test.ts b/packages/agent/test/provider-retry.test.ts
--- a/packages/agent/test/provider-retry.test.ts
+++ b/packages/agent/test/provider-retry.test.ts
@@ -205,6 +205,20 @@
expect(calls).toBe(3);
});
+ it("keeps replay failure terminal message", async () => {
+ const retrying = withProviderRetry((() => textStream("ok")) as StreamFn, enabled);
+ const stream = retrying(model, context);
+ const push = stream.push.bind(stream);
+ let calls = 0;
+ (stream as typeof stream & { push: typeof stream.push }).push = (event) => {
+ if (calls++ === 0) throw new Error("replay failed");
+ return push(event);
+ };
+ const result = await stream.result();
+ expect(result.stopReason).toBe("error");
+ expect(result.errorMessage).toContain("Failed to replay provider response: replay failed");
+ });
+
it("aborts before the first request and during backoff", async () => {
const alreadyAborted = new AbortController();
alreadyAborted.abort();You can send follow-ups to the cloud agent here.
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Summary
retry.enabled,retry.maxRetries, andretry.baseDelayMsthroughCuaAgent,CuaAgentHarness, and the CLI harness builderTesting
npm run typechecknpm run build --workspace @onkernel/cua-clinpm exec --workspace @onkernel/cua-agent vitest -- run test/provider-retry.test.ts test/agent.test.ts(49 passed)npm exec --workspace @onkernel/cua-cli vitest -- run test/action-runner.test.ts(6 passed)npm test --workspace @onkernel/cua-agent(104 passed, 12 skipped)npm test --workspace @onkernel/cua-cli(81 passed, 5 skipped)Note
Medium Risk
Changes how provider streams are consumed and can multiply API calls when retries are enabled; default-off preserves prior behavior.
Overview
Adds opt-in retries around each provider request for transient failures (rate limits, 503s, network/timeouts), using pi-ai’s retryable-error and context-overflow checks. Disabled by default; when enabled, defaults are 3 extra attempts with 2s / 4s / 8s exponential backoff (
retry.enabled,retry.maxRetries,retry.baseDelayMs).CuaAgentwraps the stream function;CuaAgentHarnessand the CLIbuildCuaHarnesswrapModels.streamSimple/completeSimpleonly (genericstream/completeunchanged). Failed attempts are buffered and discarded so partial deltas are not replayed; a successful attempt replays one clean event sequence. Abort signals skip work before the first call and during backoff.Exports
CuaRetryOptionsfrom the agent package. Covered byprovider-retry, agent, and CLI action-runner tests.Reviewed by Cursor Bugbot for commit 2679597. Bugbot is set up for automated code reviews on this repo. Configure here.