fix(cursor): retain SDK failure codes and retryability

packages/provider-cursor/src/server/CursorAgentSdk.ts

@@ -58,6 +58,17 @@ export function isCursorUsageLimitError(cause: unknown): boolean {
   );
 }
 
+export function cursorSdkFailureMetadata(cause: unknown) {
+  const error = isCursorAgentSdkRunnerError(cause) ? cause.cause : cause;
+  if (typeof error !== "object" || error === null) return {};
+  const code = Reflect.get(error, "code");
+  const retryable = Reflect.get(error, "isRetryable");
+  return {
+    ...(typeof code === "string" ? { code } : {}),
+    ...(typeof retryable === "boolean" ? { retryable } : {}),
+  };
+}
+
 const GENERIC_SDK_ERROR_CODES = new Set(["", "error", "unknown"]);
 
 function sdkErrorReason(cause: unknown): string | undefined {

packages/provider-cursor/src/server/adapter.test.ts

@@ -53,7 +53,7 @@ const cursorBackendUrl = await vi.hoisted(async () => {
   return url;
 });
 
-const { Agent, ConfigurationError } = loadCursorSdk();
+const { Agent, ConfigurationError, NetworkError } = loadCursorSdk();
 
 describe("CursorAdapterV2", () => {
   it.effect.each([
@@ -296,6 +296,42 @@ describe("CursorAdapterV2", () => {
   );
 
   it.effect.each([
+    ...([true, false] as const).map((isRetryable) => ({
+      reason: `a returned SDK error with retryable=${isRetryable}`,
+      updates: [],
+      answers: undefined,
+      wait: Effect.succeed({
+        id: "native-cursor-run",
+        status: "error" as const,
+        error: { message: "Connection stalled", code: "connection_stalled", isRetryable },
+      }),
+      failure: {
+        class: "provider_error",
+        message: "Connection stalled",
+        code: "connection_stalled",
+        retryable: isRetryable,
+      },
+    })),
+    ...([true, false] as const).map((isRetryable) => ({
+      reason: `the SDK network failure with retryable=${isRetryable}`,
+      updates: [],
+      answers: undefined,
+      wait: Effect.fail(
+        new CursorAgentSdk.CursorAgentSdkRunnerError({
+          method: "run.wait",
+          cause: new NetworkError("Connection stalled", {
+            code: "connection_stalled",
+            isRetryable,
+          }),
+        }),
+      ),
+      failure: {
+        class: "transport_error",
+        message: "Cursor Agent SDK run.wait failed: Connection stalled (connection_stalled)",
+        code: "connection_stalled",
+        retryable: isRetryable,
+      },
+    })),
     {
       reason: "the SDK's detailed plan usage limit code",
       wait: Effect.succeed({
@@ -510,6 +546,10 @@ describe("CursorAdapterV2", () => {
       assert.equal(terminal?.status, failure === null ? "completed" : "failed");
       assert.equal(terminal?.failure?.class, failure?.class);
       assert.equal(terminal?.failure?.message, failure?.message);
+      if (failure !== null && "retryable" in failure) {
+        assert.equal(terminal?.failure?.retryable, failure.retryable);
+        assert.equal(terminal?.failure?.code, failure.code);
+      }
       if (answers !== undefined) {
         assert.deepEqual(
           events.flatMap((event) =>

packages/provider-cursor/src/server/adapter.ts

@@ -2542,6 +2542,7 @@ export const makeCursorAdapterV2 = Effect.fn("makeCursorAdapterV2")(function* (
                               transportFailure === undefined
                                 ? makeProviderFailure({
                                     cause: result.error,
+                                    ...CursorAgentSdk.cursorSdkFailureMetadata(result.error),
                                     // makeProviderFailure never reads a cause's own text.
                                     message: result.error?.message,
                                     class: CursorAgentSdk.isCursorUsageLimitError(result.error)
@@ -2569,6 +2570,7 @@ export const makeCursorAdapterV2 = Effect.fn("makeCursorAdapterV2")(function* (
                         : {
                             failure: makeProviderFailure({
                               cause,
+                              ...CursorAgentSdk.cursorSdkFailureMetadata(cause),
                               message: CursorAgentSdk.isCursorAgentSdkRunnerError(cause)
                                 ? CursorAgentSdk.cursorSdkFailureMessage(cause)
                                 : undefined,