fix: retry transient Gemini failures

apps/web/src/agent/providers/__tests__/gemini.test.ts

@@ -574,4 +574,42 @@ describe("GeminiAdapter.chat()", () => {
 		expect(callArgs.tools).toBeDefined();
 		expect(callArgs.tools[0].functionDeclarations).toHaveLength(1);
 	});
+
+	test("retries transient provider failures before returning content", async () => {
+		const providerError = Object.assign(new Error("Service Unavailable"), {
+			status: 503,
+		});
+		mockGenerateContent
+			.mockRejectedValueOnce(providerError)
+			.mockRejectedValueOnce(providerError)
+			.mockResolvedValueOnce(makeGeminiResponse({ text: "Recovered" }));
+
+		const adapter = new GeminiAdapter(TEST_CONFIG);
+		const result = await adapter.chat({
+			messages: [makeChatMessage("user", "Hi")],
+			systemPrompt: "",
+			tools: [],
+		});
+
+		expect(result.content).toBe("Recovered");
+		expect(mockGenerateContent).toHaveBeenCalledTimes(3);
+	});
+
+	test("does not retry non-transient provider failures", async () => {
+		const providerError = Object.assign(new Error("Bad request"), {
+			status: 400,
+		});
+		mockGenerateContent.mockRejectedValueOnce(providerError);
+
+		const adapter = new GeminiAdapter(TEST_CONFIG);
+		await expect(
+			adapter.chat({
+				messages: [makeChatMessage("user", "Hi")],
+				systemPrompt: "",
+				tools: [],
+			}),
+		).rejects.toThrow("Bad request");
+
+		expect(mockGenerateContent).toHaveBeenCalledTimes(1);
+	});
 });

apps/web/src/agent/providers/gemini.ts

@@ -27,6 +27,51 @@ const TYPE_MAP: Record<string, SchemaType> = {
 	object: SchemaType.OBJECT,
 };
 
+const GEMINI_MAX_ATTEMPTS = 5;
+const GEMINI_RETRY_BASE_DELAY_MS = process.env.NODE_ENV === "test" ? 0 : 1000;
+const GEMINI_RETRYABLE_STATUSES = new Set([429, 500, 502, 503, 504]);
+
+function getProviderStatus(error: unknown): number | null {
+	const status = (error as { status?: unknown })?.status;
+	if (typeof status === "number") return status;
+
+	const message = error instanceof Error ? error.message : String(error);
+	const match = message.match(/\[(\d{3})\s/);
+	return match ? Number(match[1]) : null;
+}
+
+function isRetryableProviderError(error: unknown): boolean {
+	const status = getProviderStatus(error);
+	return status !== null && GEMINI_RETRYABLE_STATUSES.has(status);
+}
+
+function wait(ms: number): Promise<void> {
+	return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function withGeminiRetry<T>(operation: () => Promise<T>): Promise<T> {
+	let lastError: unknown;
+
+	for (let attempt = 1; attempt <= GEMINI_MAX_ATTEMPTS; attempt++) {
+		try {
+			return await operation();
+		} catch (error) {
+			lastError = error;
+
+			if (attempt === GEMINI_MAX_ATTEMPTS || !isRetryableProviderError(error)) {
+				throw error;
+			}
+
+			const backoffMs = GEMINI_RETRY_BASE_DELAY_MS * 2 ** (attempt - 1);
+			const jitterMs =
+				GEMINI_RETRY_BASE_DELAY_MS === 0 ? 0 : Math.random() * 250;
+			await wait(backoffMs + jitterMs);
+		}
+	}
+
+	throw lastError;
+}
+
 /**
  * Converts internal ChatMessages into Gemini Content[].
  *
@@ -291,7 +336,9 @@ export class GeminiAdapter implements ProviderAdapter {
 			request.tools = [{ functionDeclarations }];
 		}
 
-		const result = await this.model.generateContent(request);
+		const result = await withGeminiRetry(() =>
+			this.model.generateContent(request),
+		);
 		return fromGeminiResponse(result);
 	}
 }