feat(ai): allowed custom idle timeout for openai responses streams

- Pass `streamIdleTimeoutMs` from model compatibility settings to the streaming logic.
- Update catalog definitions for Sakana models to include a 300,000ms idle timeout.
- Add a test case to verify that the streaming client honors the model-defined idle timeout.

packages/ai/src/providers/openai-responses.ts

@@ -436,7 +436,8 @@ const streamOpenAIResponsesOnce = (
 					? buildOpenAIResponsesChainedParams(params, trailingScaffoldingItems, chainState)
 					: { params };
 			sentPreviousResponseId = chained.previousResponseId;
-			const idleTimeoutMs = options?.streamIdleTimeoutMs ?? getOpenAIStreamIdleTimeoutMs();
+			const idleTimeoutMs =
+				options?.streamIdleTimeoutMs ?? getOpenAIStreamIdleTimeoutMs(model.compat.streamIdleTimeoutMs);
 			const firstEventTimeoutMs =
 				options?.streamFirstEventTimeoutMs ?? getOpenAIStreamFirstEventTimeoutMs(idleTimeoutMs);
 			const requestTimeoutMs =

packages/ai/test/openai-first-event-timeout.test.ts

@@ -790,4 +790,29 @@ describe("OpenAI-family first-event timeouts", () => {
 			{ type: "text", text: "Truncated output", textSignature: '{"v":1,"id":"msg_length_limited"}' },
 		]);
 	});
+
+	it("honors streamIdleTimeoutMs from model.compat for OpenAI responses streams", async () => {
+		const customResponsesModel: Model<"openai-responses"> = buildModel({
+			id: "fugu-test",
+			name: "Fugu Test",
+			api: "openai-responses",
+			provider: "sakana",
+			baseUrl: "https://api.sakana.ai/v1",
+			reasoning: true,
+			input: ["text"],
+			cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+			contextWindow: 128000,
+			maxTokens: 16384,
+			compat: { streamIdleTimeoutMs: 20 },
+		});
+
+		const fetchMock = () => Promise.resolve(createNoProgressOpenAIResponsesStream(undefined));
+		const result = await streamOpenAIResponses(customResponsesModel, baseContext(), {
+			apiKey: "test-key",
+			fetch: fetchMock as any,
+		}).result();
+
+		expect(result.stopReason).toBe("error");
+		expect(result.errorMessage).toBe("OpenAI responses stream stalled while waiting for the next event");
+	});
 });

packages/ai/test/proxy.test.ts

@@ -1,6 +1,11 @@
 import { afterEach, beforeEach, describe, expect, it } from "bun:test";
 import type { FetchImpl } from "@oh-my-pi/pi-ai/types";
-import { getProxyForProvider, isLocalOrMetadataHost, shouldBypassProxy, wrapFetchForProxy } from "@oh-my-pi/pi-ai/utils/proxy";
+import {
+	getProxyForProvider,
+	isLocalOrMetadataHost,
+	shouldBypassProxy,
+	wrapFetchForProxy,
+} from "@oh-my-pi/pi-ai/utils/proxy";
 
 const PROXY = "http://127.0.0.1:24560";
 

packages/catalog/src/compat/openai.ts

@@ -535,6 +535,7 @@ export function buildOpenAIResponsesCompat(spec: OpenAIResponsesSpecLike): Resol
 		emptyLengthFinishIsContextError: spec.provider === "ollama",
 		usesOpenAIToolCallIdLimit: spec.provider === "openai",
 		promptCacheSessionHeader: spec.provider === "xai-oauth" ? "x-grok-conv-id" : undefined,
+		streamIdleTimeoutMs: spec.compat?.streamIdleTimeoutMs,
 	};
 	applyCompatOverrides(compat, spec.compat);
 	if (spec.compat?.reasoningDisableMode === undefined) {

packages/catalog/src/models.json

@@ -69272,7 +69272,8 @@
 				}
 			},
 			"compat": {
-				"includeEncryptedReasoning": false
+				"includeEncryptedReasoning": false,
+				"streamIdleTimeoutMs": 300000
 			}
 		},
 		"fugu-ultra": {
@@ -69304,7 +69305,8 @@
 				}
 			},
 			"compat": {
-				"includeEncryptedReasoning": false
+				"includeEncryptedReasoning": false,
+				"streamIdleTimeoutMs": 300000
 			}
 		},
 		"fugu-ultra-20260615": {
@@ -69336,7 +69338,8 @@
 				}
 			},
 			"compat": {
-				"includeEncryptedReasoning": false
+				"includeEncryptedReasoning": false,
+				"streamIdleTimeoutMs": 300000
 			}
 		}
 	},

packages/catalog/src/provider-models/openai-compat.ts

@@ -2534,6 +2534,7 @@ const SAKANA_FUGU_THINKING: ThinkingConfig = {
 };
 const SAKANA_RESPONSES_COMPAT: ModelSpec<"openai-responses">["compat"] = {
 	includeEncryptedReasoning: false,
+	streamIdleTimeoutMs: 300_000,
 };
 
 function normalizeSakanaBaseUrl(baseUrl: string | undefined): string {

packages/catalog/src/types.ts

@@ -534,6 +534,7 @@ export interface ResolvedOpenAIResponsesCompat extends ResolvedOpenAISharedCompa
 	supportsImageDetailOriginal: boolean;
 	requiresJuiceZeroHack: boolean;
 	supportsObfuscationOptOut: boolean;
+	streamIdleTimeoutMs?: number;
 }
 
 /**