fix(ai): keep stateless hosted tool results and tolerate WS keepalives (#44488)

packages/ai/src/protocols/open-responses-channel.ts

@@ -112,6 +112,8 @@ const driver = (options: Options, body: string): WebSocketChannelDriver => {
           responseID = created
           return { type: "frame", frame }
         }
+        // Keepalives carry no response state and may arrive before response.created.
+        if (event.type === "keepalive") return { type: "frame", frame }
         if (!responseID)
           return yield* ProviderShared.eventError(
             options.id,

packages/ai/src/protocols/open-responses.ts

@@ -582,8 +582,13 @@ const lowerMessages = Effect.fn("OpenResponses.lowerMessages")(function* (reques
           flushText()
           const id = itemID(part.providerMetadata, providerMetadataKey)
           if (store !== false && id && !hostedToolReferences.has(id)) input.push({ type: "item_reference", id })
-          if (store === false && part.result.type === "content") {
-            const content: ReadonlyArray<Content> = part.result.value
+          if (store === false) {
+            // The server is not storing this exchange, so the tool outcome has to
+            // travel in the input. Non-content results degrade to their text form.
+            const content: ReadonlyArray<Content> =
+              part.result.type === "content"
+                ? part.result.value
+                : [{ type: "text", text: ProviderShared.toolResultText(part) }]
             input.push({
               role: "user",
               content: yield* Effect.forEach(content, (item) =>

packages/ai/test/provider/openai-responses.test.ts

@@ -401,6 +401,38 @@ describe("OpenAI Responses route", () => {
     }),
   )
 
+  it.effect("tolerates keepalive frames before response.created", () =>
+    Effect.gen(function* () {
+      const webSocket = WebSocketTransport.makeDirect({
+        open: () =>
+          Effect.succeed({
+            sendText: () => Effect.void,
+            messages: Stream.fromArray([
+              ProviderShared.encodeJson({ type: "keepalive", sequence_number: 0 }),
+              ProviderShared.encodeJson({ type: "response.created", response: { id: "resp_alive" } }),
+              ProviderShared.encodeJson({
+                type: "response.completed",
+                response: { id: "resp_alive", usage: { input_tokens: 1, output_tokens: 1 } },
+              }),
+            ]),
+            close: Effect.void,
+          }),
+      })
+      const deps = Layer.succeed(
+        RequestExecutor.Service,
+        RequestExecutor.Service.of({ execute: () => Effect.die("unexpected HTTP request") }),
+      )
+      const model = OpenAI.configure({ baseURL: "https://api.openai.test/v1/", apiKey: "test" }).responses(
+        "gpt-4.1-mini",
+      )
+
+      const response = yield* LLMClient.generate(LLM.request({ model, prompt: "hi" }), { webSocket }).pipe(
+        Effect.provide(LLMClient.layer.pipe(Layer.provide(deps))),
+      )
+      expect(response.finishReason?.normalized).toBe("stop")
+    }),
+  )
+
   it.effect("continues a tool call with only the new tool output", () =>
     Effect.gen(function* () {
       const firstRequest = {
@@ -2279,6 +2311,44 @@ describe("OpenAI Responses route", () => {
     }),
   )
 
+  it.effect("continues stateless hosted tool results with their text form", () =>
+    Effect.gen(function* () {
+      const prepared = yield* compileRequest(
+        LLM.request({
+          model,
+          messages: [
+            Message.user("Search."),
+            Message.assistant([
+              ToolCallPart.make({
+                id: "ws_1",
+                name: "web_search",
+                input: { query: "effect 4" },
+                providerExecuted: true,
+                providerMetadata: { openai: { itemId: "ws_1" } },
+              }),
+              {
+                type: "tool-result",
+                id: "ws_1",
+                name: "web_search",
+                result: { type: "json", value: { type: "web_search_call", id: "ws_1", status: "completed" } },
+                providerExecuted: true,
+                providerMetadata: { openai: { itemId: "ws_1" } },
+              },
+            ]),
+            Message.user("Continue."),
+          ],
+          providerOptions: { store: false },
+        }),
+      )
+
+      expect(prepared.body.input).toEqual([
+        { role: "user", content: [{ type: "input_text", text: "Search." }] },
+        { role: "user", content: [{ type: "input_text", text: '{"type":"web_search_call","id":"ws_1","status":"completed"}' }] },
+        { role: "user", content: [{ type: "input_text", text: "Continue." }] },
+      ])
+    }),
+  )
+
   it.effect("continues stateless hosted image generation with the generated image", () =>
     Effect.gen(function* () {
       const imageTool = OpenAI.imageGeneration({ action: "edit" })