feat(agents): default codex transport to websocket-first

src/agents/pi-embedded-runner-extraparams.test.ts

@@ -490,6 +490,160 @@ describe("applyExtraParamsToAgent", () => {
     });
   });
 
+  it("passes configured websocket transport through stream options", () => {
+    const { calls, agent } = createOptionsCaptureAgent();
+    const cfg = {
+      agents: {
+        defaults: {
+          models: {
+            "openai-codex/gpt-5.3-codex": {
+              params: {
+                transport: "websocket",
+              },
+            },
+          },
+        },
+      },
+    };
+
+    applyExtraParamsToAgent(agent, cfg, "openai-codex", "gpt-5.3-codex");
+
+    const model = {
+      api: "openai-codex-responses",
+      provider: "openai-codex",
+      id: "gpt-5.3-codex",
+    } as Model<"openai-codex-responses">;
+    const context: Context = { messages: [] };
+    void agent.streamFn?.(model, context, {});
+
+    expect(calls).toHaveLength(1);
+    expect(calls[0]?.transport).toBe("websocket");
+  });
+
+  it("defaults Codex transport to auto (WebSocket-first)", () => {
+    const { calls, agent } = createOptionsCaptureAgent();
+
+    applyExtraParamsToAgent(agent, undefined, "openai-codex", "gpt-5.3-codex");
+
+    const model = {
+      api: "openai-codex-responses",
+      provider: "openai-codex",
+      id: "gpt-5.3-codex",
+    } as Model<"openai-codex-responses">;
+    const context: Context = { messages: [] };
+    void agent.streamFn?.(model, context, {});
+
+    expect(calls).toHaveLength(1);
+    expect(calls[0]?.transport).toBe("auto");
+  });
+
+  it("does not set transport defaults for non-Codex providers", () => {
+    const { calls, agent } = createOptionsCaptureAgent();
+
+    applyExtraParamsToAgent(agent, undefined, "openai", "gpt-5");
+
+    const model = {
+      api: "openai-responses",
+      provider: "openai",
+      id: "gpt-5",
+    } as Model<"openai-responses">;
+    const context: Context = { messages: [] };
+    void agent.streamFn?.(model, context, {});
+
+    expect(calls).toHaveLength(1);
+    expect(calls[0]?.transport).toBeUndefined();
+  });
+
+  it("allows forcing Codex transport to SSE", () => {
+    const { calls, agent } = createOptionsCaptureAgent();
+    const cfg = {
+      agents: {
+        defaults: {
+          models: {
+            "openai-codex/gpt-5.3-codex": {
+              params: {
+                transport: "sse",
+              },
+            },
+          },
+        },
+      },
+    };
+
+    applyExtraParamsToAgent(agent, cfg, "openai-codex", "gpt-5.3-codex");
+
+    const model = {
+      api: "openai-codex-responses",
+      provider: "openai-codex",
+      id: "gpt-5.3-codex",
+    } as Model<"openai-codex-responses">;
+    const context: Context = { messages: [] };
+    void agent.streamFn?.(model, context, {});
+
+    expect(calls).toHaveLength(1);
+    expect(calls[0]?.transport).toBe("sse");
+  });
+
+  it("lets runtime options override configured transport", () => {
+    const { calls, agent } = createOptionsCaptureAgent();
+    const cfg = {
+      agents: {
+        defaults: {
+          models: {
+            "openai-codex/gpt-5.3-codex": {
+              params: {
+                transport: "websocket",
+              },
+            },
+          },
+        },
+      },
+    };
+
+    applyExtraParamsToAgent(agent, cfg, "openai-codex", "gpt-5.3-codex");
+
+    const model = {
+      api: "openai-codex-responses",
+      provider: "openai-codex",
+      id: "gpt-5.3-codex",
+    } as Model<"openai-codex-responses">;
+    const context: Context = { messages: [] };
+    void agent.streamFn?.(model, context, { transport: "sse" });
+
+    expect(calls).toHaveLength(1);
+    expect(calls[0]?.transport).toBe("sse");
+  });
+
+  it("falls back to Codex default transport when configured value is invalid", () => {
+    const { calls, agent } = createOptionsCaptureAgent();
+    const cfg = {
+      agents: {
+        defaults: {
+          models: {
+            "openai-codex/gpt-5.3-codex": {
+              params: {
+                transport: "udp",
+              },
+            },
+          },
+        },
+      },
+    };
+
+    applyExtraParamsToAgent(agent, cfg, "openai-codex", "gpt-5.3-codex");
+
+    const model = {
+      api: "openai-codex-responses",
+      provider: "openai-codex",
+      id: "gpt-5.3-codex",
+    } as Model<"openai-codex-responses">;
+    const context: Context = { messages: [] };
+    void agent.streamFn?.(model, context, {});
+
+    expect(calls).toHaveLength(1);
+    expect(calls[0]?.transport).toBe("auto");
+  });
+
   it("disables prompt caching for non-Anthropic Bedrock models", () => {
     const { calls, agent } = createOptionsCaptureAgent();