fix(openai): share responses transport defaults

extensions/openai/openai-codex-provider.ts

@@ -28,6 +28,7 @@ import { buildOpenAIReplayPolicy } from "./replay-policy.js";
 import {
   buildOpenAISyntheticCatalogEntry,
   cloneFirstTemplateModel,
+  defaultOpenAIResponsesExtraParams,
   findCatalogTemplate,
   isOpenAIApiBaseUrl,
   isOpenAICodexBaseUrl,
@@ -336,16 +337,7 @@ export function buildOpenAICodexProviderPlugin(): ProviderPlugin {
       return id === OPENAI_CODEX_GPT_54_MODEL_ID || id === OPENAI_CODEX_GPT_54_PRO_MODEL_ID;
     },
     buildReplayPolicy: buildOpenAIReplayPolicy,
-    prepareExtraParams: (ctx) => {
-      const transport = ctx.extraParams?.transport;
-      if (transport === "auto" || transport === "sse" || transport === "websocket") {
-        return ctx.extraParams;
-      }
-      return {
-        ...ctx.extraParams,
-        transport: "auto",
-      };
-    },
+    prepareExtraParams: (ctx) => defaultOpenAIResponsesExtraParams(ctx.extraParams),
     ...OPENAI_RESPONSES_STREAM_HOOKS,
     resolveTransportTurnState: (ctx) => resolveOpenAITransportTurnState(ctx),
     resolveWebSocketSessionPolicy: (ctx) => resolveOpenAIWebSocketSessionPolicy(ctx),

extensions/openai/openai-provider.test.ts

@@ -353,6 +353,51 @@ describe("buildOpenAIProvider", () => {
     expect(result.payload.reasoning).toEqual({ effort: "none" });
   });
 
+  it("preserves explicit OpenAI responses transport and warmup overrides", () => {
+    const provider = buildOpenAIProvider();
+
+    const explicit = {
+      transport: "websocket",
+      openaiWsWarmup: false,
+      fastMode: true,
+    };
+
+    expect(
+      provider.prepareExtraParams?.({
+        provider: "openai",
+        modelId: "gpt-5.4",
+        extraParams: explicit,
+      } as never),
+    ).toBe(explicit);
+  });
+
+  it("defaults Codex responses transport without forcing warmup flags", () => {
+    const provider = buildOpenAICodexProviderPlugin();
+
+    expect(
+      provider.prepareExtraParams?.({
+        provider: "openai-codex",
+        modelId: "gpt-5.4",
+        extraParams: { effort: "high" },
+      } as never),
+    ).toEqual({
+      effort: "high",
+      transport: "auto",
+    });
+
+    const explicit = {
+      transport: "sse",
+      openaiWsWarmup: false,
+    };
+    expect(
+      provider.prepareExtraParams?.({
+        provider: "openai-codex",
+        modelId: "gpt-5.4",
+        extraParams: explicit,
+      } as never),
+    ).toBe(explicit);
+  });
+
   it("owns Azure OpenAI reasoning compatibility without forcing OpenAI transport defaults", () => {
     const provider = buildOpenAIProvider();
     const wrap = provider.wrapStreamFn;

extensions/openai/openai-provider.ts

@@ -16,6 +16,7 @@ import { buildOpenAIReplayPolicy } from "./replay-policy.js";
 import {
   buildOpenAISyntheticCatalogEntry,
   cloneFirstTemplateModel,
+  defaultOpenAIResponsesExtraParams,
   findCatalogTemplate,
   isOpenAIApiBaseUrl,
   matchesExactOrPrefix,
@@ -222,20 +223,8 @@ export function buildOpenAIProvider(): ProviderPlugin {
         ? { api: "openai-responses", baseUrl }
         : undefined,
     buildReplayPolicy: buildOpenAIReplayPolicy,
-    prepareExtraParams: (ctx) => {
-      const transport = ctx.extraParams?.transport;
-      const hasSupportedTransport =
-        transport === "auto" || transport === "sse" || transport === "websocket";
-      const hasExplicitWarmup = typeof ctx.extraParams?.openaiWsWarmup === "boolean";
-      if (hasSupportedTransport && hasExplicitWarmup) {
-        return ctx.extraParams;
-      }
-      return {
-        ...ctx.extraParams,
-        ...(hasSupportedTransport ? {} : { transport: "auto" }),
-        ...(hasExplicitWarmup ? {} : { openaiWsWarmup: true }),
-      };
-    },
+    prepareExtraParams: (ctx) =>
+      defaultOpenAIResponsesExtraParams(ctx.extraParams, { openaiWsWarmup: true }),
     ...OPENAI_RESPONSES_STREAM_HOOKS,
     matchesContextOverflowError: ({ errorMessage }) =>
       /content_filter.*(?:prompt|input).*(?:too long|exceed)/i.test(errorMessage),

extensions/openai/shared.ts

@@ -50,6 +50,30 @@ export function isOpenAICodexBaseUrl(baseUrl?: string): boolean {
   return /^https?:\/\/chatgpt\.com\/backend-api\/?$/i.test(trimmed);
 }
 
+function hasSupportedOpenAIResponsesTransport(
+  transport: unknown,
+): transport is "auto" | "sse" | "websocket" {
+  return transport === "auto" || transport === "sse" || transport === "websocket";
+}
+
+export function defaultOpenAIResponsesExtraParams(
+  extraParams: Record<string, unknown> | undefined,
+  options?: { openaiWsWarmup?: boolean },
+): Record<string, unknown> | undefined {
+  const hasSupportedTransport = hasSupportedOpenAIResponsesTransport(extraParams?.transport);
+  const hasExplicitWarmup = typeof extraParams?.openaiWsWarmup === "boolean";
+  const shouldDefaultWarmup = options?.openaiWsWarmup === true;
+  if (hasSupportedTransport && (!shouldDefaultWarmup || hasExplicitWarmup)) {
+    return extraParams;
+  }
+
+  return {
+    ...extraParams,
+    ...(hasSupportedTransport ? {} : { transport: "auto" }),
+    ...(shouldDefaultWarmup && !hasExplicitWarmup ? { openaiWsWarmup: true } : {}),
+  };
+}
+
 export function buildOpenAISyntheticCatalogEntry(
   template: ReturnType<typeof findCatalogTemplate>,
   entry: {