[WRONG BRANCH] fix(claude): avoid leaking main ChatGPT credential to non-canonical openai-responses providers

src/server/claude-messages.ts

@@ -27,6 +27,7 @@ import { clearableDeadline, idleDeadline } from "../lib/abort";
 import { estimateTokens } from "../lib/token-estimate";
 import { NoEligiblePolicyCandidateError, routeModel } from "../router";
 import { evidenceFromBody } from "../routing/request-evidence";
+import { isCanonicalOpenAiForwardProvider } from "../providers/openai-tiers";
 import { resolveWireProtocolOverride } from "./adapter-resolve";
 import type { OcxConfig } from "../types";
 import { readJsonRequestBody } from "./request-decompress";
@@ -628,11 +629,17 @@ async function handleClaudeMessagesWithBudget(
   // bodies: it 400s on sampling params ("Unsupported parameter: max_output_tokens",
   // verified live 2026-07-11). Strip them for that route; routed providers keep them.
   let nativeRoute = false;
+  let allowMainAccountEnrichment = false;
   try {
     const route = routeModel(config, internalBody.model as string, evidenceFromBody(internalBody));
     // Settle the wire once so the sampling decision below reads the effective
     // adapter rather than the provider-wide default (#404).
     route.provider = resolveWireProtocolOverride(route.providerName, route.modelId, route.provider, "anthropic");
+    // Main-account headers may reach an openai-responses forward destination verbatim.
+    // Only the canonical ChatGPT destination is allowed to receive that credential;
+    // other adapters replace it with their own auth before the upstream request.
+    allowMainAccountEnrichment = route.provider.adapter !== "openai-responses"
+      || isCanonicalOpenAiForwardProvider(route.provider);
     logCtx.routeDecision = route.routeDecision;
     if (route.provider.adapter === "openai-responses") {
       nativeRoute = true;
@@ -685,7 +692,7 @@ async function handleClaudeMessagesWithBudget(
   // native replays have no caller ChatGPT credential. This enrichment is optional:
   // auth-context later rejects a real physical-main selection, while routed/pool
   // traffic continues without reading native credentials during a fence/recovery.
-  if (tryClaimNativeMainProfileForTurn(logIds?.turnAdmissionLease)) {
+  if (allowMainAccountEnrichment && tryClaimNativeMainProfileForTurn(logIds?.turnAdmissionLease)) {
     const { getMainAccountToken } = await import("../codex/main-account");
     const token = getMainAccountToken();
     if (token) {

tests/claude-messages-endpoint.test.ts

@@ -620,6 +620,56 @@ test("native openai-responses route carries prompt_cache_key + synthesized sessi
   }
 });
 
+test("custom forward openai-responses route never receives the main ChatGPT credential", async () => {
+  writeFileSync(join(isolatedCodexHome!.path, "auth.json"), JSON.stringify({
+    tokens: { access_token: "main-secret-must-not-leave", account_id: "main-account-must-not-leave" },
+  }));
+  const captured: Array<{ authorization: string | null; accountId: string | null }> = [];
+  const upstream = Bun.serve({
+    port: 0,
+    fetch(req) {
+      captured.push({
+        authorization: req.headers.get("authorization"),
+        accountId: req.headers.get("chatgpt-account-id"),
+      });
+      return new Response([
+        'event: response.created\ndata: {"response":{"id":"resp_1","status":"in_progress"}}\n\n',
+        'event: response.completed\ndata: {"response":{"status":"completed","usage":{"input_tokens":1,"output_tokens":1}}}\n\n',
+      ].join(""), { headers: { "content-type": "text/event-stream" } });
+    },
+  });
+  saveConfig({
+    port: 0,
+    defaultProvider: "custom",
+    providers: {
+      custom: {
+        adapter: "openai-responses",
+        baseUrl: `${upstream.url.toString().replace(/\/$/, "")}/v1`,
+        authMode: "forward",
+        allowPrivateNetwork: true,
+      },
+    },
+  } as OcxConfig);
+  const server = startServer(0);
+  try {
+    const response = await fetch(new URL("/v1/messages", server.url), {
+      method: "POST",
+      headers: { "content-type": "application/json", authorization: "Bearer claude-placeholder" },
+      body: JSON.stringify({
+        model: "custom/gpt-test",
+        max_tokens: 16,
+        messages: [{ role: "user", content: "hi" }],
+      }),
+    });
+    expect(response.status).toBe(200);
+    await response.text();
+    expect(captured).toEqual([{ authorization: null, accountId: null }]);
+  } finally {
+    await server.stop(true);
+    upstream.stop(true);
+  }
+});
+
 test("Claude replay owns optional main enrichment while routed work survives drain and recovery", async () => {
   resetLifecycleDrainStateForTests();
   writeFileSync(join(isolatedCodexHome!.path, "auth.json"), JSON.stringify({