fix(agentrouter): infer protocol from client endpoint

fix(agentrouter): infer protocol from client endpoint

- /v1/responses resolves AgentRouter as openai-responses
- /v1/chat/completions resolves AgentRouter as openai
- /v1/messages resolves AgentRouter as claude
- Per-request protocol and credential cloning (no SQLite mutation)
- Codex 0.146.0 and Claude Code 2.1.220 identity alignment
- response.completed.usage.total_tokens normalization for strict Codex clients

Closes #9224

config/quality/file-size-baseline.json

@@ -177,7 +177,7 @@
     "tests/unit/account-fallback-service.test.ts": 1563,
     "tests/unit/batch_api.test.ts": 1324,
     "tests/unit/cc-compatible-provider.test.ts": 1217,
-    "tests/unit/chatcore-translation-paths.test.ts": 2769,
+    "tests/unit/chatcore-translation-paths.test.ts": 2776,
     "tests/unit/chatgpt-web.test.ts": 3148,
     "tests/unit/combo-routing-engine.test.ts": 3449,
     "tests/unit/db-migration-runner.test.ts": 1499,
@@ -342,7 +342,7 @@
     "_rebaseline_pr1043_minimax_tts": "Upstream port decolua/9router#1043 (toanalien) own growth: audioSpeech.ts 965->1061 (+96). Adds MiniMax T2A v2 TTS dispatch (handleMinimaxSpeech + hexToBytes helper) — provider entry was already in audioRegistry (format: minimax-tts) but no handler existed, falling through to the OpenAI-compatible default that fails (T2A has custom shape + hex-encoded audio + base_resp envelope). New branch sits next to the other inline provider branches (xiaomi-mimo, coqui, tortoise, aws-polly) — extracting would just create indirection. Covered by tests/unit/minimax-tts-1043.test.ts (3 tests, GREEN: success, base_resp error, invalid-hex).",
     "_rebaseline_pr4592_exclude_exhausted_auto": "Reconcile #4592 already-merged growth: combo.ts 2991->3036 (+45, terminal-status quota-cutoff exclusion in buildAutoCandidates + opt-in gate). Fast-gate PR->release does not run check:file-size.",
     "open-sse/executors/antigravity.ts": 1528,
-    "open-sse/executors/base.ts": 1562,
+    "open-sse/executors/base.ts": 1578,
     "open-sse/executors/chatgpt-web.ts": 3241,
     "open-sse/executors/codex.ts": 1534,
     "open-sse/executors/cursor.ts": 1560,
@@ -365,7 +365,7 @@
     "open-sse/services/rateLimitManager.ts": 1060,
     "open-sse/translator/response/openai-responses.ts": 1174,
     "open-sse/utils/cursorAgentProtobuf.ts": 1505,
-    "open-sse/utils/stream.ts": 2887,
+    "open-sse/utils/stream.ts": 2889,
     "src/app/(dashboard)/dashboard/HomePageClient.tsx": 1381,
     "src/app/(dashboard)/dashboard/analytics/ComboHealthTab.tsx": 1031,
     "src/app/(dashboard)/dashboard/api-manager/ApiManagerPageClient.tsx": 3117,
@@ -413,5 +413,6 @@
   "_rebaseline_2026_07_28_8860_tokenrefresh_projectid": "PR #8860 (fix/antigravity-projectid-centralized) own test growth: tests/unit/token-refresh-service.test.ts 1311->1378 (+67 = 4 cases covering projectId discovery on the tokenRefresh.ts path — the Dashboard/health-check refresh route, which #8842 did not reach since that fixed the executor path). Covered by the same file.",
   "_rebaseline_2026_07_28_8861_xiaomi_token_plan": "PR #8861 (feat/xiaomi-token-plan-protocol-selector) own growth: EditConnectionModal.tsx 1283->1316 (+33 = the per-connection API-protocol selector field) and open-sse/executors/base.ts 1540->1562 (+22 = alternate-format resolution at the existing buildUrl/headers chokepoint). Both are irreducible wiring at existing call sites.",
   "_rebaseline_2026_07_28_8863_firefly_detail_level": "PR #8863 (fix/adobe-firefly-gpt-detail-level-max) own growth: adobeFireflyClient.ts 2317->2322 (+5 = gpt-image detailLevel defaulting to maximal at the existing payload-build site). Covered by tests/unit/adobe-firefly.test.ts.",
-  "_rebaseline_2026_07_29_8281_home_quickstart_prefetch": "Release v3.8.49 base-red fix (no PR — captain sweep): src/app/(dashboard)/dashboard/HomePageClient.tsx 1377->1381 (+4). #8292 added prefetch={false} to the sidebar but left /home's five quick-start Links prefetching, so first paint still fired 12 speculative RSC requests — caught by navigation.spec.ts only after the e2e helper bug (APP_ROUTE_PATTERN missing /home) was repaired in the same cycle. Growth is the five prefetch attributes; it was offset first by extracting the repeated className literals (INLINE_LINK x4, DOCS_LINK x1), which collapsed five wrapped <Link> blocks back to one line each — a naive fix measured 1391. Guard: tests/unit/sidebar-prefetch-policy-8281.test.ts."
+  "_rebaseline_2026_07_29_8281_home_quickstart_prefetch": "Release v3.8.49 base-red fix (no PR — captain sweep): src/app/(dashboard)/dashboard/HomePageClient.tsx 1377->1381 (+4). #8292 added prefetch={false} to the sidebar but left /home's five quick-start Links prefetching, so first paint still fired 12 speculative RSC requests — caught by navigation.spec.ts only after the e2e helper bug (APP_ROUTE_PATTERN missing /home) was repaired in the same cycle. Growth is the five prefetch attributes; it was offset first by extracting the repeated className literals (INLINE_LINK x4, DOCS_LINK x1), which collapsed five wrapped <Link> blocks back to one line each — a naive fix measured 1391. Guard: tests/unit/sidebar-prefetch-policy-8281.test.ts.",
+  "_rebaseline_2026_08_02_v3850_agentrouter_responses": "Release v3.8.50 AgentRouter/Codex compatibility reconciliation. open-sse/executors/base.ts 1562->1578: #9190 wires AgentRouter's selected Claude/OpenAI/Responses protocol through the existing executor URL, auth, identity-header and fingerprint chokepoints; the reusable alternate resolver remains outside base.ts. open-sse/utils/stream.ts 2887->2889: #9213 evaluates Responses ID and usage normalization independently so response.completed always receives finite usage.total_tokens instead of short-circuiting after an ID rewrite. tests/unit/chatcore-translation-paths.test.ts 2769->2776: #9191 updates the existing Claude-Code bridge assertions for the dynamic AgentRouter wire image. PR #9224 offsets its own chatCore growth by extracting the AgentRouter protocol decisions into chatCore/agentRouterProtocol.ts, leaving chatCore below its frozen ceiling. Covered by agentrouter executor/chatCore protocol tests, chatcore translation-path tests, and responses-commentary-passthrough tests."
 }

open-sse/handlers/chatCore.ts

@@ -71,6 +71,7 @@ import { checkHeapPressureGuard } from "../utils/heapPressure.ts";
 import { normalizeHeaders } from "../utils/headers.ts";
 import { resolveChatCoreRequestFormat } from "./chatCore/requestFormat.ts";
 import { resolveChatCoreTargetFormat } from "./chatCore/targetFormat.ts";
+import { stripStore, usesClaudeBridge } from "./chatCore/agentRouterProtocol.ts";
 import { defaultClaudeToolType } from "./chatCore/claudeToolDefaults.ts";
 import { injectSystemPrompt, injectCustomSystemPrompt } from "../services/systemPrompt.ts";
 import { translateRequest, needsTranslation } from "../translator/index.ts";
@@ -341,7 +342,6 @@ import { OMNIROUTE_RESPONSE_HEADERS } from "@/shared/constants/headers";
 import { getClaudeCodeCompatibleRequestDefaults } from "@/lib/providers/requestDefaults";
 import {
   buildClaudeCodeCompatibleRequest,
-  isClaudeCodeCompatibleProvider,
   resolveClaudeCodeCompatibleSessionId,
 } from "../services/claudeCodeCompatible.ts";
 import { setGeminiThoughtSignatureMode } from "../services/geminiThoughtSignatureStore.ts";
@@ -751,6 +751,7 @@ export async function handleChatCore({
     provider,
     resolvedModel,
     apiFormat,
+    sourceFormat,
     customModelTargetFormat,
     providerSpecificData: credentials?.providerSpecificData,
   });
@@ -1920,15 +1921,7 @@ export async function handleChatCore({
 
   let translatedBody = body;
   const isClaudePassthrough = sourceFormat === FORMATS.CLAUDE && targetFormat === FORMATS.CLAUDE;
-  // A provider may expose the Claude Code wire image as its default protocol while
+  const isClaudeCodeCompatible = usesClaudeBridge(provider, targetFormat, credentials);
-  // selecting a declared OpenAI alternate on a connection (for example AgentRouter).
-  // The bridge must follow the resolved target format, otherwise OpenAI Responses
-  // requests are rewritten to Claude Messages and upstream rejects the missing input.
-  const configuredTargetFormat = credentials?.providerSpecificData?.targetFormat;
-  const isClaudeCodeCompatible =
-    isClaudeCodeCompatibleProvider(provider) &&
-    configuredTargetFormat !== FORMATS.OPENAI &&
-    configuredTargetFormat !== FORMATS.OPENAI_RESPONSES;
   const isClaudeCodeSemanticPassthrough = isClaudeCodeSemanticPassthroughRequest({
     provider,
     sourceFormat,
@@ -2504,10 +2497,7 @@ export async function handleChatCore({
     log?.debug?.("PARAMS", `Renamed max_completion_tokens to max_tokens for ${model}`);
   }
 
-  // OpenAI's `store` parameter is not supported by most compatible providers and breaks them
+  stripStore(translatedBody, provider, targetFormat);
-  if (provider !== "openai" && "store" in translatedBody) {
-    delete translatedBody.store;
-  }
 
   // Chat clients may send stream_options.include_usage, but OpenAI Responses
   // upstreams (including Azure AI Foundry /responses) reject stream_options.

open-sse/handlers/chatCore/agentRouterProtocol.ts

@@ -0,0 +1,35 @@
+/**
+ * Per-request AgentRouter protocol decisions kept outside the chatCore orchestration god-file.
+ * AgentRouter exposes Claude Messages, OpenAI Chat, and OpenAI Responses as distinct upstream
+ * protocols, so its dynamic target format must override the connection's default Claude wire image.
+ */
+
+import { isClaudeCodeCompatibleProvider } from "../../services/claudeCodeCompatible.ts";
+import { FORMATS } from "../../translator/formats.ts";
+
+export function usesClaudeBridge(
+  provider: string,
+  targetFormat: string,
+  credentials: unknown
+): boolean {
+  const configuredTargetFormat = (
+    credentials as { providerSpecificData?: { targetFormat?: unknown } | null } | null | undefined
+  )?.providerSpecificData?.targetFormat;
+  const effectiveFormat = provider === "agentrouter" ? targetFormat : configuredTargetFormat;
+  return (
+    isClaudeCodeCompatibleProvider(provider) &&
+    effectiveFormat !== FORMATS.OPENAI &&
+    effectiveFormat !== FORMATS.OPENAI_RESPONSES
+  );
+}
+
+export function stripStore(
+  body: Record<string, unknown>,
+  provider: string,
+  targetFormat: string
+): void {
+  const supportsStore =
+    provider === "openai" ||
+    (provider === "agentrouter" && targetFormat === FORMATS.OPENAI_RESPONSES);
+  if (!supportsStore && "store" in body) delete body.store;
+}

open-sse/handlers/chatCore/executionCredentials.ts

@@ -5,8 +5,8 @@
  * Pure builder extracted from handleChatCore: derives the per-execution credentials object from the
  * resolved request context. Applies the native-Codex passthrough endpoint override, forces
  * apiType=responses (and the responses-upstream marker) for Azure AI Foundry / OCI when the model
- * routes to the OpenAI Responses format, and threads the Claude Code session id when present.
+ * routes to the OpenAI Responses format, synchronizes AgentRouter's per-request alternate protocol,
- * Side-effect-free; behaviour is byte-identical to the previous inline closure.
+ * and threads the Claude Code session id when present. Side-effect-free.
  */
 
 import { getKimiCodeStaticThinkingPolicy } from "../../config/providers/registry/kimi/coding/runtime.ts";
@@ -128,6 +128,16 @@ export function resolveExecutionCredentials(opts: {
     providerSpecificData.targetFormat = targetFormat;
   }
 
+  // AgentRouter exposes Claude, OpenAI Chat, and OpenAI Responses on distinct URLs with distinct
+  // auth schemes. Keep the executor's URL/header resolution synchronized with chatCore's resolved
+  // per-request protocol without persisting the inferred selection back to the connection.
+  if (
+    provider === "agentrouter" &&
+    (targetFormat === FORMATS.OPENAI || targetFormat === FORMATS.OPENAI_RESPONSES)
+  ) {
+    providerSpecificData.targetFormat = targetFormat;
+  }
+
   applyKimiExecutionMetadata(providerSpecificData, provider, targetFormat, modelInfo);
 
   const withApiType = {

open-sse/handlers/chatCore/targetFormat.ts

@@ -4,10 +4,11 @@
  *
  * Pure resolution of the provider alias + the upstream target format used to translate the request:
  * apiFormat==="responses" forces OpenAI Responses; otherwise the model's registry target format, then
- * the per-model custom override (#2905), then the provider default. Returns both `alias` (reused by
+ * the per-model custom override (#2905), then AgentRouter's matching inbound protocol when the
+ * connection has no explicit override, then the provider default. Returns both `alias` (reused by
  * the handler when stripping the `alias/` prefix off the upstream model id) and `targetFormat`.
- * Side-effect-free; byte-identical to the previous inline block. Sits alongside the other
+ * Side-effect-free; sits alongside the other request-setup resolvers
- * request-setup resolvers (resolveChatCoreRequestSetup / resolveChatCoreRequestFormat).
+ * (resolveChatCoreRequestSetup / resolveChatCoreRequestFormat).
  */
 
 import { PROVIDER_ID_TO_ALIAS, getModelTargetFormat } from "../../config/providerModels.ts";
@@ -18,16 +19,38 @@ export function resolveChatCoreTargetFormat(opts: {
   provider: string;
   resolvedModel: string;
   apiFormat: string | undefined;
+  sourceFormat?: string;
   customModelTargetFormat: string | undefined;
   providerSpecificData: unknown;
 }) {
-  const { provider, resolvedModel, apiFormat, customModelTargetFormat, providerSpecificData } = opts;
+  const {
+    provider,
+    resolvedModel,
+    apiFormat,
+    sourceFormat,
+    customModelTargetFormat,
+    providerSpecificData,
+  } = opts;
   const alias = PROVIDER_ID_TO_ALIAS[provider] || provider;
   const modelTargetFormat = getModelTargetFormat(alias, resolvedModel);
+  const explicitConnectionTargetFormat = (
+    providerSpecificData as { targetFormat?: unknown } | null | undefined
+  )?.targetFormat;
+  const inferredAgentRouterTargetFormat =
+    provider === "agentrouter" &&
+    !(typeof explicitConnectionTargetFormat === "string" && explicitConnectionTargetFormat) &&
+    (sourceFormat === FORMATS.OPENAI_RESPONSES ||
+      sourceFormat === FORMATS.OPENAI ||
+      sourceFormat === FORMATS.CLAUDE)
+      ? sourceFormat
+      : undefined;
   const targetFormat =
     apiFormat === "responses"
       ? FORMATS.OPENAI_RESPONSES
-      : modelTargetFormat || customModelTargetFormat || getTargetFormat(provider, providerSpecificData);
+      : modelTargetFormat ||
+        customModelTargetFormat ||
+        inferredAgentRouterTargetFormat ||
+        getTargetFormat(provider, providerSpecificData);
   return { alias, targetFormat };
 }
 

src/app/(dashboard)/dashboard/settings/components/RoutingTab.tsx

@@ -171,7 +171,7 @@ const DEFAULT_SYSTEM_TRANSFORMS_CLIENT = {
           entrypoint: "sdk-cli",
           versionFormat: "ex-machina",
           cchAlgo: "sha256-first-user",
-          buildRevision: "250",
+          buildRevision: "1f2",
         },
       ],
     },

tests/snapshots/provider/translate-path.json

@@ -28,7 +28,7 @@
       "apiKey": {
         "Accept": "text/event-stream",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.219 (external, sdk-cli)",
+        "User-Agent": "claude-cli/2.1.220 (external, sdk-cli)",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Lang": "js",
         "X-Stainless-OS": "MacOS",
@@ -47,7 +47,7 @@
       "nonStream": {
         "Accept": "application/json",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.219 (external, sdk-cli)",
+        "User-Agent": "claude-cli/2.1.220 (external, sdk-cli)",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Lang": "js",
         "X-Stainless-OS": "MacOS",
@@ -66,7 +66,7 @@
       "oauth": {
         "Accept": "text/event-stream",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.219 (external, sdk-cli)",
+        "User-Agent": "claude-cli/2.1.220 (external, sdk-cli)",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Lang": "js",
         "X-Stainless-OS": "MacOS",
@@ -874,7 +874,7 @@
         "Anthropic-Dangerous-Direct-Browser-Access": "true",
         "Anthropic-Version": "2023-06-01",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.219 (external, cli)",
+        "User-Agent": "claude-cli/2.1.220 (external, cli)",
         "X-App": "cli",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Helper-Method": "stream",
@@ -892,7 +892,7 @@
         "Anthropic-Dangerous-Direct-Browser-Access": "true",
         "Anthropic-Version": "2023-06-01",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.219 (external, cli)",
+        "User-Agent": "claude-cli/2.1.220 (external, cli)",
         "X-App": "cli",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Helper-Method": "stream",
@@ -911,7 +911,7 @@
         "Anthropic-Dangerous-Direct-Browser-Access": "true",
         "Anthropic-Version": "2023-06-01",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.219 (external, cli)",
+        "User-Agent": "claude-cli/2.1.220 (external, cli)",
         "X-App": "cli",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Helper-Method": "stream",
@@ -1153,16 +1153,16 @@
         "Authorization": "Bearer <TOK>",
         "Content-Type": "application/json",
         "Openai-Beta": "responses=experimental",
-        "User-Agent": "codex-cli/0.144.1 (<OS>; <ARCH>)",
+        "User-Agent": "codex-cli/0.146.0 (<OS>; <ARCH>)",
-        "Version": "0.144.1",
+        "Version": "0.146.0",
         "X-Codex-Beta-Features": "responses_websockets"
       },
       "nonStream": {
         "Authorization": "Bearer <TOK>",
         "Content-Type": "application/json",
         "Openai-Beta": "responses=experimental",
-        "User-Agent": "codex-cli/0.144.1 (<OS>; <ARCH>)",
+        "User-Agent": "codex-cli/0.146.0 (<OS>; <ARCH>)",
-        "Version": "0.144.1",
+        "Version": "0.146.0",
         "X-Codex-Beta-Features": "responses_websockets"
       },
       "oauth": {
@@ -1170,8 +1170,8 @@
         "Authorization": "Bearer <TOK>",
         "Content-Type": "application/json",
         "Openai-Beta": "responses=experimental",
-        "User-Agent": "codex-cli/0.144.1 (<OS>; <ARCH>)",
+        "User-Agent": "codex-cli/0.146.0 (<OS>; <ARCH>)",
-        "Version": "0.144.1",
+        "Version": "0.146.0",
         "X-Codex-Beta-Features": "responses_websockets"
       }
     },

tests/unit/agentrouter-chatcore-protocols.test.ts

@@ -22,6 +22,13 @@ function noopLog() {
   };
 }
 
+function createSseResponse(events: string[]) {
+  return new Response(`${events.join("\n\n")}\n\n`, {
+    status: 200,
+    headers: { "Content-Type": "text/event-stream" },
+  });
+}
+
 async function waitForAsyncSideEffects() {
   await new Promise((resolve) => setImmediate(resolve));
   await new Promise((resolve) => setTimeout(resolve, 20));
@@ -41,7 +48,7 @@ test.after(() => {
   fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
 });
 
-test("AgentRouter Responses connections send a native Responses body through chatCore", async () => {
+test("AgentRouter Responses requests automatically use the native Responses protocol", async () => {
   let captured: { url: string; headers: Headers; body: Record<string, unknown> } | null = null;
 
   globalThis.fetch = async (url, init = {}) => {
@@ -97,7 +104,7 @@ test("AgentRouter Responses connections send a native Responses body through cha
     },
     credentials: {
       apiKey: "test-agentrouter-key",
-      providerSpecificData: { targetFormat: "openai-responses" },
+      providerSpecificData: {},
     },
     log: noopLog(),
     clientRawRequest: {
@@ -108,18 +115,22 @@ test("AgentRouter Responses connections send a native Responses body through cha
     userAgent: "codex_cli_rs/0.146.0",
   });
 
-  assert.equal(result.success, true);
   assert.ok(captured);
-  assert.equal(captured.url, "https://agentrouter.org/v1/responses");
+  assert.equal(
+    captured.url,
+    "https://agentrouter.org/v1/responses",
+    JSON.stringify(captured.body, null, 2)
+  );
+  assert.ok("input" in captured.body, JSON.stringify(captured.body, null, 2));
+  assert.equal(result.success, true);
   assert.equal(captured.headers.get("authorization"), "Bearer test-agentrouter-key");
   assert.equal(captured.headers.get("originator"), "codex_cli_rs");
-  assert.ok("input" in captured.body);
   assert.equal("system" in captured.body, false);
   assert.equal("thinking" in captured.body, false);
   assert.equal("output_config" in captured.body, false);
 });
 
-test("AgentRouter OpenAI Chat connections keep the OpenAI request shape through chatCore", async () => {
+test("AgentRouter OpenAI Chat requests automatically use the native Chat protocol", async () => {
   let captured: { url: string; headers: Headers; body: Record<string, unknown> } | null = null;
 
   globalThis.fetch = async (url, init = {}) => {
@@ -157,7 +168,7 @@ test("AgentRouter OpenAI Chat connections keep the OpenAI request shape through
     modelInfo: { provider: "agentrouter", model: "gpt-5.6-sol", extendedContext: false },
     credentials: {
       apiKey: "test-agentrouter-key",
-      providerSpecificData: { targetFormat: "openai" },
+      providerSpecificData: {},
     },
     log: noopLog(),
     clientRawRequest: {
@@ -180,7 +191,7 @@ test("AgentRouter OpenAI Chat connections keep the OpenAI request shape through
   assert.equal("output_config" in captured.body, false);
 });
 
-test("AgentRouter default Claude connections retain the Claude Code bridge through chatCore", async () => {
+test("AgentRouter Anthropic requests automatically use the native Messages protocol", async () => {
   let captured: { url: string; headers: Headers; body: Record<string, unknown> } | null = null;
 
   globalThis.fetch = async (url, init = {}) => {
@@ -220,11 +231,11 @@ test("AgentRouter default Claude connections retain the Claude Code bridge throu
     credentials: { apiKey: "test-agentrouter-key", providerSpecificData: {} },
     log: noopLog(),
     clientRawRequest: {
-      endpoint: "/v1/chat/completions",
+      endpoint: "/v1/messages",
       body: structuredClone(body),
       headers: new Headers({ accept: "application/json" }),
     },
-    userAgent: "codex_cli_rs/0.146.0",
+    userAgent: "claude-cli/2.1.19",
   });
 
   assert.equal(result.success, true);
@@ -237,3 +248,217 @@ test("AgentRouter default Claude connections retain the Claude Code bridge throu
   assert.equal(captured.body.thinking.type, "adaptive");
   assert.equal(captured.body.output_config.effort, "xhigh");
 });
+
+test("AgentRouter Responses streaming stays native without a connection protocol override", async () => {
+  let captured: { url: string; headers: Headers; body: Record<string, unknown> } | null = null;
+
+  globalThis.fetch = async (url, init = {}) => {
+    captured = {
+      url: String(url),
+      headers: new Headers(init.headers),
+      body: JSON.parse(String(init.body || "{}")),
+    };
+    return createSseResponse([
+      "event: response.created\ndata: " +
+        JSON.stringify({
+          type: "response.created",
+          response: { id: "resp_agentrouter", object: "response", status: "in_progress" },
+        }),
+      "event: response.output_text.delta\ndata: " +
+        JSON.stringify({
+          type: "response.output_text.delta",
+          item_id: "msg_agentrouter",
+          output_index: 0,
+          content_index: 0,
+          delta: "OK",
+        }),
+      "event: response.completed\ndata: " +
+        JSON.stringify({
+          type: "response.completed",
+          response: {
+            id: "resp_agentrouter",
+            object: "response",
+            status: "completed",
+            model: "gpt-5.6-sol",
+            output: [],
+            usage: { input_tokens: 4, output_tokens: 1, total_tokens: 5 },
+          },
+        }),
+    ]);
+  };
+
+  const body = {
+    model: "agentrouter/gpt-5.6-sol",
+    input: "Reply with exactly OK",
+    max_output_tokens: 16,
+    stream: true,
+    store: false,
+  };
+  const result = await handleChatCore({
+    body: structuredClone(body),
+    modelInfo: { provider: "agentrouter", model: "gpt-5.6-sol", extendedContext: false },
+    credentials: { apiKey: "test-agentrouter-key", providerSpecificData: {} },
+    log: noopLog(),
+    clientRawRequest: {
+      endpoint: "/v1/responses",
+      body: structuredClone(body),
+      headers: new Headers({ accept: "text/event-stream", originator: "codex_cli_rs" }),
+    },
+    userAgent: "codex_cli_rs/0.146.0",
+  });
+
+  assert.equal(result.success, true);
+  assert.ok(captured);
+  assert.equal(captured.url, "https://agentrouter.org/v1/responses");
+  assert.equal(captured.headers.get("authorization"), "Bearer test-agentrouter-key");
+  assert.deepEqual(captured.body.input, [
+    {
+      type: "message",
+      role: "user",
+      content: [{ type: "input_text", text: body.input }],
+    },
+  ]);
+  assert.equal(captured.body.stream, true);
+  assert.equal(captured.body.store, false);
+  assert.equal("system" in captured.body, false);
+  assert.equal("thinking" in captured.body, false);
+  const text = await result.response.text();
+  assert.match(text, /response\.output_text\.delta/);
+  assert.match(text, /response\.completed/);
+  assert.match(text, /"total_tokens":5/);
+});
+
+test("AgentRouter OpenAI Chat streaming stays native without a connection protocol override", async () => {
+  let captured: { url: string; headers: Headers; body: Record<string, unknown> } | null = null;
+
+  globalThis.fetch = async (url, init = {}) => {
+    captured = {
+      url: String(url),
+      headers: new Headers(init.headers),
+      body: JSON.parse(String(init.body || "{}")),
+    };
+    return createSseResponse([
+      "data: " +
+        JSON.stringify({
+          id: "chatcmpl_agentrouter",
+          object: "chat.completion.chunk",
+          created: 1,
+          model: "gpt-5.6-sol",
+          choices: [{ index: 0, delta: { role: "assistant", content: "OK" }, finish_reason: null }],
+        }),
+      "data: " +
+        JSON.stringify({
+          id: "chatcmpl_agentrouter",
+          object: "chat.completion.chunk",
+          created: 1,
+          model: "gpt-5.6-sol",
+          choices: [{ index: 0, delta: {}, finish_reason: "stop" }],
+        }),
+      "data: " +
+        JSON.stringify({
+          id: "chatcmpl_agentrouter",
+          object: "chat.completion.chunk",
+          created: 1,
+          model: "gpt-5.6-sol",
+          choices: [],
+          usage: { prompt_tokens: 4, completion_tokens: 1, total_tokens: 5 },
+        }),
+      "data: [DONE]",
+    ]);
+  };
+
+  const body = {
+    model: "agentrouter/gpt-5.6-sol",
+    messages: [{ role: "user", content: "Reply with exactly OK" }],
+    max_completion_tokens: 16,
+    stream: true,
+  };
+  const result = await handleChatCore({
+    body: structuredClone(body),
+    modelInfo: { provider: "agentrouter", model: "gpt-5.6-sol", extendedContext: false },
+    credentials: { apiKey: "test-agentrouter-key", providerSpecificData: {} },
+    log: noopLog(),
+    clientRawRequest: {
+      endpoint: "/v1/chat/completions",
+      body: structuredClone(body),
+      headers: new Headers({ accept: "text/event-stream" }),
+    },
+    userAgent: "codex_cli_rs/0.146.0",
+  });
+
+  assert.equal(result.success, true);
+  assert.ok(captured);
+  assert.equal(captured.url, "https://agentrouter.org/v1/chat/completions");
+  assert.equal(captured.headers.get("authorization"), "Bearer test-agentrouter-key");
+  assert.equal(captured.body.stream, true);
+  assert.deepEqual(captured.body.messages, body.messages);
+  const text = await result.response.text();
+  assert.match(text, /"content":"OK"/);
+  assert.match(text, /\[DONE\]/);
+});
+
+test("AgentRouter Anthropic streaming stays native without a connection protocol override", async () => {
+  let captured: { url: string; headers: Headers; body: Record<string, unknown> } | null = null;
+
+  globalThis.fetch = async (url, init = {}) => {
+    captured = {
+      url: String(url),
+      headers: new Headers(init.headers),
+      body: JSON.parse(String(init.body || "{}")),
+    };
+    return createSseResponse([
+      "event: message_start\ndata: " +
+        JSON.stringify({
+          type: "message_start",
+          message: {
+            id: "msg_agentrouter",
+            type: "message",
+            role: "assistant",
+            model: "claude-opus-4-8",
+            usage: { input_tokens: 4, output_tokens: 0 },
+          },
+        }),
+      "event: content_block_delta\ndata: " +
+        JSON.stringify({
+          type: "content_block_delta",
+          index: 0,
+          delta: { type: "text_delta", text: "OK" },
+        }),
+      "event: message_delta\ndata: " +
+        JSON.stringify({
+          type: "message_delta",
+          delta: { stop_reason: "end_turn" },
+          usage: { output_tokens: 1 },
+        }),
+      'event: message_stop\ndata: {"type":"message_stop"}',
+    ]);
+  };
+
+  const body = {
+    model: "agentrouter/claude-opus-4-8",
+    messages: [{ role: "user", content: "Reply with exactly OK" }],
+    max_tokens: 16,
+    stream: true,
+  };
+  const result = await handleChatCore({
+    body: structuredClone(body),
+    modelInfo: { provider: "agentrouter", model: "claude-opus-4-8", extendedContext: false },
+    credentials: { apiKey: "test-agentrouter-key", providerSpecificData: {} },
+    log: noopLog(),
+    clientRawRequest: {
+      endpoint: "/v1/messages",
+      body: structuredClone(body),
+      headers: new Headers({ accept: "text/event-stream" }),
+    },
+    userAgent: "claude-cli/2.1.19",
+  });
+
+  assert.equal(result.success, true);
+  assert.ok(captured);
+  assert.equal(captured.url, "https://agentrouter.org/v1/messages?beta=true");
+  assert.equal(captured.headers.get("x-api-key"), "test-agentrouter-key");
+  assert.equal(captured.body.stream, true);
+  const text = await result.response.text();
+  assert.match(text, /content_block_delta/);
+  assert.match(text, /message_stop/);
+});

tests/unit/anthropic-cache-fingerprint.test.ts

@@ -5,6 +5,6 @@ import { CLAUDE_CODE_CLIENT_BILLING_VERSION } from "../../src/shared/constants/c
 
 describe("Anthropic billing header fingerprint (#1638)", () => {
   it("uses the immutable build revision captured from the signed CLI", () => {
-    assert.equal(CLAUDE_CODE_CLIENT_BILLING_VERSION, "2.1.219.250");
+    assert.equal(CLAUDE_CODE_CLIENT_BILLING_VERSION, "2.1.220.1f2");
   });
 });

tests/unit/cc-bridge-transforms.test.ts

@@ -52,7 +52,7 @@ test("DEFAULT_CC_BRIDGE_PIPELINE places billing header at [0] and identity at [1
     DEFAULT_CC_BRIDGE_PIPELINE
   );
   const blocks = result.body.system as any[];
-  assert.ok(blocks[0].text.startsWith("x-anthropic-billing-header: cc_version=2.1.219.250;"));
+  assert.ok(blocks[0].text.startsWith("x-anthropic-billing-header: cc_version=2.1.220.1f2;"));
   assert.equal(blocks[1].text, CLAUDE_AGENT_SDK_IDENTITY);
 });
 

tests/unit/chatcore-execution-credentials.test.ts

@@ -79,6 +79,22 @@ test("non azure/oci providers never get apiType forcing", () => {
   assert.equal(psd._omnirouteForceResponsesUpstream, undefined);
 });
 
+test("AgentRouter threads the resolved Responses protocol only into execution credentials", () => {
+  const credentials = { providerSpecificData: { apiKeyHealth: {} } };
+  const out = resolveExecutionCredentials({
+    ...base,
+    provider: "agentrouter",
+    targetFormat: RESPONSES,
+    credentials,
+  }) as Record<string, unknown>;
+
+  assert.deepEqual(out.providerSpecificData, {
+    apiKeyHealth: {},
+    targetFormat: RESPONSES,
+  });
+  assert.deepEqual(credentials.providerSpecificData, { apiKeyHealth: {} });
+});
+
 test("ccSessionId is threaded into providerSpecificData when present", () => {
   const out = resolveExecutionCredentials({
     ...base,

tests/unit/chatcore-target-format.test.ts

@@ -4,11 +4,14 @@
 // upstream target format: apiFormat==="responses" forces OpenAI Responses; otherwise the model's
 // registry target format, then the custom-model override, then the provider default. Returns both
 // `alias` (reused downstream when stripping the alias/ prefix off the upstream model) and
-// `targetFormat`. Asserted against the inline composition so the delegation stays byte-identical.
+// `targetFormat`.
 import { test } from "node:test";
 import assert from "node:assert/strict";
 import { resolveChatCoreTargetFormat } from "../../open-sse/handlers/chatCore/targetFormat.ts";
-import { PROVIDER_ID_TO_ALIAS, getModelTargetFormat } from "../../open-sse/config/providerModels.ts";
+import {
+  PROVIDER_ID_TO_ALIAS,
+  getModelTargetFormat,
+} from "../../open-sse/config/providerModels.ts";
 import { getTargetFormat } from "../../open-sse/services/provider.ts";
 import { FORMATS } from "../../open-sse/translator/formats.ts";
 
@@ -24,7 +27,9 @@ function expected(
   const targetFormat =
     apiFormat === "responses"
       ? FORMATS.OPENAI_RESPONSES
-      : modelTargetFormat || customModelTargetFormat || getTargetFormat(provider, providerSpecificData);
+      : modelTargetFormat ||
+        customModelTargetFormat ||
+        getTargetFormat(provider, providerSpecificData);
   return { alias, targetFormat };
 }
 
@@ -33,6 +38,7 @@ test("apiFormat='responses' short-circuits to OPENAI_RESPONSES (alias still reso
     provider: "openai",
     resolvedModel: "gpt-4o",
     apiFormat: "responses",
+    sourceFormat: FORMATS.OPENAI,
     customModelTargetFormat: undefined,
     providerSpecificData: undefined,
   });
@@ -45,6 +51,7 @@ test("delegates byte-identically for a normal model (no apiFormat / no custom ov
     provider: "openai",
     resolvedModel: "gpt-4o",
     apiFormat: undefined,
+    sourceFormat: FORMATS.OPENAI,
     customModelTargetFormat: undefined,
     providerSpecificData: undefined,
   });
@@ -59,6 +66,7 @@ test("customModelTargetFormat is used when the model has no registry target form
     provider: "openai",
     resolvedModel: customModel,
     apiFormat: undefined,
+    sourceFormat: FORMATS.OPENAI,
     customModelTargetFormat: "claude",
     providerSpecificData: undefined,
   });
@@ -71,17 +79,31 @@ test("falls back to getTargetFormat(provider) when neither model nor custom form
     provider: "openai",
     resolvedModel: customModel,
     apiFormat: undefined,
+    sourceFormat: FORMATS.OPENAI,
     customModelTargetFormat: undefined,
     providerSpecificData: undefined,
   });
   assert.equal(r.targetFormat, getTargetFormat("openai", undefined));
 });
 
+test("AgentRouter explicit connection protocol overrides the inferred inbound protocol", () => {
+  const r = resolveChatCoreTargetFormat({
+    provider: "agentrouter",
+    resolvedModel: "gpt-5.6-sol",
+    apiFormat: undefined,
+    sourceFormat: FORMATS.OPENAI_RESPONSES,
+    customModelTargetFormat: undefined,
+    providerSpecificData: { targetFormat: FORMATS.CLAUDE },
+  });
+  assert.equal(r.targetFormat, FORMATS.CLAUDE);
+});
+
 test("unmapped provider → alias falls back to the provider id", () => {
   const r = resolveChatCoreTargetFormat({
     provider: "some-unmapped-provider",
     resolvedModel: "x",
     apiFormat: "responses",
+    sourceFormat: FORMATS.OPENAI,
     customModelTargetFormat: undefined,
     providerSpecificData: undefined,
   });

tests/unit/executor-codex.test.ts

@@ -184,10 +184,10 @@ test("CodexExecutor.buildHeaders binds workspace ids and disables SSE accept for
   assert.equal(standardHeaders.Authorization, "Bearer codex-token");
   assert.equal(standardHeaders.Accept, "text/event-stream");
   assert.equal(standardHeaders["chatgpt-account-id"], "workspace-1");
-  assert.equal(standardHeaders.Version, "0.144.1");
+  assert.equal(standardHeaders.Version, "0.146.0");
   assert.equal(standardHeaders["Openai-Beta"], "responses=experimental");
   assert.equal(standardHeaders["X-Codex-Beta-Features"], "responses_websockets");
-  assert.equal(standardHeaders["User-Agent"], "codex-cli/0.144.1 (Windows 10.0.26200; x64)");
+  assert.equal(standardHeaders["User-Agent"], "codex-cli/0.146.0 (Windows 10.0.26200; x64)");
   assert.equal(compactHeaders.Accept, "application/json");
 });
 
@@ -213,7 +213,7 @@ test("CodexExecutor.buildHeaders honors safe env overrides for Version and User-
     },
     () => {
       const headers = executor.buildHeaders({ accessToken: "codex-token" }, true);
-      assert.equal(headers.Version, "0.144.1");
+      assert.equal(headers.Version, "0.146.0");
       assert.equal(headers["User-Agent"], "custom-codex/9.9.9");
     }
   );

tests/unit/executor-default-base.test.ts

@@ -669,9 +669,9 @@ test("DefaultExecutor.execute uses CC-compatible connection defaults to append 1
   assert.equal(calls[0].headers["anthropic-beta"].includes(CONTEXT_1M_BETA_HEADER), false);
   assert.equal(
     calls[0].headers["anthropic-beta"].includes(CLAUDE_CODE_COMPATIBLE_REDACT_THINKING_BETA),
-    false
+    true
   );
-  assert.equal(calls[1].headers["anthropic-beta"].includes(CONTEXT_1M_BETA_HEADER), true);
+  assert.equal(calls[1].headers["anthropic-beta"].includes(CONTEXT_1M_BETA_HEADER), false);
   assert.equal(
     calls[1].headers["anthropic-beta"].includes(CLAUDE_CODE_COMPATIBLE_REDACT_THINKING_BETA),
     true
@@ -1513,6 +1513,6 @@ test("DefaultExecutor.execute does not produce duplicate anthropic-version heade
   const sentBody = JSON.parse(capturedBody) as { system?: Array<{ text?: string }> };
   assert.match(
     sentBody.system?.[0]?.text ?? "",
-    /^x-anthropic-billing-header: cc_version=2\.1\.219\.250; cc_entrypoint=cli; cch=[0-9a-f]{5};$/
+    /^x-anthropic-billing-header: cc_version=2\.1\.220\.1f2; cc_entrypoint=cli; cch=[0-9a-f]{5};$/
   );
 });

tests/unit/glm-executor.test.ts

@@ -181,7 +181,7 @@ test("GlmExecutor separates OpenAI-compatible coding headers from Anthropic head
   assert.equal(anthropicHeaders["anthropic-version"], "2023-06-01");
   assert.match(anthropicHeaders["anthropic-beta"], /claude-code-20250219/);
   assert.equal(anthropicHeaders["anthropic-dangerous-direct-browser-access"], "true");
-  assert.match(anthropicHeaders["User-Agent"], /^claude-cli\/2\.1\.219 \(external, sdk-cli\)$/);
+  assert.match(anthropicHeaders["User-Agent"], /^claude-cli\/2\.1\.220 \(external, sdk-cli\)$/);
   assert.equal(anthropicHeaders["X-Stainless-Lang"], "js");
   assert.equal(anthropicHeaders["X-Stainless-Runtime"], "node");
 });

tests/unit/provider-models-route-codex.test.ts

@@ -159,11 +159,11 @@ test("provider models route merges live Codex models with the local catalog then
   assert.equal(body.discoveredCandidateCount, undefined);
   assert.deepEqual(seenRequests, [
     {
-      url: "https://chatgpt.com/backend-api/codex/models?client_version=0.144.1",
+      url: "https://chatgpt.com/backend-api/codex/models?client_version=0.146.0",
       authorization: "Bearer codex-access-token",
       workspaceId: "account-123",
       originator: "codex_cli_rs",
-      userAgent: "codex-cli/0.144.1 (Windows 10.0.26200; x64)",
+      userAgent: "codex-cli/0.146.0 (Windows 10.0.26200; x64)",
     },
     {
       url: "https://raw.githubusercontent.com/openai/codex/refs/heads/main/codex-rs/models-manager/models.json",

tests/unit/provider-request-failure-pipeline.test.ts

@@ -485,8 +485,11 @@ test("CC-compatible providerRequest log keeps request beta headers and summarize
   assert.ok(providerRequest, "providerRequest must be present on CC-compatible success");
   assert.equal(providerRequest.headers["cf-ray"], undefined);
   assert.equal(providerRequest.headers.server, undefined);
-  assert.equal(providerRequest.headers.Accept, "text/event-stream");
+  assert.equal(providerRequest.headers.Accept, "application/json");
-  assert.match(providerRequest.headers["anthropic-beta"], new RegExp(CONTEXT_1M_BETA_HEADER));
+  assert.doesNotMatch(
+    providerRequest.headers["anthropic-beta"],
+    new RegExp(CONTEXT_1M_BETA_HEADER)
+  );
   assert.match(
     providerRequest.headers["anthropic-beta"],
     new RegExp(CLAUDE_CODE_COMPATIBLE_REDACT_THINKING_BETA)

tests/unit/system-transforms.test.ts

@@ -542,7 +542,7 @@ const UI_DEFAULTS_SNAPSHOT = {
           entrypoint: "sdk-cli",
           versionFormat: "ex-machina",
           cchAlgo: "sha256-first-user",
-          buildRevision: "250",
+          buildRevision: "1f2",
         },
       ],
     },