Close protocol compatibility review gaps

Review feedback found narrow compatibility regressions in the web-search shim, Responses tool detection, service tier accounting, and update-center Docker candidate actions. The fix keeps synthetic search routed through the dedicated search model, preserves Responses text compatibility, distinguishes absent service_tier from filtered service_tier, and evaluates recent Docker tags per candidate.

Constraint: Review fixes must stay on dev first, then flow into the main-based release PR branch.

Rejected: Leave Responses web_search simulation on the request model | it has the same search-route selection risk as Anthropic simulation.

Confidence: high

Scope-risk: narrow

Tested: npx vitest run --root . src/server/proxy-core/responsesPreflight.test.ts src/server/proxy-core/serviceTierPolicy.test.ts src/server/routes/proxy/chat.stream.test.ts src/web/pages/settings/UpdateCenterSection.test.tsx

Tested: npm run typecheck:server

Tested: npm run typecheck:web

Tested: npm run repo:drift-check

Co-authored-by: OmX <omx@oh-my-codex.dev>

src/server/proxy-core/responsesPreflight.test.ts

@@ -1,6 +1,9 @@
 import { describe, expect, it } from 'vitest';
 
-import { validateExternalResponsesHttpRequest } from './responsesPreflight.js';
+import {
+  hasResponsesWebSearchOnlyRequest,
+  validateExternalResponsesHttpRequest,
+} from './responsesPreflight.js';
 
 describe('validateExternalResponsesHttpRequest', () => {
   it('rejects external HTTP previous_response_id and explains msg ids separately', () => {
@@ -63,3 +66,21 @@ describe('validateExternalResponsesHttpRequest', () => {
   });
 });
 
+describe('hasResponsesWebSearchOnlyRequest', () => {
+  it('recognizes the current web_search_preview tool alias', () => {
+    expect(hasResponsesWebSearchOnlyRequest({
+      model: 'gpt-5',
+      tools: [{ type: 'web_search_preview_2025_03_11' }],
+      input: 'metapi protocol compatibility',
+    })).toBe(true);
+
+    expect(hasResponsesWebSearchOnlyRequest({
+      model: 'gpt-5',
+      tools: [
+        { type: 'web_search_preview_2025_03_11' },
+        { type: 'function', name: 'lookup' },
+      ],
+      input: 'metapi protocol compatibility',
+    })).toBe(false);
+  });
+});

src/server/proxy-core/responsesPreflight.ts

@@ -120,6 +120,7 @@ function isWebSearchToolRecord(tool: Record<string, unknown>): boolean {
   const name = asTrimmedString(tool.name).toLowerCase();
   return type === 'web_search'
     || type === 'web_search_preview'
+    || type === 'web_search_preview_2025_03_11'
     || type === 'web_search_20250305'
     || type === 'google_search'
     || name === 'web_search'

src/server/proxy-core/serviceTierPolicy.test.ts

@@ -3,7 +3,15 @@ import { describe, expect, it } from 'vitest';
 import { applyOpenAiServiceTierPolicy } from './serviceTierPolicy.js';
 
 describe('applyOpenAiServiceTierPolicy', () => {
-  it('normalizes fast to priority and drops unknown or non-string tiers', () => {
+  it('normalizes fast to priority, leaves absent tiers alone, and drops unknown or non-string tiers', () => {
+    expect(applyOpenAiServiceTierPolicy({
+      body: { model: 'gpt-5' },
+    })).toMatchObject({
+      ok: true,
+      body: { model: 'gpt-5' },
+      action: 'pass',
+    });
+
     expect(applyOpenAiServiceTierPolicy({
       body: { model: 'gpt-5', service_tier: ' fast ' },
     })).toMatchObject({
@@ -73,4 +81,3 @@ describe('applyOpenAiServiceTierPolicy', () => {
     }
   });
 });
-

src/server/proxy-core/serviceTierPolicy.ts

@@ -126,6 +126,7 @@ export function applyOpenAiServiceTierPolicy(input: {
   context?: ServiceTierRuleContext;
   rules?: unknown;
 }): ServiceTierPolicyResult {
+  const hasRequestedServiceTier = Object.prototype.hasOwnProperty.call(input.body, 'service_tier');
   const rawTier = input.body.service_tier;
   const serviceTier = normalizeServiceTier(rawTier);
   const next = { ...input.body };
@@ -135,7 +136,7 @@ export function applyOpenAiServiceTierPolicy(input: {
     return {
       ok: true,
       body: next,
-      action: 'filter',
+      action: hasRequestedServiceTier ? 'filter' : 'pass',
     };
   }
 
@@ -160,4 +161,3 @@ export function applyOpenAiServiceTierPolicy(input: {
     action: 'pass',
   };
 }
-

src/server/proxy-core/webSearchSimulation.ts

@@ -14,6 +14,8 @@ function asTrimmedString(value: unknown): string {
   return typeof value === 'string' ? value.trim() : '';
 }
 
+const SEARCH_SIMULATION_MODEL = '__search';
+
 function findSearchTool(body: Record<string, unknown>): Record<string, unknown> | null {
   const tools = Array.isArray(body.tools) ? body.tools : [];
   for (const tool of tools) {
@@ -23,6 +25,7 @@ function findSearchTool(body: Record<string, unknown>): Record<string, unknown>
     if (
       type === 'web_search'
       || type === 'web_search_preview'
+      || type === 'web_search_preview_2025_03_11'
       || type === 'web_search_20250305'
       || type === 'google_search'
       || name === 'web_search'
@@ -129,6 +132,7 @@ function buildSyntheticResponsesPayload(input: {
   const responseId = `resp_web_search_${randomUUID()}`;
   const searchCallId = `ws_${randomUUID()}`;
   const results = normalizeSearchResults(input.searchPayload);
+  const outputText = results.length > 0 ? JSON.stringify(results) : '[]';
 
   return {
     id: responseId,
@@ -136,6 +140,7 @@ function buildSyntheticResponsesPayload(input: {
     created_at: createdAt,
     model: asTrimmedString(input.body.model) || 'unknown',
     status: 'completed',
+    output_text: outputText,
     output: [
       {
         id: searchCallId,
@@ -153,9 +158,7 @@ function buildSyntheticResponsesPayload(input: {
         status: 'completed',
         content: [{
           type: 'output_text',
-          text: results.length > 0
-            ? JSON.stringify(results)
-            : '[]',
+          text: outputText,
         }],
       },
     ],
@@ -193,7 +196,7 @@ async function sendAnthropicSearchSimulation(input: {
     app: input.app,
     request: input.request,
     query,
-    model: asTrimmedString(input.body.model) || asTrimmedString(input.openAiBody.model) || '__search',
+    model: SEARCH_SIMULATION_MODEL,
     maxResults: toSearchMaxResults(tool),
   });
   if (search.statusCode < 200 || search.statusCode >= 300) {
@@ -252,7 +255,7 @@ async function sendResponsesSearchSimulation(input: {
     app: input.app,
     request: input.request,
     query,
-    model: asTrimmedString(input.body.model) || '__search',
+    model: SEARCH_SIMULATION_MODEL,
     maxResults: toSearchMaxResults(tool),
   });
   if (search.statusCode < 200 || search.statusCode >= 300) {

src/server/routes/proxy/chat.stream.test.ts

@@ -4749,6 +4749,7 @@ describe('chat proxy stream behavior', () => {
 
     expect(response.statusCode, response.body).toBe(200);
     expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(selectChannelMock).toHaveBeenCalledWith('__search', expect.anything());
     const [targetUrl, options] = fetchMock.mock.calls[0] as [string, any];
     expect(targetUrl).toBe('https://upstream.example.com/v1/search');
     expect(JSON.parse(options.body)).toMatchObject({
@@ -4816,6 +4817,7 @@ describe('chat proxy stream behavior', () => {
 
     expect(response.statusCode, response.body).toBe(200);
     expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(selectChannelMock).toHaveBeenCalledWith('__search', expect.anything());
     const [targetUrl, options] = fetchMock.mock.calls[0] as [string, any];
     expect(targetUrl).toBe('https://upstream.example.com/v1/search');
     expect(JSON.parse(options.body)).toMatchObject({
@@ -4825,6 +4827,7 @@ describe('chat proxy stream behavior', () => {
 
     const body = response.json();
     expect(body.object).toBe('response');
+    expect(body.output_text).toContain('Metapi Responses');
     expect(body.output?.[0]).toMatchObject({
       type: 'web_search_call',
       status: 'completed',

src/server/services/updateCenterStatusService.ts

@@ -5,7 +5,6 @@ import {
   fetchDockerHubTagCandidates,
   fetchLatestStableGitHubRelease,
   getCurrentRuntimeVersion,
-  type DockerHubTagCandidates,
   type UpdateCenterVersionCandidate,
 } from './updateCenterVersionService.js';
 import {
@@ -164,8 +163,8 @@ export async function buildUpdateCenterStatus(): Promise<UpdateCenterStatusResul
     loadUpdateCenterRuntimeState(),
   ]);
 
-  const githubRelease = githubLookup.value as UpdateCenterVersionCandidate | null;
-  const dockerHubCandidates = dockerLookup.value as DockerHubTagCandidates | null;
+  const githubRelease = githubLookup.value;
+  const dockerHubCandidates = dockerLookup.value;
   const dockerHubTag = dockerHubCandidates?.primary || null;
   const dockerHubRecentTags = dockerHubCandidates?.recentNonStable || [];
   const helper = (helperLookup.value as UpdateCenterHelperStatus | null) || buildUnavailableHelperStatus(helperLookup.error);