fix(xai): stop stripping web_search fields xAI accepts

src/adapters/xai-web-search.ts

@@ -60,10 +60,15 @@ function normalizeToolGroup(tools: unknown[]): ToolGroupRewrite {
       : undefined;
     const enableImageSearch = searchContentTypes?.includes("image") === true;
     const next: Record<string, unknown> = { ...tool, type: CODEX_WEB_SEARCH_TOOL };
+    // Only the two fields xAI actually refuses are removed. Probed 2026-08-22, one field per
+    // request, against BOTH xAI destinations (api.x.ai and cli-chat-proxy.grok.com): they behave
+    // identically — `external_web_access` 400s on every value including `true`, and
+    // `search_context_size` 400s, while `user_location`, `search_content_types`, `filters` and
+    // `enable_image_search` are all accepted. Deleting the accepted ones was a silent capability
+    // loss, and it contradicted the sibling layer, whose own probe note already records
+    // user_location/filters as accepted (tests/responses-routed-web-search-fields.test.ts).
     delete next.external_web_access;
     delete next.search_context_size;
-    delete next.search_content_types;
-    delete next.user_location;
     if (enableImageSearch && !Object.hasOwn(next, "enable_image_search")) {
       next.enable_image_search = true;
     }

tests/responses-routed-web-search-fields.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, test } from "bun:test";
 import { createResponsesPassthroughAdapter as createResponsesPassthroughAdapterProduction, stripOpenAiOnlyWebSearchFields } from "../src/adapters/openai-responses";
 import { enrichProviderFromRegistry, providerConfigSeed } from "../src/providers/derive";
 import { getProviderRegistryEntry } from "../src/providers/registry";
+import { resolveProviderTransport } from "../src/providers/xai-transport";
 import { routedProviderConfig } from "../src/router";
 import type { OcxProviderConfig } from "../src/types";
 import { withTestTranslatorBudget } from "./helpers/translator-budget";
@@ -23,6 +24,8 @@ function buildWebSearchBody(provider: OcxProviderConfig): Record<string, unknown
         external_web_access: true,
         search_context_size: "medium",
         user_location: { type: "approximate" },
+        search_content_types: ["text"],
+        filters: { allowed_domains: ["x.ai"] },
       }],
     },
   }, { headers: new Headers() });
@@ -92,17 +95,24 @@ describe("Responses buildRequest web_search capability", () => {
       external_web_access: true,
       search_context_size: "medium",
       user_location: { type: "approximate" },
+      search_content_types: ["text"],
+      filters: { allowed_domains: ["x.ai"] },
     }]);
   });
 
-  test("registry xAI traffic normalizes Codex search fields for its public Responses API", () => {
+  test("registry xAI traffic keeps accepted fields on the public api.x.ai Responses API", () => {
     const entry = getProviderRegistryEntry("xai");
     if (!entry) throw new Error("xAI registry entry missing");
     const provider = { ...providerConfigSeed(entry), adapter: "openai-responses" };
     enrichProviderFromRegistry("xai", provider);
 
     const body = buildWebSearchBody(provider);
-    expect(body.tools).toEqual([{ type: "web_search" }]);
+    expect(body.tools).toEqual([{
+      type: "web_search",
+      user_location: { type: "approximate" },
+      search_content_types: ["text"],
+      filters: { allowed_domains: ["x.ai"] },
+    }]);
   });
 
   test("non-xAI classified gateways use generic field stripping, not xAI cached-search policy", () => {
@@ -184,16 +194,47 @@ describe("routedProviderConfig web_search capability backfill", () => {
     expect(routed.supportsOpenAiWebSearchToolFields).toBe(false);
   });
 
-  test("the routed row actually normalizes the search tool at the adapter", () => {
+  test("the registry-classified OAuth row strips only fatal fields at the CLI adapter", () => {
     const routed = routedProviderConfig("xai", {
       adapter: "openai-chat",
       baseUrl: "https://api.x.ai/v1",
       authMode: "oauth",
       modelAdapters: { "grok-4.6": "openai-responses" },
     });
+    const transport = resolveProviderTransport("xai", routed);
+
+    expect(transport.baseUrl).toBe("https://cli-chat-proxy.grok.com/v1");
+    const body = buildWebSearchBody({ ...transport, adapter: "openai-responses" });
+    expect(body.tools).toEqual([{
+      type: "web_search",
+      user_location: { type: "approximate" },
+      search_content_types: ["text"],
+      filters: { allowed_domains: ["x.ai"] },
+    }]);
+  });
 
-    const body = buildWebSearchBody({ ...routed, adapter: "openai-responses" });
-    expect(body.tools).toEqual([{ type: "web_search" }]);
+  test("an equivalent unclassified OAuth row retains fatal fields at the CLI adapter", () => {
+    const routed = routedProviderConfig("xai", {
+      adapter: "openai-chat",
+      baseUrl: "https://api.x.ai/v1",
+      authMode: "oauth",
+      modelAdapters: { "grok-4.6": "openai-responses" },
+    });
+    const unclassified = { ...routed };
+    delete unclassified.supportsOpenAiWebSearchToolFields;
+    const transport = resolveProviderTransport("xai", unclassified);
+
+    expect(transport.baseUrl).toBe("https://cli-chat-proxy.grok.com/v1");
+    expect(transport.supportsOpenAiWebSearchToolFields).toBeUndefined();
+    const body = buildWebSearchBody({ ...transport, adapter: "openai-responses" });
+    expect(body.tools).toEqual([{
+      type: "web_search",
+      external_web_access: true,
+      search_context_size: "medium",
+      user_location: { type: "approximate" },
+      search_content_types: ["text"],
+      filters: { allowed_domains: ["x.ai"] },
+    }]);
   });
 
   test("an explicit saved value still overrides the registry default", () => {

tests/xai-web-search-compat.test.ts

@@ -24,7 +24,12 @@ function buildBody(rawBody: Record<string, unknown>): Record<string, unknown> {
 }
 
 describe("xAI Responses web-search compatibility", () => {
-  test("lowers Codex live-search fields to xAI's documented tool schema", () => {
+  // Probed 2026-08-22, one field per request, against BOTH xAI destinations (api.x.ai and
+  // cli-chat-proxy.grok.com), which behave identically: external_web_access 400s on every value
+  // including `true`, search_context_size 400s, and user_location / search_content_types /
+  // filters / enable_image_search are all accepted. Only the two refused fields are removed;
+  // deleting the accepted ones was a silent capability loss.
+  test("removes only the fields xAI refuses and keeps the accepted ones", () => {
     const body = buildBody({
       model: "grok-4.6",
       input: "latest xAI news",
@@ -42,13 +47,13 @@ describe("xAI Responses web-search compatibility", () => {
     expect(body.tools).toEqual([{
       type: "web_search",
       filters: { allowed_domains: ["x.ai"] },
+      user_location: { type: "approximate", country: "KR" },
+      search_content_types: ["text", "image"],
       enable_image_search: true,
     }]);
     expect(body.tool_choice).toEqual({ type: "web_search" });
     expect(JSON.stringify(body)).not.toContain("external_web_access");
     expect(JSON.stringify(body)).not.toContain("search_context_size");
-    expect(JSON.stringify(body)).not.toContain("search_content_types");
-    expect(JSON.stringify(body)).not.toContain("user_location");
   });
 
   test("omits cached-only search instead of silently widening it to xAI live search", () => {