fix(providers): centralize compat endpoint detection (#60399)

src/agents/openai-transport-stream.test.ts

@@ -2,6 +2,7 @@ import type { Model } from "@mariozechner/pi-ai";
 import { describe, expect, it } from "vitest";
 import {
   buildOpenAIResponsesParams,
+  buildOpenAICompletionsParams,
   buildTransportAwareSimpleStreamFn,
   isTransportAwareApiSupported,
   parseTransportChunkUsage,
@@ -304,4 +305,55 @@ describe("openai transport stream", () => {
 
     expect(params.input?.[0]).toMatchObject({ role: "developer" });
   });
+
+  it("uses system role for xAI default-route responses providers without relying on baseUrl host sniffing", () => {
+    const params = buildOpenAIResponsesParams(
+      {
+        id: "grok-4.1-fast",
+        name: "Grok 4.1 Fast",
+        api: "openai-responses",
+        provider: "xai",
+        reasoning: true,
+        input: ["text"],
+        cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+        contextWindow: 200000,
+        maxTokens: 8192,
+      } satisfies Model<"openai-responses">,
+      {
+        systemPrompt: "system",
+        messages: [],
+        tools: [],
+      } as never,
+      undefined,
+    ) as { input?: Array<{ role?: string }> };
+
+    expect(params.input?.[0]).toMatchObject({ role: "system" });
+  });
+
+  it("uses max_tokens for Chutes default-route completions providers without relying on baseUrl host sniffing", () => {
+    const params = buildOpenAICompletionsParams(
+      {
+        id: "zai-org/GLM-4.7-TEE",
+        name: "GLM 4.7 TEE",
+        api: "openai-completions",
+        provider: "chutes",
+        reasoning: true,
+        input: ["text"],
+        cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+        contextWindow: 200000,
+        maxTokens: 8192,
+      } as never,
+      {
+        systemPrompt: "system",
+        messages: [],
+        tools: [],
+      } as never,
+      {
+        maxTokens: 2048,
+      } as never,
+    );
+
+    expect(params.max_tokens).toBe(2048);
+    expect(params).not.toHaveProperty("max_completion_tokens");
+  });
 });

src/agents/openai-transport-stream.ts

@@ -1323,7 +1323,6 @@ async function processOpenAICompletionsStream(
 
 function detectCompat(model: OpenAIModeModel) {
   const provider = model.provider;
-  const baseUrl = model.baseUrl ?? "";
   const capabilities = resolveProviderRequestCapabilities({
     provider,
     api: model.api,
@@ -1336,20 +1335,26 @@ function detectCompat(model: OpenAIModeModel) {
         ? (model.compat as { supportsStore?: boolean })
         : undefined,
   });
-  const isZai = provider === "zai" || baseUrl.includes("api.z.ai");
+  const endpointClass = capabilities.endpointClass;
+  const isDefaultRoute = endpointClass === "default";
+  const isZai = endpointClass === "zai-native" || (isDefaultRoute && provider === "zai");
   const isNonStandard =
-    provider === "cerebras" ||
-    baseUrl.includes("cerebras.ai") ||
-    provider === "xai" ||
-    baseUrl.includes("api.x.ai") ||
-    baseUrl.includes("chutes.ai") ||
-    baseUrl.includes("deepseek.com") ||
+    endpointClass === "cerebras-native" ||
+    endpointClass === "chutes-native" ||
+    endpointClass === "deepseek-native" ||
+    endpointClass === "opencode-native" ||
+    endpointClass === "xai-native" ||
     isZai ||
-    provider === "opencode" ||
-    baseUrl.includes("opencode.ai");
-  const useMaxTokens = baseUrl.includes("chutes.ai");
-  const isGrok = provider === "xai" || baseUrl.includes("api.x.ai");
-  const isGroq = provider === "groq" || baseUrl.includes("groq.com");
+    (isDefaultRoute &&
+      (provider === "cerebras" ||
+        provider === "chutes" ||
+        provider === "deepseek" ||
+        provider === "opencode" ||
+        provider === "xai"));
+  const useMaxTokens =
+    endpointClass === "chutes-native" || (isDefaultRoute && provider === "chutes");
+  const isGrok = endpointClass === "xai-native" || (isDefaultRoute && provider === "xai");
+  const isGroq = endpointClass === "groq-native" || (isDefaultRoute && provider === "groq");
   const reasoningEffortMap: Record<string, string> =
     isGroq && model.id === "qwen/qwen3-32b"
       ? {
@@ -1464,7 +1469,7 @@ function convertTools(tools: NonNullable<Context["tools"]>, compat: ReturnType<t
   }));
 }
 
-function buildOpenAICompletionsParams(
+export function buildOpenAICompletionsParams(
   model: OpenAIModeModel,
   context: Context,
   options: OpenAICompletionsOptions | undefined,

src/agents/provider-attribution.test.ts

@@ -227,6 +227,37 @@ describe("provider attribution", () => {
     });
   });
 
+  it("classifies native OpenAI-compatible vendor hosts centrally", () => {
+    expect(resolveProviderEndpoint("https://api.x.ai/v1")).toMatchObject({
+      endpointClass: "xai-native",
+      hostname: "api.x.ai",
+    });
+    expect(resolveProviderEndpoint("https://api.z.ai/api/coding/paas/v4")).toMatchObject({
+      endpointClass: "zai-native",
+      hostname: "api.z.ai",
+    });
+    expect(resolveProviderEndpoint("https://api.deepseek.com")).toMatchObject({
+      endpointClass: "deepseek-native",
+      hostname: "api.deepseek.com",
+    });
+    expect(resolveProviderEndpoint("https://llm.chutes.ai/v1")).toMatchObject({
+      endpointClass: "chutes-native",
+      hostname: "llm.chutes.ai",
+    });
+    expect(resolveProviderEndpoint("https://api.groq.com/openai/v1")).toMatchObject({
+      endpointClass: "groq-native",
+      hostname: "api.groq.com",
+    });
+    expect(resolveProviderEndpoint("https://api.cerebras.ai/v1")).toMatchObject({
+      endpointClass: "cerebras-native",
+      hostname: "api.cerebras.ai",
+    });
+    expect(resolveProviderEndpoint("https://opencode.ai/api")).toMatchObject({
+      endpointClass: "opencode-native",
+      hostname: "opencode.ai",
+    });
+  });
+
   it("treats OpenRouter-hosted Responses routes as explicit proxy-like endpoints", () => {
     expect(
       resolveProviderRequestPolicy({

src/agents/provider-attribution.ts

@@ -34,14 +34,21 @@ export type ProviderRequestCapability = "llm" | "audio" | "image" | "video" | "o
 export type ProviderEndpointClass =
   | "default"
   | "anthropic-public"
+  | "cerebras-native"
+  | "chutes-native"
+  | "deepseek-native"
   | "github-copilot-native"
+  | "groq-native"
   | "mistral-public"
   | "moonshot-native"
   | "modelstudio-native"
   | "openai-public"
   | "openai-codex"
+  | "opencode-native"
   | "azure-openai"
   | "openrouter"
+  | "xai-native"
+  | "zai-native"
   | "google-generative-ai"
   | "google-vertex"
   | "local"
@@ -206,15 +213,36 @@ export function resolveProviderEndpoint(
   if (host === "api.mistral.ai") {
     return { endpointClass: "mistral-public", hostname: host };
   }
+  if (host === "api.cerebras.ai") {
+    return { endpointClass: "cerebras-native", hostname: host };
+  }
+  if (host === "llm.chutes.ai") {
+    return { endpointClass: "chutes-native", hostname: host };
+  }
+  if (host === "api.deepseek.com") {
+    return { endpointClass: "deepseek-native", hostname: host };
+  }
   if (host.endsWith(".githubcopilot.com")) {
     return { endpointClass: "github-copilot-native", hostname: host };
   }
+  if (host === "api.groq.com") {
+    return { endpointClass: "groq-native", hostname: host };
+  }
   if (host === "chatgpt.com") {
     return { endpointClass: "openai-codex", hostname: host };
   }
+  if (host === "opencode.ai" || host.endsWith(".opencode.ai")) {
+    return { endpointClass: "opencode-native", hostname: host };
+  }
   if (host === "openrouter.ai" || host.endsWith(".openrouter.ai")) {
     return { endpointClass: "openrouter", hostname: host };
   }
+  if (host === "api.x.ai") {
+    return { endpointClass: "xai-native", hostname: host };
+  }
+  if (host === "api.z.ai") {
+    return { endpointClass: "zai-native", hostname: host };
+  }
   if (host.endsWith(".openai.azure.com")) {
     return { endpointClass: "azure-openai", hostname: host };
   }
@@ -253,8 +281,16 @@ function resolveKnownProviderFamily(provider: string | undefined): string {
       return "openrouter";
     case "anthropic":
       return "anthropic";
+    case "chutes":
+      return "chutes";
+    case "deepseek":
+      return "deepseek";
     case "google":
       return "google";
+    case "xai":
+      return "xai";
+    case "zai":
+      return "zai";
     case "moonshot":
     case "kimi":
       return "moonshot";
@@ -501,14 +537,21 @@ export function resolveProviderRequestCapabilities(
   const endpointClass = policy.endpointClass;
   const isKnownNativeEndpoint =
     endpointClass === "anthropic-public" ||
+    endpointClass === "cerebras-native" ||
+    endpointClass === "chutes-native" ||
+    endpointClass === "deepseek-native" ||
     endpointClass === "github-copilot-native" ||
+    endpointClass === "groq-native" ||
     endpointClass === "mistral-public" ||
     endpointClass === "moonshot-native" ||
     endpointClass === "modelstudio-native" ||
     endpointClass === "openai-public" ||
     endpointClass === "openai-codex" ||
+    endpointClass === "opencode-native" ||
     endpointClass === "azure-openai" ||
     endpointClass === "openrouter" ||
+    endpointClass === "xai-native" ||
+    endpointClass === "zai-native" ||
     endpointClass === "google-generative-ai" ||
     endpointClass === "google-vertex";