fix(ollama): enable streaming usage for openai-compat (#66439)

* fix(ollama): enable streaming usage for openai-compat

* Update CHANGELOG.md

src/agents/openai-completions-compat.test.ts

@@ -0,0 +1,34 @@
+import { describe, expect, it } from "vitest";
+import { resolveOpenAICompletionsCompatDefaults } from "./openai-completions-compat.js";
+
+describe("resolveOpenAICompletionsCompatDefaults", () => {
+  it("enables streaming usage for local ollama OpenAI-compat endpoints", () => {
+    expect(
+      resolveOpenAICompletionsCompatDefaults({
+        provider: "ollama",
+        endpointClass: "local",
+        knownProviderFamily: "ollama",
+      }).supportsUsageInStreaming,
+    ).toBe(true);
+  });
+
+  it("keeps streaming usage enabled for custom ollama OpenAI-compat endpoints", () => {
+    expect(
+      resolveOpenAICompletionsCompatDefaults({
+        provider: "ollama",
+        endpointClass: "custom",
+        knownProviderFamily: "ollama",
+      }).supportsUsageInStreaming,
+    ).toBe(true);
+  });
+
+  it("does not broaden streaming usage for generic custom providers", () => {
+    expect(
+      resolveOpenAICompletionsCompatDefaults({
+        provider: "custom-cpa",
+        endpointClass: "custom",
+        knownProviderFamily: "custom-cpa",
+      }).supportsUsageInStreaming,
+    ).toBe(false);
+  });
+});

src/agents/openai-completions-compat.ts

@@ -33,6 +33,7 @@ export function resolveOpenAICompletionsCompatDefaults(
   input: OpenAICompletionsCompatDefaultsInput,
 ): OpenAICompletionsCompatDefaults {
   const {
+    provider,
     endpointClass,
     knownProviderFamily,
     supportsNativeStreamingUsageCompat = false,
@@ -64,7 +65,8 @@ export function resolveOpenAICompletionsCompatDefaults(
     endpointClass === "chutes-native" ||
     endpointClass === "mistral-public" ||
     knownProviderFamily === "mistral" ||
-    (isDefaultRoute && isDefaultRouteProvider(input.provider, "chutes"));
+    (isDefaultRoute && isDefaultRouteProvider(provider, "chutes"));
+  const isOllamaCompatProvider = provider === "ollama";
 
   return {
     supportsStore:
@@ -76,7 +78,8 @@ export function resolveOpenAICompletionsCompatDefaults(
       endpointClass !== "xai-native" &&
       !usesExplicitProxyLikeEndpoint,
     supportsUsageInStreaming:
-      !isNonStandard && (!usesConfiguredNonOpenAIEndpoint || supportsNativeStreamingUsageCompat),
+      isOllamaCompatProvider ||
+      (!isNonStandard && (!usesConfiguredNonOpenAIEndpoint || supportsNativeStreamingUsageCompat)),
     maxTokensField: usesMaxTokens ? "max_tokens" : "max_completion_tokens",
     thinkingFormat: isZai ? "zai" : isOpenRouterLike ? "openrouter" : "openai",
     supportsStrictMode: !isZai && !usesConfiguredNonOpenAIEndpoint,

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

@@ -1196,6 +1196,33 @@ describe("openai transport stream", () => {
     expect(params.stream_options).toMatchObject({ include_usage: true });
   });
 
+  it("enables streaming usage compat for Ollama OpenAI-compat endpoints", () => {
+    const params = buildOpenAICompletionsParams(
+      {
+        id: "qwen2.5:7b",
+        name: "Qwen 2.5 7B",
+        api: "openai-completions",
+        provider: "ollama",
+        baseUrl: "http://127.0.0.1:11434/v1",
+        reasoning: true,
+        input: ["text"],
+        cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+        contextWindow: 32768,
+        maxTokens: 8192,
+      } satisfies Model<"openai-completions">,
+      {
+        systemPrompt: "system",
+        messages: [],
+        tools: [],
+      } as never,
+      undefined,
+    ) as {
+      stream_options?: { include_usage?: boolean };
+    };
+
+    expect(params.stream_options).toMatchObject({ include_usage: true });
+  });
+
   it("disables developer-role-only compat defaults for configured custom proxy completions providers", () => {
     const params = buildOpenAICompletionsParams(
       {