From f699ea55a80b0df298247c53d52b514445d1f36d Mon Sep 17 00:00:00 2001
From: CreatorGhost <cybercreed010@gmail.com>
Date: Sun, 12 Jul 2026 02:05:30 +0530
Subject: [PATCH] fix(llm): accept Ollama reasoning field in OpenAI Chat deltas

Ported from upstream anomalyco/opencode#36068.
---
 packages/llm/src/protocols/openai-chat.ts     | 15 ++++++++---
 .../llm/test/provider/openai-chat.test.ts     | 26 +++++++++++++++++++
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/packages/llm/src/protocols/openai-chat.ts b/packages/llm/src/protocols/openai-chat.ts
index 9ac85b07b139..514671e83000 100644
--- a/packages/llm/src/protocols/openai-chat.ts
+++ b/packages/llm/src/protocols/openai-chat.ts
@@ -75,6 +75,7 @@ const OpenAIChatMessage = Schema.Union([
     content: Schema.NullOr(Schema.String),
     tool_calls: optionalArray(OpenAIChatAssistantToolCall),
     reasoning_content: Schema.optional(Schema.String),
+    reasoning: Schema.optional(Schema.String),
   }),
   Schema.Struct({ role: Schema.Literal("tool"), tool_call_id: Schema.String, content: Schema.String }),
 ]).pipe(Schema.toTaggedUnion("role"))
@@ -145,6 +146,7 @@ type OpenAIChatToolCallDelta = Schema.Schema.Type<typeof OpenAIChatToolCallDelta
 const OpenAIChatDelta = Schema.Struct({
   content: optionalNull(Schema.String),
   reasoning_content: optionalNull(Schema.String),
+  reasoning: optionalNull(Schema.String),
   tool_calls: optionalNull(Schema.Array(OpenAIChatToolCallDelta)),
 })
 
@@ -208,7 +210,13 @@ const lowerMedia = Effect.fn("OpenAIChat.lowerMedia")(function* (part: MediaPart
 })
 
 const openAICompatibleReasoningContent = (native: unknown) =>
-  isRecord(native) && typeof native.reasoning_content === "string" ? native.reasoning_content : undefined
+  isRecord(native)
+    ? typeof native.reasoning_content === "string"
+      ? native.reasoning_content
+      : typeof native.reasoning === "string"
+        ? native.reasoning
+        : undefined
+    : undefined
 
 const lowerUserMessage = Effect.fn("OpenAIChat.lowerUserMessage")(function* (message: OpenAIChatRequestMessage) {
   const content: Array<Schema.Schema.Type<typeof OpenAIChatUserContent>> = []
@@ -416,8 +424,9 @@ const step = (state: ParserState, event: OpenAIChatEvent) =>
 
     let lifecycle = state.lifecycle
 
-    if (delta?.reasoning_content)
-      lifecycle = Lifecycle.reasoningDelta(lifecycle, events, "reasoning-0", delta.reasoning_content)
+    const reasoningText = delta ? openAICompatibleReasoningContent(delta) : undefined
+    if (reasoningText)
+      lifecycle = Lifecycle.reasoningDelta(lifecycle, events, "reasoning-0", reasoningText)
 
     if (delta?.content) {
       lifecycle = Lifecycle.reasoningEnd(lifecycle, events, "reasoning-0")
diff --git a/packages/llm/test/provider/openai-chat.test.ts b/packages/llm/test/provider/openai-chat.test.ts
index b736dc9dd33c..bf16adb08f9a 100644
--- a/packages/llm/test/provider/openai-chat.test.ts
+++ b/packages/llm/test/provider/openai-chat.test.ts
@@ -552,6 +552,32 @@ describe("OpenAI Chat route", () => {
     }),
   )
 
+  it.effect("parses Ollama reasoning field deltas (reasoning alias for reasoning_content)", () =>
+    Effect.gen(function* () {
+      const body = sseEvents(
+        { choices: [{ delta: { reasoning: "thinking" } }] },
+        { choices: [{ delta: { content: "Hello" } }] },
+        { choices: [{ delta: {}, finish_reason: "stop" }] },
+      )
+
+      const response = yield* LLMClient.generate(request).pipe(Effect.provide(fixedResponse(body)))
+
+      expect(response.reasoning).toBe("thinking")
+      expect(response.text).toBe("Hello")
+      expect(response.events).toMatchObject([
+        { type: "step-start", index: 0 },
+        { type: "reasoning-start", id: "reasoning-0" },
+        { type: "reasoning-delta", id: "reasoning-0", text: "thinking" },
+        { type: "reasoning-end", id: "reasoning-0" },
+        { type: "text-start", id: "text-0" },
+        { type: "text-delta", id: "text-0", text: "Hello" },
+        { type: "text-end", id: "text-0" },
+        { type: "step-finish", index: 0, reason: "stop" },
+        { type: "finish", reason: "stop" },
+      ])
+    }),
+  )
+
   it.effect("assembles streamed tool call input", () =>
     Effect.gen(function* () {
       const body = sseEvents(