DeepSeek 3.2: Missing reasoning_content

Description

Missing `reasoning_content` field in the assistant message at message index 3. For more information, please refer to https://api-docs.deepseek.com/guides/thinking_with_tools

DeepSeek just upgraded the model, and I got an error message when using the Reasoner model.

OpenCode version

1.0.125

Steps to reproduce

Switch to DeepSeek reasoner

Screenshot and/or share link

Operating System

WSL 2

Terminal

Windows Terminal

Context from DeepSeek documentation: https://api-docs.deepseek.com/guides/reasoning_model

same question on mac

vercel/ai#10778. This is likely an upstream ai-sdk thing and there is some work started to handle this: vercel/ai#10785

In the meantime you can patch this part up to make it work:

diff --git a/packages/opencode/src/provider/transform.ts b/packages/opencode/src/provider/transform.ts
index abe269d5d..00c20bc44 100644
--- a/packages/opencode/src/provider/transform.ts
+++ b/packages/opencode/src/provider/transform.ts
@@ -4,6 +4,46 @@ import type { JSONSchema } from "zod/v4/core"
 
 export namespace ProviderTransform {
   function normalizeMessages(msgs: ModelMessage[], providerID: string, modelID: string): ModelMessage[] {
+    // DeepSeek: Handle reasoning_content for tool call continuations
+    // - With tool calls: Include reasoning_content in providerOptions so model can continue reasoning
+    // - Without tool calls: Strip reasoning (new turn doesn't need previous reasoning)
+    // See: https://api-docs.deepseek.com/guides/thinking_mode
+    if (providerID === "deepseek" || modelID.toLowerCase().includes("deepseek")) {
+      return msgs.map((msg) => {
+        if (msg.role === "assistant" && Array.isArray(msg.content)) {
+          const reasoningParts = msg.content.filter((part: any) => part.type === "reasoning")
+          const hasToolCalls = msg.content.some((part: any) => part.type === "tool-call")
+          const reasoningText = reasoningParts.map((part: any) => part.text).join("")
+
+          // Filter out reasoning parts from content
+          const filteredContent = msg.content.filter((part: any) => part.type !== "reasoning")
+
+          // If this message has tool calls and reasoning, include reasoning_content
+          // so DeepSeek can continue reasoning after tool execution
+          if (hasToolCalls && reasoningText) {
+            return {
+              ...msg,
+              content: filteredContent,
+              providerOptions: {
+                ...msg.providerOptions,
+                openaiCompatible: {
+                  ...(msg.providerOptions as any)?.openaiCompatible,
+                  reasoning_content: reasoningText,
+                },
+              },
+            }
+          }
+
+          // For final answers (no tool calls), just strip reasoning
+          return {
+            ...msg,
+            content: filteredContent,
+          }
+        }
+        return msg
+      })
+    }
+
     if (modelID.includes("claude")) {
       return msgs.map((msg) => {
         if ((msg.role === "assistant" || msg.role === "tool") && Array.isArray(msg.content)) {

@monotykamary

#4975 - Thanks @monotykamary .

There is a PR that solves the problem

Very nice, I had the same issue awesome to see it already being solved and pushed.

I merged the fix, release is going out now

If it is still an issue on 1.0.130 lmk and we can reopen

hahaha

v1.1.36 still has this bug.

this is my opencode.json

Operating System: ubuntu
Terminal: zsh

  "provider": {
    "deepseek": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "DeepSeek",
      "options": {
        "baseURL": "https://api.deepseek.com/v1",
        "apiKey": "{env:DEEPSEEK_API_KEY}"
      },
      "models": {
        "deepseek-chat": {
          "name": "DeepSeek V3",
          "limit": {
            "context": 128000,
            "output": 8192
          }
        },
        "deepseek-reasoner": {
          "name": "DeepSeek R1",
          "limit": {
            "context": 128000,
            "output": 65536
          }
        }
      }
    },

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DeepSeek 3.2: Missing `reasoning_content` #4947

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OpenCode version

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DeepSeek 3.2: Missing reasoning_content #4947

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Operating System

Terminal

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matjanos commented on Dec 1, 2025

xiaofeifeiovo commented on Dec 2, 2025

monotykamary commented on Dec 2, 2025

monotykamary commented on Dec 2, 2025

matjanos commented on Dec 2, 2025

Tim-Rambo commented on Dec 4, 2025

rekram1-node commented on Dec 4, 2025

rekram1-node commented on Dec 4, 2025

monotykamary commented on Dec 4, 2025

rekram1-node commented on Dec 4, 2025

9p15p commented on Jan 27, 2026

9p15p commented on Jan 27, 2026

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DeepSeek 3.2: Missing `reasoning_content` #4947