Deepseek-chat:options:thinking:type:enabled thinking tools bug #9397

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1. ai-llt

   added

   bugSomething isn't workingSomething isn't working

   on Jan 19, 2026
2. github-actions

   assigned

   thdxr

   on Jan 19, 2026
3. github-actions

   added

   windows

   on Jan 19, 2026
4. github-actions commented on Jan 19, 2026

   

   github-actionsBot

   on Jan 19, 2026 – with GitHub Actions

   Contributor

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   This issue might be a duplicate of existing issues. Please check:

   • The problem with deepseek-reasoner in OpenCode #8934: The problem with deepseek-reasoner in OpenCode
   • Deepseek missing "reasoning_content" field ; deepseek_reasoner model erroring out #5027: Deepseek missing "reasoning_content" field ; deepseek_reasoner model erroring out
   • DeepSeek 3.2: Missing reasoning_content #4947: DeepSeek 3.2: Missing reasoning_content
   • DeepSeek V3.2 : reasoning_content not cleared from message history on new turns, causing excess token usage and violating API spec #5577: DeepSeek V3.2 : reasoning_content not cleared from message history on new turns, causing excess token usage and violating API spec

   Feel free to ignore if none of these address your specific case.
5. tongsh6 commented on Mar 10, 2026

   

   tongsh6

   on Mar 10, 2026

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   I can reproduce the same class of bug in a slightly different setup: a custom local subagent using deepseek/deepseek-reasoner with tools enabled.

   Local agent file:

   ~/.config/opencode/agents/architect.md

   ---
   description: Read-only architecture review agent
   mode: subagent
   model: deepseek/deepseek-reasoner
   temperature: 0.1
   steps: 16
   tools:
     write: false
     edit: false
     bash: true
   ---

   Observed error:

   Missing reasoning_content field in the assistant message at message index 32.
   For more information, please refer to https://api-docs.deepseek.com/guides/thinking_mode#tool-calls
   

   So this does not seem limited to deepseek-chat with thinking.type=enabled; it also appears in custom subagent flows with deepseek-reasoner when tool calls are involved.

   Related issue with more detail: #8934.
6. thdxr

   removed

   bugSomething isn't workingSomething isn't working

   windows

   on May 3, 2026
7. github-actions commented on Jul 6, 2026

   

   github-actionsBot

   on Jul 6, 2026 – with GitHub Actions

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   To stay organized issues are automatically closed after 60 days of no activity. If the issue is still relevant please open a new one.
8. github-actions

   closed this as not plannedon Jul 6, 2026