Kimi K2 Thinking tool calling problems - missing arguments. #9878

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1. benys

   added

   bugSomething isn't workingSomething isn't working

   on Jan 21, 2026
2. github-actions

   assigned

   fwang

   on Jan 21, 2026
3. github-actions

   added

   nix

   zenRelates to ZenRelates to Zen

   on Jan 21, 2026
4. github-actions commented on Jan 21, 2026

   

   github-actionsbot

   on Jan 21, 2026 – with GitHub Actions

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

   • Tools with array/object parameters fail when LLM sends stringified JSON #7512: Tools with array/object parameters fail when LLM sends stringified JSON - similar tool argument validation issues
   • qwen3-coder fails to call edit tool #6918: qwen3-coder fails to call edit tool - similar model/tool parameter issues
   • Claude models fail on MCP tools with no required parameters (undefined vs {}) #9020: Claude models fail on MCP tools with no required parameters (undefined vs {}) - related to empty/invalid arguments
   • 🐛 Bug Report: MCP Tool JSON Parsing Errors on OpenCode (GLM-4.7) #8102: MCP Tool JSON Parsing Errors on OpenCode (GLM-4.7) - similar invalid JSON for tool arguments
   • Weird error with toolcalling on local model #6649: Weird error with toolcalling on local model - similar tool calling validation issues
   • ConfigInvalidError on Windows due to unrecognized keys in opencode.json #7483: Tools with typed parameters fail when LLM sends stringified parameters

   The common thread is that certain models (especially newer/thinking models like Kimi K2) pass invalid or empty arguments to tools, causing validation failures. This appears to be a systematic issue with how some models format tool call arguments.

   Feel free to ignore if none of these address your specific case.
5. benys

   added a commit that references this issue on Jan 24, 2026

   fix: parse Kimi K2 Thinking tool calls with special tokens

   ...

   This issue will close once commit f3b4982 is merged into the 'dev' branch.

   f3b4982
6. benys commented on Jan 24, 2026

   

   benys

   on Jan 24, 2026

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   Maybe newest opencode fixit ? i close
7. benys

   closed this as completedon Jan 24, 2026
8. Rukasufall commented on Jan 24, 2026

   

   Rukasufall

   on Jan 24, 2026

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   Using opencode and Ollama, I’m having the same issue.
   I tested the Qwen3-coder:30b and GLM 4.7 Flash:q4_k_m models. They can create a file with code (usually small snippets), but they can’t call it back to edit it.

   Glm 4.7 flash:

   ~ Reading file...
   Error: The read tool was called with invalid arguments: [
   {
   "expected": "string",
   "code": "invalid_type",
   "path": [
   "filePath"
   ],
   "message": "Invalid input: expected string, received undefined"
   }
   ].
   Please rewrite the input so it satisfies the expected schema.

   Qwen3-coder:30b:

   ~ Reading file...
   Error: The read tool was called with invalid arguments: [
   {
   "expected": "string",
   "code": "invalid_type",
   "path": [
   "filePath"
   ],
   "message": "Invalid input: expected string, received undefined"
   }
   ].
   Please rewrite the input so it satisfies the expected schema.
9. Nickersoft commented on Feb 26, 2026

   

   Nickersoft

   on Feb 26, 2026

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   Can confirm this is still happening with KIMI K2 on the latest of OpenCode (via OpenCode Zen) cc @benys. Might be worth reopening?