Troubleshooting gpt-oss and vLLM Errors

When to Use This Skill

Invoke this skill when you encounter:

• openai_harmony.HarmonyError messages in any context
• gpt-oss tool calling failures or unexpected behavior
• Token parsing errors with vLLM serving gpt-oss models
• Users asking about gpt-oss compatibility with frameworks like llama-stack

Critical First Step: Identify Error Source

IMPORTANT: openai_harmony.HarmonyError messages originate from the vLLM server, NOT from client applications (like llama-stack, LangChain, etc.).

Error Source Identification