Claude Code Multi-turn Conversation Hangs via LiteLLM Gateway with 178 Validation Errors

What this error means

litellm.BadRequestError: OpenAIException - 178 validation errors: Input should be a valid string is a LiteLLM failure pattern reported for developers trying to fix claude code hanging on multi-turn conversations when using litellm as api gateway with 178 validation errors. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Open issue on BerriAI/litellm. Chinese-language report of Claude Code calls to LiteLLM gateway hanging on multi-turn conversations. Error: 178 validation errors with ‘Input should be a valid string’ — schema format mismatch.

Common causes

• Claude Code users routing through LiteLLM gateway experience complete conversation hangs. The 178 validation errors suggest deep schema mismatch between Claude Code’s expected format and LiteLLM’s proxy translation.
• Open issue on BerriAI/litellm. Chinese-language report of Claude Code calls to LiteLLM gateway hanging on multi-turn conversations. Error: 178 validation errors with ‘Input should be a valid string’ — schema format mismatch.

Quick fixes

1. Confirm the exact error signature matches litellm.BadRequestError: OpenAIException - 178 validation errors: Input should be a valid string.
2. Check the LiteLLM account, local tool state, and provider configuration involved in the failing workflow.
3. Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

• Verify the command, editor, extension, or API client that produced the error.
• Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
• Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

1. Capture the exact error message and the command, editor action, or request that triggered it.
2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
3. Review the source evidence below and compare it with your environment.
4. Apply one change at a time and rerun the smallest failing action.
5. Keep the working fix documented for the team or deployment environment.

How to prevent it

• Keep provider/tool configuration documented.
• Record non-secret diagnostics such as tool version, provider name, model name, and command path.
• Add a lightweight check before CI or production workflows depend on the tool.

Sources checked

• https://github.com/BerriAI/litellm/issues/27839

Evidence note: Open issue on BerriAI/litellm. Chinese-language report of Claude Code calls to LiteLLM gateway hanging on multi-turn conversations. Error: 178 validation errors with ‘Input should be a valid string’ — schema format mismatch.

Related errors

• LiteLLM Claude Code compatibility
• LiteLLM validation error multi-turn
• Claude Code gateway proxy error

FAQ

What should I check first?

Start with the exact litellm.BadRequestError: OpenAIException - 178 validation errors: Input should be a valid string text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed LiteLLM workflow until the root cause is understood.

Is this guaranteed to have one fix?

No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.

How do I know the fix worked?

Rerun the same command, editor action, or request. The fix is working when that action completes without litellm.BadRequestError: OpenAIException - 178 validation errors: Input should be a valid string.