Claude Code Multi-Turn Conversation Hangs with LiteLLM Gateway 400 Error

What this error means

API Error: 400 litellm bad request — Claude Code multi-turn conversation hangs via LiteLLM gateway is a LiteLLM failure pattern reported for developers trying to fix claude code getting stuck/hanging during multi-turn conversations when routed through litellm gateway. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

LiteLLM issue #27839 reports Claude Code hanging during multi-turn conversations when routed through LiteLLM gateway. Error: API Error: 400 with litellm bad request message. Affects Chinese developer community using proxy setups.

Common causes

• Developers using Claude Code with LiteLLM as a proxy experience multi-turn conversations that hang with a 400 bad request error. This breaks the core coding workflow and wastes paid API credits.
• LiteLLM issue #27839 reports Claude Code hanging during multi-turn conversations when routed through LiteLLM gateway. Error: API Error: 400 with litellm bad request message. Affects Chinese developer community using proxy setups.

Quick fixes

1. Confirm the exact error signature matches API Error: 400 litellm bad request — Claude Code multi-turn conversation hangs via LiteLLM gateway.
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: LiteLLM issue #27839 reports Claude Code hanging during multi-turn conversations when routed through LiteLLM gateway. Error: API Error: 400 with litellm bad request message. Affects Chinese developer community using proxy setups.

Related errors

• Claude Code conversation history limit error
• LiteLLM streaming response timeout

FAQ

What should I check first?

Start with the exact API Error: 400 litellm bad request — Claude Code multi-turn conversation hangs via LiteLLM gateway 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 API Error: 400 litellm bad request — Claude Code multi-turn conversation hangs via LiteLLM gateway.