LiteLLM Proxy — Websearch Interception Silently Truncates Streaming Response via Claude Code /v1/messages

What this error means

websearch_interception silently truncates streaming response on /v1/messages — follow-up call always uses stream=False is a LiteLLM failure pattern reported for developers trying to fix litellm websearch_interception truncating claude code streaming responses with no error logs. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Official LiteLLM issue #27721 (2026-05-12) reports websearch_interception with Tavily via Claude Code using /v1/messages with stream=True causes final LLM output to be silently truncated mid-response with no error logs. Follow-up call always uses stream=False.

Common causes

• Developers using LiteLLM proxy with Claude Code via /v1/messages find that websearch_interception causes the final LLM output to be silently truncated mid-response with no error logs. The follow-up call defaults to stream=False, breaking Claude Code’s streaming workflow entirely.
• Official LiteLLM issue #27721 (2026-05-12) reports websearch_interception with Tavily via Claude Code using /v1/messages with stream=True causes final LLM output to be silently truncated mid-response with no error logs. Follow-up call always uses stream=False.

Quick fixes

1. Confirm the exact error signature matches websearch_interception silently truncates streaming response on /v1/messages — follow-up call always uses stream=False.
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/27721

Evidence note: Official LiteLLM issue #27721 (2026-05-12) reports websearch_interception with Tavily via Claude Code using /v1/messages with stream=True causes final LLM output to be silently truncated mid-response with no error logs. Follow-up call always uses stream=False.

Related errors

• LiteLLM streaming response truncation
• LiteLLM websearch_interception tool call failures

FAQ

What should I check first?

Start with the exact websearch_interception silently truncates streaming response on /v1/messages — follow-up call always uses stream=False 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 websearch_interception silently truncates streaming response on /v1/messages — follow-up call always uses stream=False.