Bifrost Proxy Breaks Tool-Using Requests When Routing OpenAI Format to Anthropic Models

What this error means

Bifrost v1.5.2: OpenAI→Anthropic tool-payload translation breaks all tool-using requests routed to Anthropic — GatewayClientRequestError: FailoverError is a Bifrost failure pattern reported for developers trying to fix bifrost proxy failing to translate openai tool specs to anthropic format. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

v1.5.2 regression. OpenAI-format tool specs routed to Anthropic produce schema validation error 400. Same payload works for all other providers. Breaks every tool-using client through Bifrost.

Common causes

• Bifrost v1.5.2 breaks all tool-using clients (OpenClaw, OpenAI SDK) when routing to Anthropic models. The OpenAI→Anthropic tool-payload translation produces invalid schema. Same request works fine to OpenAI, Gemini, xAI, Ollama.
• v1.5.2 regression. OpenAI-format tool specs routed to Anthropic produce schema validation error 400. Same payload works for all other providers. Breaks every tool-using client through Bifrost.

Quick fixes

1. Confirm the exact error signature matches Bifrost v1.5.2: OpenAI→Anthropic tool-payload translation breaks all tool-using requests routed to Anthropic — GatewayClientRequestError: FailoverError.
2. Check the Bifrost 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/maximhq/bifrost/issues/3511

Evidence note: v1.5.2 regression. OpenAI-format tool specs routed to Anthropic produce schema validation error 400. Same payload works for all other providers. Breaks every tool-using client through Bifrost.

Related errors

• Bifrost Anthropic model routing failure
• OpenAI SDK tool call format error
• LiteLLM Anthropic tool translation

FAQ

What should I check first?

Start with the exact Bifrost v1.5.2: OpenAI→Anthropic tool-payload translation breaks all tool-using requests routed to Anthropic — GatewayClientRequestError: FailoverError text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Bifrost 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 Bifrost v1.5.2: OpenAI→Anthropic tool-payload translation breaks all tool-using requests routed to Anthropic — GatewayClientRequestError: FailoverError.