Anthropic API Error 500 in Claude Code — Claude Model None Regression

What this error means

API Error 500 — Claude Model None is a Anthropic API failure pattern reported for developers trying to fix anthropic api 500 error with claude model none in claude code. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Official GitHub issue from anthropics/claude-code repo. Bug report: API Error 500 on every prompt. Confirmed regression (worked in previous version). Claude Code Version 1.0.100. Platform: Anthropic API. macOS Terminal.app.

Common causes

• Every prompt in Claude Code triggers a 500 API error showing ‘Claude Model None’. This is a confirmed regression that was working in a previous version. Developers using the paid Claude Code service cannot complete any tasks. High commercial value because it blocks all usage of a paid product.
• Official GitHub issue from anthropics/claude-code repo. Bug report: API Error 500 on every prompt. Confirmed regression (worked in previous version). Claude Code Version 1.0.100. Platform: Anthropic API. macOS Terminal.app.

Quick fixes

1. Confirm the exact error signature matches API Error 500 — Claude Model None.
2. Check the Anthropic API 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/anthropics/claude-code/issues/57252

Evidence note: Official GitHub issue from anthropics/claude-code repo. Bug report: API Error 500 on every prompt. Confirmed regression (worked in previous version). Claude Code Version 1.0.100. Platform: Anthropic API. macOS Terminal.app.

Related errors

• Anthropic API 500 Internal Server Error
• Claude Code model not found after update
• Claude Code all prompts failing 500 error

FAQ

What should I check first?

Start with the exact API Error 500 — Claude Model None text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Anthropic API 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 500 — Claude Model None.