Anthropic API / Anthropic API

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

Fix Anthropic API 500 error with Claude Model None in Claude Code Includes evidence for Anthropic API troubleshooting demand.

Source-backed Last updated May 13, 2026 1 source Needs local verification

Category: Anthropic API
Error signature: API Error 500 — Claude Model None
Quick fix: Compare the failing environment with a known working setup, then change one configuration value at a time.
Updated: May 13, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for Anthropic API, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

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

Confirm the exact error signature matches API Error 500 — Claude Model None.
Check the Anthropic API account, local tool state, and provider configuration involved in the failing workflow.
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

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

Diagnostic flow for this page

Match API Error 500 — Claude Model None exactly before applying the quick fix.
Compare the failing environment with Anthropic API versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does API Error 500 — Claude Model None mean in Anthropic API?

API Error 500 — Claude Model None indicates the workflow described by "Anthropic API Error 500 in Claude Code — Claude Model None Regression" failed in a Anthropic API context. Start by confirming the exact signature and the component that emitted it.

What should I check first for API Error 500 — Claude Model None?

Check whether this cause matches your environment: 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.

Is the API Error 500 — Claude Model None guidance source-backed?

The "Anthropic API Error 500 in Claude Code — Claude Model None Regression" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for API Error 500 — Claude Model None?

For "Anthropic API Error 500 in Claude Code — Claude Model None Regression", avoid applying "Compare the failing environment with a known working setup, then change one configuration value at a time." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging API Error 500 — Claude Model None?

For "Anthropic API Error 500 in Claude Code — Claude Model None Regression", collect the failing Anthropic API command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.