# Debugging a relay API in Claude Code / Codex: 401 vs 404 vs 429

> Source: <https://dev.to/_e69fe8657895dd4754bbf/debugging-a-relay-api-in-claude-code-codex-401-vs-404-vs-429-33en>
> Published: 2026-10-11 01:11:54+00:00

When you point Claude Code or Codex at a third-party relay and it errors, read the status code first — it tells you exactly what's wrong:

`/v1` on `base_url`: Anthropic-compatible endpoints have `/v1/messages`); OpenAI-compatible endpoints `ANTHROPIC_AUTH_TOKEN` (Bearer), not `ANTHROPIC_API_KEY`.
Keep a couple of stations registered so a single one rate-limiting never blocks you. List with tested dates: [AI relay station list](https://jliushi.github.io/ai-relay/)

Signup links carry my referral param; strip `?aff=` if you prefer.