Claude Code

Settings file

Put this in ~/.claude/settings.json, or %USERPROFILE%\.claude\settings.json on Windows.

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.overagent.cc",
    "ANTHROPIC_AUTH_TOKEN": "sk-oa_...",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "claude-sonnet-5",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "claude-opus-5",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "claude-code",
    "CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY": "1"
  }
}

Or just environment variables

export ANTHROPIC_BASE_URL=https://api.overagent.cc
export ANTHROPIC_AUTH_TOKEN=sk-oa_...
claude

Model aliases

Inside Claude Code, sonnet, opus, and haiku resolve through the ANTHROPIC_DEFAULT_* values above. Change those to change what the aliases point at — you are not restricted to Claude models, since any catalog id is valid there.

Troubleshooting

• 404 on every request — there is a /v1 on the base URL. Remove it; Claude Code appends /v1/messages itself.
• 401 — the key is being sent as ANTHROPIC_API_KEY, or it has been revoked.
• 402 — the wallet is empty. Top up and retry.
• Settings ignored — Claude Code reads the file at start-up. Restart it after editing.

Fable 5 and Opus 5 retry on a fallback model when a classifier refuses a turn. If you would rather see the refusal, see Models.