Set up Anthropic

Connect Anthropic

• Open Settings → AI Providers and select Anthropic
• Paste the Anthropic API key into the API key field
• Keep the built-in models endpoint /v1/models unless Anthropic documents a different path for your environment
• Choose Sync now to fetch models, enable Anthropic, and make it the active provider
• Choose a suitable Claude model from the Agent model picker

Connection used by Kition

The Anthropic preset uses the Messages wire. Do not change a custom endpoint to responses merely because another service describes itself as OpenAI-compatible; the selected wire must match the endpoint implementation.

Base URL:       https://api.anthropic.com
Models endpoint: /v1/models
Wire API:       anthropic_messages
Authentication: x-api-key

Choose current models, not copied IDs

Model names, aliases, access rules, and pricing change independently of Kition. Sync the catalog and choose an identifier returned for the connected Anthropic workspace instead of relying on a fixed list in documentation.

If a model is listed but rejects a task, check its current Messages API and tool support in Anthropic’s documentation and verify that the workspace has access.

Credential storage in 0.1.41

The key is stored outside the workspace in Kition application data. The local secret file is plaintext in this release and is not stored in the operating-system keychain.

Troubleshoot safely

• 401 — re-enter the key and check for accidental whitespace or revocation
• 403 — verify workspace permissions, model access, and regional restrictions
• 404 during sync — restore the built-in Base URL and /v1/models path
• 429 — check the current Anthropic usage tier and rate-limit response
• A tool or long request is rejected — check the selected model’s current capability and input limits in Anthropic’s official documentation