Bring your own Anthropic key

If you already have Anthropic credits or a commitment, connect your own API key and agent model calls bill your Anthropic account instead of your Ellipsis bill. This is an account-level setting: it applies to every agent and requires no YAML changes.

Connect a key

1. Open Models in the dashboard and find Bring your own Anthropic API key.
2. Click Add key, paste a key from the Anthropic Console, and click Save & verify.
3. Verification makes one minimal Messages call on your key against claude-opus-5. Agents run on Claude models, so the key's organization needs access to them. On success the card shows Enabled and new sessions route to your key.

A saved key never routes until it verifies. Verify re-runs the check at any time; if Anthropic rejects the key (revoked, out of quota, missing model access), routing is disabled rather than left to fail mid-session. One provider routes at a time: verifying an Anthropic key disconnects an enabled Bedrock connection.

The key is stored write-only: no API response or dashboard surface ever returns it (the card shows the last 4 characters), and it never enters a sandbox. Model calls are forwarded to Anthropic with your key server-side, so your organization's rate limits apply; size your tier to your agent traffic. There is no silent fallback: if your key is removed or disabled while a session is running, its model calls fail with an error naming the cause instead of quietly moving back to an Ellipsis key.

To rotate, click Replace key, paste the new key, and Save & verify; new sessions use it immediately. To disconnect, click Remove; new sessions return to Ellipsis-managed keys.

Billing consequences

The token line of your Ellipsis bill drops to zero; Anthropic bills you for tokens directly, against your credits and commitments. Sandbox compute and the platform fee are unchanged: the fee is computed on actual usage (tokens plus compute) whether or not the tokens run on your key.

Session cost breakdowns still show real token spend, so spend limits keep working: a session that reaches its budget stops, even though the tokens are billed to your Anthropic account. Cached model responses are served without calling Anthropic, so repeated identical calls (replays, retries) cost nothing on your key.