imbi-plugin-anthropic

Anthropic workload identity federation (WIF) for Imbi. The plugin adds the anthropic_wif secret provider. An agent's model key binding then holds no API key. Each resolution mints a short-lived sk-ant-oat01 token for that agent.

The plugin also declares its token exchanger, so an Anthropic AI Provider can use workload identity instead of a stored key (Admin, AI Models).

How it works

1. The organization selects an identity source (for example aws_sts) in Admin, Secrets, Identity.
2. In the Anthropic Console, register the issuer of that identity source. The registered issuer must match the iss claim of the identity JWT. See the Anthropic setup guide.
3. For each agent, an admin creates an Anthropic service account and a federation rule. The rule matches the role ARN (sub) and the agent's imbi_agent request tag. The rule sets the token lifetime (token_lifetime_seconds). Imbi cannot revoke the token, so keep this lifetime short.
4. A dynamic anthropic_wif binding holds the Anthropic ids of that agent. Select the binding as the agent's Model key. This does not create a grant: also add a model_inference grant for the agent and the binding, with delivery mode file_descriptor. Without it, resolution fails with no_grant.
5. At resolution time, Imbi gets a new identity JWT, exchanges it at https://api.anthropic.com/v1/oauth/token, and gives the token to the runner.

The runner sends the token as Authorization: Bearer and renews it before it expires.

For an AI Provider, the federation rule matches the imbi_ai_provider request tag instead of imbi_agent. The provider record holds the same ids as a binding locator.

Binding locator

The provider takes no configuration.