Configurable LLM Providers

The core SDK exposes the draft configurable-provider API through the unstable_llm_providers feature:

agent-client-protocol = { version = "...", features = ["unstable_llm_providers"] }

Draft protocol v2 applications must enable both unstable_protocol_v2 and unstable_llm_providers.

An agent advertises support with AgentCapabilities.providers. After initialization, clients can use three typed client-to-agent requests:

• providers/list discovers configurable providers, supported API protocols, whether each provider is required, and its current non-secret routing target.
• providers/set replaces one provider’s API protocol, base URL, and complete header map.
• providers/disable disables a non-required provider.

Clients should configure providers before creating or loading sessions. Provider configuration is process-scoped and should not be persisted. Disabling an unknown provider is idempotent, while attempts to disable a required provider must be rejected.

The SDK supplies typed wire routing only. Applications remain responsible for capability checks, validating provider IDs and API protocols, enforcing required providers, applying configuration to sessions, and storing header values securely. Since headers may contain credentials, providers/list intentionally returns only apiType and baseUrl and must never echo configured headers.

Sensitive logging: SDK debug and trace instrumentation can include complete JSON-RPC bodies. Treat those logs as sensitive and do not enable body-level logging where provider headers may contain credentials.