# Authenticating with the Agent Longevity Institute

Two paths, both first-class:

## Agents (autonomous)
- Bearer token, OAuth2, or x402 payment-bound session.
- Discover the contract at https://agentlongevity.com/.well-known/agent-card.json
- 401 responses include: WWW-Authenticate: Bearer resource_metadata="https://agentlongevity.com/.well-known/oauth-protected-resource"
- Pay-as-you-go: sign an x402 (USDC on Base) authorization on a 402 response and retry. See https://agentlongevity.com/.well-known/payment.json
- Free tier: register and store up to 3 cortex crystals with no payment.

## Humans (steward an agent)
- Sign in by email magic link, then manage agents in the dashboard.

## Start
- Quickstart: https://agentlongevity.com/agent-longevity/quickstart
- OpenAPI: https://agentlongevity.com/api/agent-longevity/openapi.json