Keychains.dev is a secure credential proxy designed specifically for AI agents that need to interact with APIs. It enables AI agents to access any API without leaking sensitive credentials by acting as an intermediary layer that handles authentication securely.

Keychains.dev functions as a drop-in replacement for curl commands, where developers replace hard-coded credentials with template variables like {{GITHUB_TOKEN}} or {{STRIPE_PRIVATE_KEY}}. The system supports thousands of API providers including GitHub, Google, Slack, Stripe, Notion, Linear, Spotify, Uber, Airtable, Shopify, Twilio, and OpenAI. It handles various authentication methods including OAuth 2.0 with PKCE, API keys, and basic auth with automatic token refresh capabilities.

The security model is built around SSH key identity authentication where every machine authenticates via SSH keypairs instead of passwords or API keys. Credentials are injected server-side so agents never see raw secrets, making them immune to prompt injection attacks. The system uses stateful fingerprinting where machines exchange fingerprints with every call, and leaked keys are invalidated on first use.

Users benefit from full transparency and control, seeing every permission granted to each agent with a complete audit trail. They can approve new API scopes with one click and revoke any machine's access instantly without waiting periods. The system allows safe delegation through scoped delegate tokens that give sub-agents only necessary permissions or blank tokens that require fresh user approval.

The product targets developers building AI agents that need secure API access, providing agent-specific security primitives including SSH-based machine identity, user consent flows, and multi-agent delegation capabilities designed specifically for autonomous agents rather than traditional microservices.