Authentication is one of the trickiest parts of building agent workflows. Agents need auth providers with machine-friendly onboarding, clear API keys, and no surprise CAPTCHA or phone verification. Here are the top auth tools rated by the Agent Native Registry.
3 tools rated · Agent Native Score (0–100) · Last updated March 2026
Open source Firebase alternative. Postgres database, auth, storage, edge functions, and realtime subscriptions.
Official MCP server is well-maintained. Free tier includes 500MB database, 1GB storage. Branching feature is excellent for agent workflows. REST API auto-generated from schema.
Authentication and user management. Drop-in UI components, JWT sessions, organizations, and a complete Backend API.
Backend API is well-suited for agents managing users programmatically. Free tier up to 10,000 MAUs is generous. Good documentation. Better than Auth0 for agent use cases due to simpler Backend API.
Identity and access management platform. OAuth 2.0, SAML, MFA, and enterprise SSO in a managed service.
Management API is powerful but complex. Machine-to-machine apps (for agents) count toward the free tier limit of 1000/month. Complex setup relative to Clerk. Free tier recently became more restrictive.
Add to your Claude Code, Cursor, or Windsurf config and your agents will automatically know which tools to use.
{
"mcpServers": {
"agent-native-registry": {
"type": "http",
"url": "https://anr-eight.vercel.app/api/mcp"
}
}
}