{"name":"Firebase Auth","slug":"firebase-auth","category":"auth","type":"cloud","website":"https://firebase.google.com/products/auth","pricing":"freemium","pricing_tiers":["Free up to 50k MAU","Blaze pay-as-you-go","Phone auth: 10¢/verification"],"open_source":false,"self_hosted":false,"sdk_languages":["javascript","typescript","python","java","swift","kotlin","go"],"frameworks":["langchain","vercel-ai"],"agent_features":{"agent_sdk":false,"token_delegation":false,"human_in_the_loop":false,"fga":false,"mcp_support":null,"async_authorization":false},"compliance":["soc2","gdpr"],"best_for":"Rapid prototyping and Google-native stacks; low-friction auth for AI apps that don't need agent-specific authorization","limitations":"No token delegation, no FGA, no agent SDK; vendor lock-in to Google Cloud; limited authorization model","verified_by":"editorial","last_verified":"2026-04-17","source_urls":{"changelog":"https://firebase.google.com/support/release-notes/js","pricing":"https://firebase.google.com/pricing","docs":"https://firebase.google.com/docs/auth"},"feature_labels":{"agent_sdk":"Dedicated SDK for agentic workflows — agent sessions, token lifecycle, and authorization requests","token_delegation":"Issue scoped tokens an agent can use downstream without exposing user credentials","human_in_the_loop":"Pause agent execution and require explicit user approval before proceeding","fga":"Fine-Grained Authorization — relationship-based or attribute-based access control, not just role-based","mcp_support":"Native OAuth/OIDC authorization layer for Model Context Protocol servers","async_authorization":"Non-blocking approval workflows — agent continues and gets notified when approval is granted"},"comparisons":[{"slug":"auth0-vs-firebase-auth","title":"Auth0 vs Firebase","vs":"auth0"},{"slug":"clerk-vs-firebase-auth","title":"Clerk vs Firebase","vs":"clerk"},{"slug":"cognito-vs-firebase-auth","title":"Amazon Cognito vs Firebase","vs":"cognito"},{"slug":"descope-vs-firebase-auth","title":"Descope vs Firebase","vs":"descope"},{"slug":"firebase-auth-vs-keycloak","title":"Firebase Auth vs Keycloak","vs":"keycloak"},{"slug":"firebase-auth-vs-ory","title":"Firebase Auth vs Ory","vs":"ory"},{"slug":"firebase-auth-vs-stytch","title":"Firebase vs Stytch","vs":"stytch"},{"slug":"firebase-auth-vs-supabase-auth","title":"Firebase Auth vs Supabase Auth","vs":"supabase-auth"},{"slug":"firebase-auth-vs-workos","title":"Firebase Auth vs WorkOS","vs":"workos"}],"body":"# Firebase Auth\n\nFirebase Auth is a common starting point for AI app prototypes and projects running on Google Cloud. Setup is fast, the SDKs are widely documented, and it integrates naturally with other Firebase and GCP services.\n\nFor basic AI applications — a user logs in, an LLM API is called in their session — Firebase Auth is adequate and friction-free. The problems emerge when agentic requirements arise: Firebase has no token delegation, no FGA, no human-in-the-loop support, and no agent-specific SDK.\n\nFirebase ID tokens can be used to authenticate requests to backend services, but the authorization model is limited to Firebase's built-in rules and custom claims. For complex agent authorization patterns, teams typically end up building authorization logic in application code rather than relying on the identity layer.\n\nMigration away from Firebase Auth is also non-trivial, which is worth considering before committing to it for an agentic architecture.\n\n**Agent-specific features:**\n- Firebase ID tokens for backend API authentication\n- Custom claims for coarse-grained authorization\n- Service account authentication for backend agents\n- Integrates with Google Cloud IAM for GCP resource access"}