React Native + Expo JWT Auth with FastAPI — A Complete Working Example

Short summary

A complete production-grade JWT auth flow for React Native + Expo with FastAPI, covering token issuance, secure device storage via expo-secure-store, axios interceptors for automatic refresh, and the type-claim check that prevents refresh tokens from being replayed as access tokens. Includes working Python and TypeScript code with hardening details most tutorials skip. The result keeps users logged in for weeks while limiting stolen token exposure to minutes.

• •Full JWT flow: login, secure storage, auto-refresh, token-type hardening
• •Code for FastAPI token minting with PyJWT and bcrypt, plus mobile-side interceptors
• •Covers production gaps most tutorials miss: replay prevention, passlib avoidance, keychain storage

Generated with AI, which can make mistakes.