Access Token
An access token is a credential that authorizes calls to a protected API on behalf of a user or application. OAuth providers issue access tokens with a limited lifetime and scopes. APIs validate the token signature or call an introspection endpoint before executing the request.
Technical Architecture & Deep-Dive
Access tokens may be JWTs with embedded claims or opaque strings meaningful only to the issuer. Clients send them as bearer tokens in the Authorization header. Short expirations limit damage if exfiltrated, while scopes restrict which resources and actions each token may perform.
Public clients should receive narrowly scoped tokens from an edge layer rather than upstream admin credentials. Gateways verify expirations, audiences, and issuer signatures at the edge, then attach separate upstream secrets only inside trusted infrastructure.
Key Architectural Benefits
Implement Access Token at the Edge
Deploy lightweight API aggregation, edge caching, and secret injection in minutes without Docker containers or complex servers.
Frequently Asked Questions
Q:What happens when an access token expires mid-request?
The API returns 401. Clients should refresh using a secure server-held refresh token or prompt re-authentication instead of embedding long-lived secrets.
Related Architecture Concepts
A refresh token is a long-lived OAuth credential used only to obtain new access tokens without asking the user to sign in again. Refresh tokens are highly sensitive: anyone who steals one can mint fresh access tokens until the refresh token is revoked or expires.
A bearer token is an access credential sent in the HTTP Authorization header as Bearer followed by the token. Whoever bears, or holds, the token is granted access, without additional proof of identity, so bearer tokens must be transmitted only over HTTPS and kept confidential.
OAuth scopes are named permission strings that define what an access token is allowed to do, such as read contacts or write payments. During authorization, the user or admin approves requested scopes, and the issued token carries only those grants.
A JSON Web Token (JWT) is a compact, URL-safe token containing a JSON payload of claims, such as user ID and expiration, signed by the issuer. Servers verify the signature to trust the claims without a database lookup, enabling stateless authentication.
Ready-to-Use Edge Recipes
You should not store Intercom credentials in React client code. Intercom contacts and events via edge proxy with server-side Bearer token. RealComposer Secret Vault injects headers on Cloudflare Workers so only your edge URL is public.
You should not store Salesforce credentials in React client code. Vault-inject OAuth or integration tokens at the edge; React calls one public client token URL. RealComposer Secret Vault injects headers on Cloudflare Workers so only your edge URL is public.
To solve call github api with private personal access token from client, never execute unauthenticated requests or embed private tokens directly in client bundles. RealComposer acts as a sub-10ms edge gateway running on Cloudflare Workers that securely injects credentials from your Secret Vault, normalizes responses, and prevents unauthorized API usage. Route calls through your RealComposer edge URL to guarantee complete privacy, robust origin validation, and low mobile latency.