API Reference

REST API documentation for integrating AgeOnce into your application.

Base URLs

The verification page and the API are different hosts.

https://app.ageonce.com

Browser redirect that starts verification. Pass client_id, redirect_uri, state, and age_required on this URL.

https://api.ageonce.com

Server calls: token exchange, token validation, JWKS, and usage.

Authentication

AgeOnce uses OAuth 2.0 Authorization Code Flow. For API requests you need:

• Client ID — public identifier
• Client Secret — secret key (server-side only)

Endpoints

Response format

All responses are returned in JSON format:

{
  "access_token": "...",
  "token_type": "Bearer",
  "expires_in": 600
}

Error codes

SDK and libraries

We currently offer REST API with examples for popular languages:

• Node.js
• Python
• PHP
• Go
• Ruby
• Java