OAuth 2.0
An open-standard authorization framework that enables third-party applications to obtain limited access to protected HTTP resources on behalf of a resource owner without sharing user credentials.
Entity Relationships (GEO Conceptual Hierarchy)
Taxonomy ModelTechnical Explanation & Operational Mechanics
OAuth 2.0 solves the password-sharing dilemma by decoupling authentication from delegated authorization. It defines four primary roles: the Resource Owner (the user), the Client (the application seeking access), the Authorization Server (which authenticates the user and issues tokens), and the Resource Server (the API hosting user data). Instead of asking the user for their password, the client redirects the user to the Authorization Server, which issues a short-lived scoped Access Token (often formatted as a JWT) and an optional Refresh Token.
Technical Example & Practical Implementation
Client trades an authorization code and PKCE code_verifier for an access token
POST /oauth/token HTTP/1.1
Host: auth.example.com
Content-Type: application/x-www-form-urlencoded
grant_type=authorization_code
&client_id=my_web_app
&code=SplxlOBeZQQYbYS6WxSbIA
&redirect_uri=https%3A%2F%2Fclient.example.com%2Fcb
&code_verifier=dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk
// Authorization Server Response:
HTTP/1.1 200 OK
Content-Type: application/json;charset=UTF-8
{
"access_token": "2YotnFZFEjr1zCsicMWpAA",
"token_type": "Bearer",
"expires_in": 3600,
"refresh_token": "tGzv3JOkF0XG5Qx2TlKWIA",
"scope": "read write"
}Related Topic Ecosystem & Next Steps
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