API Cheat Sheet Wiki
Developer API references with practical debugging notes and tool links for status codes, headers, auth, CORS, webhooks, OpenAPI, and JSON Schema.
HTTP Status Codes
Lookup common API status codes and what clients should do next.
HTTP Headers
Common request and response headers for caching, auth, content negotiation, and tracing.
MIME Types
Content-Type values for APIs, uploads, browsers, and static files.
CORS
Browser cross-origin request rules, preflight behavior, and safe server headers.
JWT Claims
Common JWT registered claims and debugging rules.
OAuth Scopes
Permission strings used to limit what an access token can do.
Webhook Signatures
How APIs sign webhook payloads and how receivers verify them.
Rate Limit Headers
Headers that tell clients remaining quota and reset windows.
OpenAPI
Machine-readable API description format for endpoints, schemas, auth, and examples.
JSON Schema
Validation vocabulary for JSON structure, types, formats, and constraints.
Regex API Validation
Use regex safely for request validation without blocking valid users.