What is OpenAPI Contract?
A machine-readable spec describing every route, schema, and error so clients and tests generate from truth. BYOB treats the OpenAPI file as the API contract: code, docs, and mocks all derive from it.
Related terms
REST Resource Design
Modeling an API as nouns with stable URLs — /projects/:id/messages — instead of action endpoints. Resource design makes caching, auth scoping, and client reasoning predictable across every route.
Error Envelope
A consistent failure shape — code, message, details, and request id — returned by every endpoint. Envelopes let clients handle errors programmatically instead of parsing unpredictable prose per route.
API Versioning
Evolving an API without breaking existing clients: versioned paths or headers, additive changes first, removals on a schedule. Versioning is a promise that yesterday’s integration keeps working tomorrow.
Idempotent HTTP Verbs
GET, PUT, and DELETE produce the same result when safely retried; POST does not promise that. BYOB server routes use idempotent verbs for mutations clients may repeat after network timeouts.
Retry, Backoff & Jitter
Retrying failed calls after growing delays with random spread, so a fleet does not stampede a recovering service. Exponential backoff plus jitter turns synchronized thundering herds into gentle background noise.
Dead-Letter Queue
A holding area for messages that exhausted every retry, preserved with full context for inspection. Dead letters stop poison events from blocking healthy traffic and give operators a deliberate replay path.