Request Schema

Overview

A Request Schema defines the permitted structure, data types, formats, required fields, constraints, and nested objects of an API request. It can be expressed through OpenAPI and JSON Schema-compatible constructs. Testing Request Schema should cover malformed input, denied access, rate limits, timeouts, duplicates, asynchronous completion, and version changes.

The main risks include accepting ambiguous data, rejecting backward-compatible clients, unsafe coercion, unbounded payloads, and undocumented null behavior. It describes syntactic and structural validity, while business rules may impose additional constraints that cannot be represented fully in the schema.

In production, teams should define ownership and apply required-field rules, numeric and string constraints, enumerations, format checks, additional-property policy, examples, and versioning. Data handled by Request Schema should use documented types, units, timestamp rules, nullable fields, and enum behavior to prevent silent interpretation errors.

Useful measures include validation failure rate, unknown-field rate, schema coverage, breaking-change count, and malformed request incidents. Request Schema is closely connected to Response Schema, Schema Validation, and OpenAPI Document. A successful transport result from Request Schema should not be interpreted beyond the exact API state documented by the provider.

The Request Schema contract should define identifiers, validation, authorization, status semantics, errors, limits, and version behavior at the same boundary. For Request Schema, the application should preserve a correlation path from request construction through response, asynchronous completion, and final business state. Changes to Request Schema should be checked against older clients, stored payloads, enum growth, default behavior, and retry assumptions.

Observability for Request Schema should record operation, version, principal, request ID, latency, retry count, error code, and final state without exposing secrets.