Design-first approach
A specification-first approach defines and validates an interface or behavioral contract before implementing the system that conforms to it.
Automating API Delivery
An API development practice that iteratively creates and validates an API definition before implementing the API in code.
- How it is used
- Establishes an agreed API definition for consumer validation before implementation and for parallel backend, testing, and client work afterward.
- How deep it goes
- Describes iterative definition, mocking, review, approval, and implementation handoff, without prescribing a single universal design-review procedure.
- Examples
- Uses a Product Catalog API operations table and approval by pull-request merge or review-ticket status change.
- What you can do after
- Practice/perform consumer validation and explicit design approval before coordinating parallel implementation against an agreed API definition.
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The Design of Web APIs, Second Edition
A specification-first approach is an API development method in which the API specification is authored before or alongside implementation code.
- How it is used
- Uses an independent OpenAPI document to design, describe, discuss, and validate a REST API before implementation.
- How deep it goes
- Explains source-of-truth trade-offs, editor selection, and document structure, but defers implementation-framework details.
- Examples
- Uses /products, OpenAPI editors, Swagger Editor Next, and a comparison of specification-first and code-first trade-offs.
- What you can do after
- Author and evaluate an OpenAPI contract independently, then use it to check exposed operations and document HTTP behavior.
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Related concepts
- code-first approachcontrasts with · A code-first approach defines a system, model, or contract in source code before deriving or finalizing its schema or specification.
- OpenAPI specificationuses · The OpenAPI Specification is a standard, machine-readable format for describing HTTP APIs, including their operations, inputs, outputs, data structures, and security requirements.
- APIOpspart of · APIOps is the practice of automating the governance, delivery, and operation of API products across their life cycle.
- api-first architecturecontrasts with · An approach that treats APIs as primary product interfaces by specifying their contracts as a foundation for implementing the services and clients that use them.
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