fielding_skill

This skill helps you design durable REST APIs by applying Fielding's constraints to ensure statelessness, hypermedia, caching, and uniform interfaces.

Python

3

GitHub Stars

1

Bundled Files

2 months ago

Catalog Refreshed

4 months ago

First Indexed

Readme & install

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Installation

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npx veilstrat add skill copyleftdev/sk1llz --skill fielding

SKILL.md4.0 KB

Overview

This skill helps you design network-based software architectures using Roy Fielding's REST principles. It emphasizes the web constraints that yield scalability, modifiability, and visibility: statelessness, cacheability, uniform interfaces, layered systems, and HATEOAS. Use it to critique API designs and produce architectures meant to endure for decades.

How this skill works

I inspect API designs and system architectures against Fielding's constraints, looking for violations like session state on the server, RPC tunnelling over HTTP, missing hypermedia, incorrect cache semantics, and improper status-code usage. I recommend concrete fixes: resource-first modeling, media-type versioning, explicit Cache-Control and Link headers, and embedding HATEOAS links so clients navigate via hypermedia. I also evaluate whether intermediaries (CDNs, proxies) can be inserted without breaking clients.

When to use it

Designing public or long-lived web APIs that must remain stable and evolvable
Performing architectural reviews for web services or microservices
Migrating RPC-style APIs to resource-oriented RESTful designs
Defining API contracts and media types for backward-compatible evolution
Optimizing APIs for caching and intermediate layers

Best practices

Model APIs as resources (nouns) and use standard HTTP verbs for actions
Make every request self-descriptive; avoid server-side sessions and opaque client coupling
Return explicit caching headers and use content negotiation with media types for versioning
Provide HATEOAS links in responses so clients discover actions and URIs dynamically
Use proper HTTP status codes and Link headers for documentation and relations

Example use cases

Critique an existing API and get a prioritized list of REST constraint violations and fixes
Design a new Level-3 REST API with media-type versioning and full hypermedia controls
Audit system architecture for session-state leakage and recommend stateless alternatives
Create response schemas that include _links and Cache-Control headers to enable caching proxies
Convert RPC-style endpoints into resource-oriented endpoints and migration steps

FAQ

No. REST is an architectural style independent of any single protocol, though HTTP is its most common mapping and I focus on applying Fielding's constraints to HTTP APIs.

How do I version an API without breaking clients?

Prefer media-type versioning (Accept/Content-Type) and evolve representations while keeping entry points stable; use hypermedia so clients discover capabilities rather than hardcoding URLs.

Is HATEOAS required for all APIs?

For long-lived, evolvable public APIs, yes—HATEOAS decouples clients from URL structures. For internal or short-lived services, pragmatic trade-offs may apply.