api-design SKILL.md skillA

api-design from d-padmanabhan/agent-engineering-handbook is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

mdr add d-padmanabhan/agent-engineering-handbook/api-design@git:20260906.0766fec

Pins git:20260906.0766fec in mdr.lock. Pin the fingerprint instead.

Audit grade

A, 17 of 17 checks passed

Kind

SKILL.md skill

Repository

d-padmanabhan/agent-engineering-handbook

Path

skills/api-design/SKILL.md

Versions recorded

1

Latest version

git:20260906.0766fec, committed Sep 6, 2026

Size

8,298 bytes

Repository stars

20

License

MIT

Designs and reviews production APIs across REST/HTTP, OpenAPI, GraphQL, gRPC, webhooks, asynchronous operations, batch endpoints, SSE, and WebSockets. Use when defining resources, routes, methods, status codes, problem details, pagination, idempotency, conditional writes, API schemas, compatibility, deprecation, authentication, authorization, rate limits, or protocol contracts.

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

# API Design

Mandatory API gates are owned by the API rule
(`${HANDBOOK_ROOT}/rules/320-api-design.mdc`). This skill owns design workflow,
trade-offs, examples, and protocol-specific guidance.

## Non-Negotiables

- Design from consumers, business invariants, trust boundaries, and failure
  behavior before choosing endpoint shapes.
- Let resource identifiers name nouns and protocol operations express behavior.
  Model a business action as a subordinate resource when that produces a clear
  lifecycle.
- Follow HTTP safety, idempotency, cache, conditional-request, and status-code
  semantics. Idempotence means the intended server effect is stable, not that
  every response is byte-identical.
- Authenticate the principal and authorize every protected object, tenant,
  relationship, field, and action on the server.
- Validate and bound every path, query, header, cookie, message, and body input.
  Serialize responses from allowlisted schemas rather than persistence objects.
- Use RFC 9457 Problem Details for new public HTTP error contracts unless an
  existing compatibility commitment requires another documented shape.
…

Read the whole file at its exact version.

How to install

mdr add d-padmanabhan/agent-engineering-handbook/api-design@sha256:ddfbb41539b6a550

[![mdr](https://markdownregistry.com/badge/art_qpjivlhltmmtswoy.svg)](https://markdownregistry.com/a/art_qpjivlhltmmtswoy)

Versions

The registry has recorded 1 version of this file, committed on Sep 6, 2026.

Audit of the latest version

Source

API

GET https://markdownregistry.com/api/v1/artifacts/art_qpjivlhltmmtswoy
GET https://markdownregistry.com/api/v1/resolve?ref=d-padmanabhan/agent-engineering-handbook/api-design
GET https://markdownregistry.com/api/v1/blob/ddfbb41539b6a550e1ce1743bc567f30991dbef2ca8ed23d1cffeda712b3ae46

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

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