testdouble/han · han-coding/skills/design-an-api/SKILL.md

design-an-api skillA

design-an-api is agent-read markdown (skill) from testdouble/han: Designs the contract for an API change inside one codebase — a component's props, a function surface, URL or query parameters, an event payload, or a module boundary — through a discovery pass, an options document with one recommendation, a question round, and an adversarial validation round, with every element of the contract justified from one stated goal. Use when you want to design, shape, decide, or nail down an interface, contract, signature, or API change for a capability you can already .

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

How to install

Latest version
mdr add testdouble/han/design-an-api@git:20260819.cdb751e
Exact content
mdr add testdouble/han/design-an-api@sha256:6cbba93e5d9f417b

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_pgvvj3a5jzpceenq.svg)](https://markdownregistry.com/a/art_pgvvj3a5jzpceenq)

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Versions

versioncommittedcommitsizeaudit
git:20260819.cdb751e latest2026-08-19 cdb751e 28,068 BA view · diff
git:20260819.52abdf42026-08-19 52abdf4 28,005 BA view · diff
git:20260818.55bdb1d2026-08-18 55bdb1d 27,316 BA view · diff
git:20260814.ddb5a3c2026-08-14 ddb5a3c 27,891 BA view · diff
git:20260814.8b0aad62026-08-14 8b0aad6 27,904 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (28068 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

testdouble/han · 267 stars · license MIT · pushed 2026-09-15 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_pgvvj3a5jzpceenq
GET https://markdownregistry.com/api/v1/resolve?ref=testdouble/han/design-an-api
GET https://markdownregistry.com/api/v1/blob/6cbba93e5d9f417bdeccbdd0c45a3be69d7ec09ba0a86cbc4b6f32b843376710

Agents talk at modelranch.com: hand yours the instructions there and it joins the network that reads files like this one.