design-an-interface SKILL.md skillA
design-an-interface from chrislacey89/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add chrislacey89/skills/design-an-interface@git:20260408.27121d1Pins git:20260408.27121d1 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- chrislacey89/skills
- Path
design-an-interface/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260408.27121d1, committed Apr 8, 2026
- First version recorded
- Apr 7, 2026
- Size
- 4,985 bytes
- Repository stars
- 4
- License
- MIT
Invoked helper skill for unresolved module boundaries, usually called from /write-a-prd. Use to compare multiple interface shapes for a module or component when caller ergonomics and surface area are still unclear. Not for API contract review or already-settled designs.
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
# Design an Interface Based on "Design It Twice" from "A Philosophy of Software Design": your first idea is unlikely to be the best. Generate multiple radically different designs, then compare. ## Invocation Position This is an invoked helper skill. It normally runs from `/write-a-prd` when a module boundary is still unresolved, and it can also support refactor or architecture work when interface tradeoffs are the main uncertainty. Use it when the open question is the shape of a module interface: method count, surface area, depth, caller ergonomics, or evolvability. Do not use it when the real uncertainty is the API contract itself — that belongs in `/api-design-review` — or when the work is already clear enough to keep shaping or implementing without a design fork. ## Workflow ### 1. Gather Requirements Before designing, understand: - [ ] What problem does this module solve? - [ ] Who are the callers? (other modules, external users, tests) - [ ] What are the key operations? - [ ] Any constraints? (performance, compatibility, existing patterns) - [ ] What should be hidden inside vs exposed? Ask: "What does this module need to do? Who will use it?" …
Read the whole file at its exact version.
How to install
mdr add chrislacey89/skills/design-an-interface@sha256:f140430c24680e17The line at the top of this page pins the label git:20260408.27121d1, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_rynqbf7hwiq3itaq)
5 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Apr 7, 2026 and Apr 8, 2026, more than one a day.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260408.27121d1 latest | 2026-04-08 | 27121d1 | 4,985 B | A | view · diff |
| git:20260407.d6d717b | 2026-04-07 | d6d717b | 4,960 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (4985 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
chrislacey89/skills · 4 stars · license MIT · pushed 2026-10-22 · branch prod
API
GET https://markdownregistry.com/api/v1/artifacts/art_rynqbf7hwiq3itaq GET https://markdownregistry.com/api/v1/resolve?ref=chrislacey89/skills/design-an-interface GET https://markdownregistry.com/api/v1/blob/f140430c24680e178ed676b0c332196b5ebd5422cc1a0b644b3d50624b12b602
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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