# API And Interface Design

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- Skill: `viasrijan/api-and-interface-design` (Agent Skill)
- Install (CLI): `npx skillmds@latest add viasrijan/api-and-interface-design`
- Raw SKILL.md: https://api.skillmd.com/api/skills/viasrijan/api-and-interface-design/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: viasrijan (https://skillmd.com/u/viasrijan)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/viasrijan/api-and-interface-design

---

---
name: api-and-interface-design
description: "Use when designing APIs or module boundaries — contract-first, Hyrum Law, error semantics."
---

# api-and-interface-design

Contract-first API design.

## When to use

See description.

## Workflow

1. Understand the task and check project context.
2. Follow the source skill steps for this domain.
3. Verify output and commit.

## Verification

- [ ] Task completed per source skill checklist
- [ ] Tests pass and no regressions

## References

- Source: upstream composite