api-design

api-design is a skill for Claude Code from ivegamsft/basecoat. It costs 76 tokens per session (305 once invoked), scanned A, original, MIT.

A guide for designing and reviewing API contracts, including REST and GraphQL interfaces. It covers request and response shapes, versioning, breaking changes, deprecation, and governance.

In plain words
What is it for?
Use it to draft OpenAPI or GraphQL designs, review contract changes, choose versioning approaches, and plan API deprecation.
Why use it?
It helps teams agree on how software services communicate before code is written. This reduces integration problems and unexpected changes for API consumers.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to draft OpenAPI or GraphQL designs, review contract changes, choose versioning approaches, and plan API deprecation.

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Install with agentmods
npx agentmods add skills/ivegamsft/basecoat/api-design
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/ivegamsft/basecoat/api-design
Any agent
npx skills add ivegamsft/basecoat --skill api-design
Clone the repo
git clone --depth 1 https://github.com/ivegamsft/basecoat

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for api-design

README.md
[![agentmods](https://agentmods.dev/badge/skills/ivegamsft/basecoat/api-design.svg)](https://agentmods.dev/skills/ivegamsft/basecoat/api-design)
Your own site
<a href="https://agentmods.dev/skills/ivegamsft/basecoat/api-design"><img src="https://agentmods.dev/badge/skills/ivegamsft/basecoat/api-design.svg" alt="Measured on agentmods" height="20"></a>
Per session 76 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 305 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00076 $0.00305
Opus 5 $0.00038 $0.00152
Sonnet 5 $0.00015 $0.00061
Haiku 4.5 $0.00008 $0.00030

Measured 3d ago against content hash a62b13a478ff, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

api-design scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/api-design/SKILL.md · 29 lines

What it actually says

API Design Skill

Design new API contracts, review spec changes for breaking changes, choose versioning strategies, and enforce API governance standards.

Templates in This Skill

Template Purpose
openapi-template.md OpenAPI 3.x skeleton for a new REST API resource with CRUD, pagination, and error envelopes
breaking-change-checklist.md Checklist for evaluating whether a spec change is breaking, with mitigation guidance
versioning-decision-tree.md Decision tree for choosing the right versioning action for a given change
api-governance-checklist.md Governance checklist every API spec must pass before approval

Agent Pairing

Use with api-designer agent. For implementation hand off to backend-dev; for data models coordinate with data-tier; share the spec with frontend-dev for consumer integration.

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 29 lines · 76 tokens per session scan A a62b13a478ff

Subscribe to this mod's changes

api-design is a skill published in the GitHub repository ivegamsft/basecoat (4 stars, last pushed 2d ago), licensed MIT. It adds 76 tokens to every session and 305 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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