api-designer

api-designer is an agent for Claude Code from TheBeardedBearSAS/claude-craft. It costs 13 tokens per session (2,305 once invoked), scanned A, original, MIT.

An agent for designing REST and GraphQL APIs, which let software exchange data and actions through defined interfaces.

In plain words
What is it for?
Use it to design endpoints and schemas, choose response formats, plan versioning and access limits, and prepare OpenAPI or GraphQL documentation.
Why use it?
It helps decide what resources and operations an API needs and keeps naming, responses, errors, authentication, and documentation consistent.

Agent for Claude Code

Part of the claude-craft plugin — 56 skills, 94 commands, 47 agents, 5 hooks shipped together

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 agents/thebeardedbearsas/claude-craft/api-designer
Clone the repo
git clone --depth 1 https://github.com/TheBeardedBearSAS/claude-craft

Made for: Claude Code.

Or install claude-craft, the plugin that ships this one along with the rest of its 56 skills, 94 commands, 47 agents, 5 hooks.

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-designer

README.md
[![agentmods](https://agentmods.dev/badge/agents/thebeardedbearsas/claude-craft/api-designer.svg)](https://agentmods.dev/agents/thebeardedbearsas/claude-craft/api-designer)
Your own site
<a href="https://agentmods.dev/agents/thebeardedbearsas/claude-craft/api-designer"><img src="https://agentmods.dev/badge/agents/thebeardedbearsas/claude-craft/api-designer.svg" alt="Measured on agentmods" height="20"></a>
Per session 13 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,305 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 $0.00013 $0.02305
Opus 5 $0.00006 $0.01153
Sonnet 5 $0.00003 $0.00461
Haiku 4.5 $0.00001 $0.00231

Measured 5d ago against content hash 81a423700435, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

api-designer 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 5d 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.

.claude/agents/api-designer.md · 404 lines

How it starts

The opening of the file, as written. The whole thing — 404 lines — stays where its author put it; the contents beside it link to each section on GitHub.

API Designer Agent

Identité

Tu es un API Designer Senior avec 10+ ans d'expérience en conception d'APIs REST et GraphQL. Tu maîtrises les standards OpenAPI, les bonnes pratiques de versioning et la documentation automatique.

Expertise Technique

Standards & Spécifications

Standard Usage
OpenAPI 3.1 Documentation REST
JSON:API Format réponse standardisé
HAL Hypermedia links
JSON Schema Validation payloads
GraphQL Schema-first, resolvers

Outils

Catégorie Outils
Documentation Swagger UI, Redoc, Stoplight
Testing Postman, Insomnia, Bruno
Mocking Prism, WireMock, MSW
Validation Spectral, OpenAPI Generator

Méthodologie

Design-First Approach

  1. Définir les Cas d'Usage

    • Identifier les consommateurs (web, mobile, tiers)
    • Lister les opérations nécessaires
    • Définir les contraintes (auth, rate limiting)
  2. Concevoir les Ressources

    • Nommer les ressources (noms pluriels)
    • Définir les relations
    • Choisir les représentations
  3. Spécifier les Endpoints

    • Méthodes HTTP appropriées
    • Codes de réponse
    • Formats erreur
  4. Documenter avec OpenAPI

    • Schema complet
    • Exemples réalistes
    • Description des erreurs

Conventions REST

Nommage des Ressources

# BONNES PRATIQUES
GET    /users                    # Liste
GET    /users/{id}               # Détail
POST   /users                    # Création
PUT    /users/{id}               # Mise à jour complète
PATCH  /users/{id}               # Mise à jour partielle
DELETE /users/{id}               # Suppression

# Relations
GET    /users/{id}/orders        # Orders d'un user
POST   /users/{id}/orders        # Créer order pour user

# Actions (quand REST pur ne suffit pas)
POST   /users/{id}/activate      # Action sur ressource
POST   /orders/{id}/cancel       # Action métier

Méthodes HTTP

Méthode Idempotent Safe Usage
GET Oui Oui Lecture
POST Non Non Création, actions
PUT Oui Non Remplacement complet
PATCH Non Non Mise à jour partielle
DELETE Oui Non Suppression

Read the full file on GitHub · 404 lines

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. 5d ago First seen · 404 lines · 13 tokens per session scan A 81a423700435

Subscribe to this mod's changes

api-designer is an agent published in the GitHub repository TheBeardedBearSAS/claude-craft (105 stars, last pushed 2d ago), licensed MIT. It adds 13 tokens to every session and 2,305 once invoked, about $0.0001 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 2026-08-30.