api-builder

api-builder is a skill for Claude Code, Codex from amanning3390/hermeshub. It costs 41 tokens per session (457 once invoked), scanned A, original, MIT.

A workflow for designing, scaffolding, and documenting REST or GraphQL APIs. An API is an interface that lets software exchange data and actions; OpenAPI is a standard format for describing its endpoints.

In plain words
What is it for?
Use it to plan resources and endpoints, create an OpenAPI 3.0 specification, scaffold Express, FastAPI, or Flask services, and prepare API documentation and fixtures.
Why use it?
It turns requirements into a defined API structure, starter backend code, validation, error handling, documentation, and test data.

Skill for Claude CodeCodex

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/amanning3390/hermeshub/api-builder
Any agent
npx skills add amanning3390/hermeshub --skill api-builder
Clone the repo
git clone --depth 1 https://github.com/amanning3390/hermeshub

Made for: Claude Code, Codex.

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-builder

README.md
[![agentmods](https://agentmods.dev/badge/skills/amanning3390/hermeshub/api-builder.svg)](https://agentmods.dev/skills/amanning3390/hermeshub/api-builder)
Your own site
<a href="https://agentmods.dev/skills/amanning3390/hermeshub/api-builder"><img src="https://agentmods.dev/badge/skills/amanning3390/hermeshub/api-builder.svg" alt="Measured on agentmods" height="20"></a>
Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 457 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 $0.00041 $0.00457
Opus 5 $0.00020 $0.00229
Sonnet 5 $0.00008 $0.00091
Haiku 4.5 $0.00004 $0.00046

Measured 4d ago against content hash cde21666de86, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

api-builder 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 4d 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-builder/SKILL.md · 65 lines

What it actually says

API Builder

End-to-end API design, scaffolding, and documentation.

When to Use

  • User wants to create a new API
  • User needs endpoints for a specific domain
  • User wants OpenAPI/Swagger documentation
  • User asks for API scaffolding or boilerplate

Procedure

  1. Gather requirements: resources, operations, auth model
  2. Design the API schema (resources, relationships, endpoints)
  3. Generate OpenAPI 3.0 spec
  4. Scaffold route handlers with validation
  5. Add error handling and middleware
  6. Generate documentation
  7. Create test fixtures

Supported Frameworks

  • Express (Node.js): express + zod + swagger-jsdoc
  • FastAPI (Python): automatic OpenAPI generation
  • Flask (Python): flask-restx or flask-smorest

REST Conventions

  • GET /resources — list all
  • POST /resources — create one
  • GET /resources/:id — get one
  • PATCH /resources/:id — update one
  • DELETE /resources/:id — delete one

Best Practices

  • Consistent error response format
  • Pagination for list endpoints
  • Rate limiting middleware
  • Request validation on all inputs
  • CORS configuration
  • Authentication middleware

Pitfalls

  • Don't expose internal IDs in public APIs
  • Always validate request bodies
  • Version your API (v1, v2) from the start
  • Don't return sensitive data in error messages

Verification

  • All endpoints respond with correct status codes
  • Validation rejects malformed input
  • Documentation renders correctly
  • Auth middleware blocks unauthorized requests
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. 4d ago First seen · 65 lines · 41 tokens per session scan A cde21666de86

Subscribe to this mod's changes

api-builder is a skill published in the GitHub repository amanning3390/hermeshub (34 stars, last pushed 2mo ago), licensed MIT. It adds 41 tokens to every session and 457 once invoked, about $0.0002 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.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

brainstorming

You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation.

obra/superpowers · 37 tokens

auto-perf-optimize

Run agent-driven VS Code performance or memory investigations. Use when asked to launch Code OSS, automate a VS Code scenario, run the Chat memory smoke runner, capture renderer heap snapshots, take workflow screenshots, compare run summaries, or drive a repeatable scenario before heap-snapshot analysis.

microsoft/vscode · 62 tokens

chat-perf

Run chat perf benchmarks and memory leak checks against the local dev build or any published VS Code version. Use when investigating chat rendering regressions, validating perf-sensitive changes to chat UI, or checking for memory leaks in the chat response pipeline.

microsoft/vscode · 51 tokens

chat-pet-sprite-creation

Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.

microsoft/vscode · 53 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens