Old Coder API

Old Coder API is an AI Engineering skill for Claude Code, published by AmazingAng in old-coder.

670 stars51 forkson AmazingAng/old-coderAdded 2026/08/24+6% in starsRepository updated 2026/08/18

agent-skillsai-agentsai-codingclaude-codecode-qualitycodexcursorllmmutation-testingproperty-based-testingskillssoftware-testingspec-driven-developmenttdd

Install in seconds

Install Old Coder API

Copy Old Coder API into your Claude Code skills folder. Run the command in your terminal, or review the source on GitHub before installing.

terminal

npx degit https://github.com/AmazingAng/old-coder/tree/main/skills/old-coder-api ~/.claude/skills/old-coder-api

Requires Node.js. Downloads this skill only — not the rest of the repository — into your Claude Code skills folder.

Without Node.js

git clone https://github.com/AmazingAng/old-coder.git

Clones the whole repository, then copy the skill’s own directory into your skills folder yourself.

In this catalog

Source file: skills/old-coder-api/SKILL.md in AmazingAng/old-coder
Installs to: ~/.claude/skills/old-coder-api
Collection: One of 2 skills cataloged from this repository
Category: AI Engineering — 2451 skills

What Old Coder API does

Old Coder API helps design, change, and review HTTP/JSON API contracts, including endpoints, request and response shapes, auth, pagination, idempotency, versioning, and deprecations. Use it when adding or reviewing an HTTP endpoint or OpenAPI change.

Old Coder API is cataloged under AI Engineering on DirSkills. Old Coder API comes from a repository tagged agent-skills, ai-agents, ai-coding, claude-code and code-quality.

Documentation

README

Excerpt

old-coder-api

Inspired by Sean Goedecke, Everything I know about good API design (2025-08-24).

This skill covers HTTP/JSON contract and operability concerns. Its compatibility rules assume JSON consumers. For gRPC/protobuf, GraphQL, WebSockets, or another protocol, apply the transport-independent principles only alongside that protocol's own compatibility rules. This is not a substitute for a full application-security review.

Good APIs are boring. For the people who build them, an API is a product. For the people who use them, it is a tool in the way of something else. Every minute a consumer spends thinking about your API instead of their goal is waste. An interesting API is a bad API — or would be a better one if it were less interesting.

This is the opening of the README. Read the full README on GitHub.

Commands Old Coder API provides

Slash commands named in this skill’s SKILL.md, listed in the order they first appear.

/issues
/projects
/users
/index

Frequently asked about Old Coder API

What else does AmazingAng publish alongside Old Coder API?
Old Coder API is one of 2 skills that DirSkills catalogs from AmazingAng/old-coder, the repository it ships in. Its siblings there include Old Coder. Each one is a separate skill with its own page in this directory, installs the same way Old Coder API does, and is maintained by AmazingAng in that same repository. The rest of the collection is listed on the AmazingAng/old-coder page.
How does Old Coder API compare to other AI Engineering skills?
Old Coder API ranks #1810 by stars among the 2451 AI Engineering skills in this catalog. The most-starred ones next to it are Architecture Decision Records, AI-First Engineering and Agentic OS. DirSkills ranks by the star count of the repository each skill ships in, so that order reflects how popular those repositories are rather than any review of Old Coder API against them. Open each page to compare what they document and how they install.