Claude Coding Agent — Development skill for Claude Code

Simple Coding Agent (TypeScript)

A small, easy-to-read coding agent, similar in spirit to tools like Pi: you type a request, Claude figures out which tools it needs, and the agent runs them (reading/writing files, running commands) until the task is done.

No frameworks, no hidden magic - just a loop and five tools.

Folder structure

coding-agent/
├── src/
│   ├── main.ts          # CLI entry point
│   ├── agent.ts          # The agent loop (talks to Claude, runs tools)
│   ├── tools.ts            # Tool definitions + implementations
│   └── config.ts           # Settings (API key, model, limits)
├── package.json
├── tsconfig.json
└── .env.example

How it works

1. src/main.ts starts a chat loop and creates an Agent.
2. Each time you type something, agent.run() sends the conversation to Claude along with the list of available tools (src/tools.ts).
3. If Claude wants to use a tool (e.g. read_file), the agent runs the matching function locally and sends the result back to Claude.
4. This repeats until Claude responds with a plain text answer and no more tool calls - then control returns to you.

Available tools

Tool	What it does
read_file	Read a file's contents (with line numbers)
write_file	Create or overwrite a file
edit_file	Find-and-replace a unique snippet of text in a file
list_directory	List files/folders in a directory
run_command	Run a shell command (e.g. run tests, install packages)

All file/command tools are restricted to `AGENT_WORKING_DIR` (default: the current folder) so the agent can't wander outside your project.

Setup

1. Install dependencies:

   npm install

2. Copy `.env.example` to `.env` and add your API key:

   cp .env.example .env
   # then edit .env and s