⚡ FastCode

A colorful, fast, terminal-first AI coding assistant.

Multi-LLM chat • Agent Skills • Slash commands • Themes • Termux-ready

npm install -g @simplelittledev/fastcode
fastcode

Short alias included:

fc

🌈 What Is FastCode?

FastCode is a beautiful TUI coding assistant that runs inside your terminal. It connects to your favorite AI provider, keeps the workflow command-driven, and supports Anthropic-style Agent Skills for specialized abilities.

It is built for developers who want an AI assistant that feels quick, direct, and usable from anywhere: Linux, macOS, Windows, and Android through Termux.

✨ Highlights

🚀 Install

Global install

npm install -g @simplelittledev/fastcode
fastcode

Run without installing globally

npx @simplelittledev/fastcode

Start with a prompt

fastcode "explain this repository"

🔑 Add Your API Key

Use environment variables:

export ANTHROPIC_API_KEY="sk-ant-..."
export OPENAI_API_KEY="sk-..."
export OPENROUTER_API_KEY="sk-or-..."

Or save a key from inside FastCode:

/login openai sk-...
/login anthropic sk-ant-...

Then start chatting:

fastcode

🧩 Providers

Switch anytime:

/provider openai
/model gpt-4o-mini

🪄 Agent Skills

FastCode can install and inject Anthropic-style skills into the system prompt.

/skills search pdf
/skills install pdf
/skills install anthropics/skills/pdf
/skills install https://example.com/my-skill/SKILL.md
/skills enable pdf
/skills list
/skills info pdf

Installed skills live here:

~/.fastcode/skills/<name>/SKILL.md

🛠️ Coding Agent

FastCode can act as a local coding agent. Agent mode is enabled by default and works with any provider, including local Ollama models.

/agent status
/agent on
/agent off
/tools
/cwd

Available tools include:

shell, pwd, read_file, read_many, write_file, append_file, apply_patch,
replace_in_file, list_files, grep, stat_path, make_dir, copy_file,
move_path, delete_file

Tools run inside a sandbox rooted at the directory where you start FastCode. File tools cannot access paths outside that root. Shell commands run with:

FASTCODE_SANDBOX=1
FASTCODE_SANDBOX_ROOT=<current-working-directory>

Example:

cd ~/my-project
fastcode "run the tests, find the failing file, patch it, and verify the fix"

🧩 Plugins

Plugins are always-active behavior packs. A plugin folder can contain:

my-plugin/
├── PLUGIN.md
└── skills/
    └── reviewer/
        └── SKILL.md

Import and enable a plugin:

/plugin import ./my-plugin reviewer
/plugin list
/plugin info reviewer
/plugin disable reviewer
/plugin enable reviewer
/plugin remove reviewer

Installed plugins live under:

~/.fastcode/plugins/

🎮 Slash Commands

Keyboard controls:

Esc       cancel streaming
Ctrl+C    press twice to quit

🎨 Themes

/theme fastcode
/theme neon
/theme sunset
/theme matrix
/theme mono

Want the calmest terminal experience?

FASTCODE_STABLE_UI=1 fastcode

Termux enables stable UI automatically.

📱 Termux

Install Node.js first:

pkg install nodejs
npm install -g @simplelittledev/fastcode
fastcode

If the command is not found, check your npm global binary path:

npm bin -g
echo "$PATH"

FastCode stores config inside your home directory:

~/.fastcode/
├── config.json
├── auth.json
├── skills/
├── plugins/
├── cache/
├── sessions/
└── logs/

You can move that root with:

FASTCODE_HOME=/path/to/fastcode fastcode

🛠️ Development

git clone https://github.com/SimpleLittleDev/FastCode
cd FastCode
npm install
npm run dev

Quality checks:

npm run check

Or run each step:

npm test
npm run typecheck
npm run lint
npm run build

Run the built CLI:

node ./bin/fastcode.mjs

📦 Publish Notes

The package exposes two global commands:

{
  "bin": {
    "fastcode": "./bin/fastcode.mjs",
    "fc": "./bin/fastcode.mjs"
  }
}

Publish public scoped releases with:

npm publish --access public

📜 License

MIT © SimpleLittleDev