Mini-Code

A mini version of Claude Code. A terminal-based AI agent application that enables conversational interaction with Claude through a Text User Interface (TUI).

Features

• Interactive terminal UI for chatting with Claude
• Built-in tools: read files, list directories, grep search
• Real-time streaming responses via Server-Sent Events
• Conversational interaction with Claude through a Text User Interface (TUI)
• Built-in tools: read files, list directories, grep search
• Real-time streaming responses via Server-Sent Events
• Markdown rendering in the terminal
• Conversation and prompt history
• Configurable logging for debugging
• Conversation and prompt history
• Configurable logging for debugging

Requirements

• Go 1.23+
• Bun (JavaScript runtime)
• Anthropic API key

Installation

# Clone the repository
git clone https://github.com/user/harness.git
cd harness

# Install all dependencies
make deps

Quick Start

1. Set your API key:

export ANTHROPIC_API_KEY=sk-ant-...

2. Run the backend (terminal 1):

make run-backend

3. Run the TUI (terminal 2):

make run-tui

Usage

Make Commands

make help           # Show all available commands

# Build
make build          # Build both backend and TUI
make build-backend  # Build Go backend only
make build-tui      # Build TUI only

# Run
make run-backend    # Build and run the backend server
make run-tui        # Build and run the TUI
make dev-backend    # Run backend with go run (no build step)
make dev-tui        # Build and run TUI in one step

# Test
make test           # Run all tests
make test-verbose   # Run tests with verbose output
make test-coverage  # Generate coverage report
make test-e2e       # Run end-to-end tests

# Code Quality
make fmt            # Format Go code
make vet            # Run go vet
make typecheck      # TypeScript type checking
make check          # Run all checks

# Clean
make clean          # Remove build artifacts
make clean-all      # Remove everything including node_modules

Environment Variables

Variable	Description	Default
ANTHROPIC_API_KEY	Required. Anthropic API key	—
HARNESS_ADDR	Server listen address	:8080
HARNESS_MODEL	Claude model ID	claude-3-haiku-20240307
HARNESS_SYSTEM_PROMPT	Custom system prompt	empty

Logging Configuration

Variable	Description	Default
HARNESS_LOG_LEVEL	DEBUG, INFO, WARN, ERROR	INFO
HARNESS_LOG_FORMAT	text or json	text
HARNESS_LOG_CATEGORIES	http,sse,api,tool,harness	all
HARNESS_AGENT_LOG	File path for agent interaction logs	disabled
HARNESS_AGENT_LOG_FORMAT	text or json	text

Example Configurations

# Basic usage
ANTHROPIC_API_KEY=sk-ant-... make run-backend

# Debug mode
ANTHROPIC_API_KEY=sk-ant-... HARNESS_LOG_LEVEL=DEBUG make run-backend

# With agent logging
ANTHROPIC_API_KEY=sk-ant-... \
HARNESS_AGENT_LOG=~/.harness/agent.log \
make run-backend

# Production (JSON logs)
ANTHROPIC_API_KEY=sk-ant-... \
HARNESS_LOG_FORMAT=json \
HARNESS_AGENT_LOG=/var/log/harness/agent.log \
HARNESS_AGENT_LOG_FORMAT=json \
make run-backend

Project Structure

harness/
├── cmd/harness/          # Go server entry point
├── pkg/
│   ├── harness/          # Core agent harness logic
│   ├── server/           # HTTP/SSE server
│   ├── log/              # Logging system
│   ├── tool/             # Tool implementations (read, list_dir, grep)
│   └── testutil/         # Test utilities
├── tui/                  # TypeScript TUI (Solid.js + OpenTUI)
│   ├── src/
│   │   ├── components/   # UI components
│   │   ├── stores/       # Reactive state
│   │   ├── lib/          # Utilities
│   │   └── schemas/      # Zod validation
│   └── dist/             # Build output
├── tests/e2e/            # End-to-end tests
├── specs/                # Specifications
├── Makefile              # Build commands
└── README.md             # This file

Available Tools

The AI agent has access to three tools:

Tool	Description
read	Read file contents
list_dir	List directory contents
grep	Search files with regex patterns

TUI Keybindings

• Enter - Submit prompt
• Up/Down - Navigate prompt history
• Ctrl+C - Cancel current operation / Exit
• ? - Show help overlay

License

MIT