Σ sigma

· coding agent

A coding-agent CLI in Go. It reuses your Claude Code subscription credentials, so no API key is needed.

Sigma is a minimal but complete agent harness with the Claude-standard feature set — tools, a permission gate, rules, slash commands, skills, MCP servers, hooks, sub-agents, and resumable sessions.

Install

go build -o sigma ./cmd/sigma

Requires Go 1.25+ and an authenticated Claude Code install.

Use

sigma run "Summarize the TODOs in this repo."
sigma chat            # interactive TUI; /help lists commands

What's inside

• Tools — read, write, edit, bash, glob, grep
• Permission gate — read-only tools auto-run; mutating tools prompt
• Rules — CLAUDE.md injected into the system prompt
• Slash commands & skills — templated commands, progressive-disclosure skills
• MCP — stdio + streamable-http servers
• Hooks — PreToolUse / PostToolUse shell commands
• Sub-agents — delegate a subtask to a fresh agent
• Sessions — autosaved and resumable

More docs land as features ship.