Skip to content
BranchesTags

Repository files navigation

Galacta

Galacta

A native Go agent daemon with Jeff, its terminal CLI.

What It Is

Galacta is a self-contained Go implementation of a Claude agent loop that runs as a local HTTP daemon. Jeff is the interactive CLI that talks to it — spinners, box-drawn UI, tab completion, multiline input, and all.

No Node.js. No Bun. No V8. No subprocess. ~10–15 MB idle.

Quick Start

# Build and install
make install

# Start the daemon (requires ANTHROPIC_API_KEY)
galacta serve

# Start an interactive session (default command)
jeff

# One-shot message
jeff "explain this codebase"

# Resume last session
jeff --continue

# Explicit run with flags
jeff run --model claude-sonnet-4-20250514 --effort high

Install

# Build both binaries
make build

# Install to /usr/local/bin (may need sudo)
make install

# Or install to a custom path
make install INSTALL_DIR=~/.local/bin

# Uninstall
make uninstall

Architecture

┌──────────────────────────────────────────────────────────────┐
│                         Galacta Daemon                       │
│                                                              │
│  HTTP API ──► AgentLoop ──► Anthropic Client (SSE)          │
│                  │                                           │
│                  ▼                                           │
│             ToolCaller ──► [Bash, Read, Write, Edit, Glob,  │
│                             Grep, WebFetch, WebSearch,       │
│                             Agent, Skill, Task, Team, ...]   │
│                  │                                           │
│                  ▼                                           │
│          PermissionGate ──► EventStream (SSE → Jeff CLI)    │
│                                                              │
│  SessionDB (SQLite) ──► history, tokens, tasks, metadata    │
└──────────────────────────────────────────────────────────────┘

┌──────────────────────────────────────────────────────────────┐
│                          Jeff CLI                            │
│                                                              │
│  main.go      Entry point, flags, session CRUD, HTTP helpers│
│  ui.go        Spinner, box drawing, banner, colors          │
│  events.go    SSE streaming with spinner + styled output    │
│  commands.go  Readline, /slash commands, tab completion     │
└──────────────────────────────────────────────────────────────┘

Core Components

Component Responsibility
AgentLoop The tool_use → execute → tool_result → repeat cycle
Anthropic Client Streaming Claude API client (SSE, content block deltas, rate limit capture)
ToolCaller Dispatches tool calls; serial and concurrent execution
PermissionGate Intercepts tool calls requiring user confirmation
EventEmitter Structured SSE events to connected clients
SessionDB SQLite-backed session history, token tracking, tasks
Team Manager Multi-agent teams with messaging and task coordination

Jeff CLI

Jeff is the terminal interface to Galacta. Running jeff with no arguments starts an interactive session.

       ╱▔▔▔▔╲
      ╱      ╲
     ╱  ·  ·  ╲
    ╱    ▽▽    ╲
   ╱  ▔▔▔▔▔▔▔▔  ╲
  ▕              ▏
   ╲   ╱    ╲   ╱
    ╲ ╱  jeff ╲╱

Features:

  • Tab completion — type / + Tab to autocomplete slash commands (readline)
  • Spinner indicators — animated braille spinner during thinking and tool execution
  • Box-drawn tool output — tool inputs, outputs, and durations in styled boxes
  • Multiline input — type """ to enter/exit multiline mode
  • Styled permission prompts — double-line box for approval requests
  • Question UI — numbered options in a box for interactive questions
  • Rate limit usage — /usage shows 5-hour and weekly limit utilization with progress bars

Interactive Commands

Command Description
/session Show session info
/model [name] Show or change model
/permissions [mode] Show or change permission mode
/history Conversation history
/compact [N] Compact conversation (keep last N messages)
/clear Clear screen
/tasks List tasks with status icons
/skills List available skills
/cost Session token usage and estimated cost
/usage Rate limit utilization (5h and weekly)
/plan Plan mode info
/help Show all commands
/quit End session

CLI Flags

jeff [flags] ["message"]
jeff run [flags] ["message"]

  --session, -s        Resume session by UUID
  --model, -m          Model override
  --dir, -d            Working directory (default: cwd)
  --mode               Permission mode
  --continue           Resume most recent session
  --output-format      stream | json | text
  --effort             low | medium | high
  --max-budget-usd     Spending cap in USD
  --tools              Tool allow list (repeatable)
  --allowedTools       Tool glob patterns (repeatable)
  --fallback-model     Fallback model on overload
  --galacta            Daemon URL (default: http://localhost:9090)
  --system-prompt      Override/append system prompt

Tools

File System

Tool Description
galacta_read Read file with optional line offset/limit
galacta_write Create or overwrite file
galacta_edit Exact string replacement
galacta_glob File pattern matching
galacta_grep Regex search with context lines
galacta_ls Directory listing

Execution

Tool Description
galacta_bash Shell execution with timeout and cancellation

Web

Tool Description
galacta_web_fetch HTTP fetch with HTML-to-markdown
galacta_web_search Web search (Anthropic server tool)

Agent & Orchestration

Tool Description
galacta_agent Spawn sub-agents for parallel work
galacta_skill Execute named skills (built-in or user-defined)
galacta_register_skill Create new skill files at runtime
galacta_task_* Task creation, listing, and updates
galacta_team_* Team creation, messaging, and coordination
galacta_ask_user Interactive questions with options
galacta_enter_plan_mode Enter plan mode for implementation planning
galacta_worktree Git worktree isolation

MCP (Dynamic)

External MCP tools are registered at runtime as mcp__{server}__{tool} based on connected MCP servers.

Permission Modes

Mode Behavior
default Ask before bash commands and writes outside cwd
acceptEdits Auto-approve file edits; ask before bash
bypassPermissions No prompts — execute everything
plan Read-only; no writes or bash
dontAsk Auto-approve everything

Skills

Skills are reusable prompt templates loaded from multiple sources:

Source Path Format
Built-in hardcoded commit, review-pr
Global skills ~/.claude/skills/{name}/SKILL.md Frontmatter + prompt
Global commands ~/.claude/commands/{name}.md First line = description, rest = prompt
Installed plugins ~/.claude/plugins/cache/.../skills/{name}/SKILL.md Frontmatter + prompt
Project skills {cwd}/.claude/skills/{name}.md Frontmatter + prompt
Runtime via galacta_register_skill tool Agent creates skills on the fly

Skill file format:

---
name: my-skill
description: Does something useful
---
Your prompt template here. Use {{.Args}} for arguments.

List skills with /skills in Jeff or GET /skills.

API

Galacta exposes an HTTP API on port 9090 (default).

Method Endpoint Description
GET /health Daemon status
POST /sessions Create session
GET /sessions List sessions
GET /sessions/{id} Get session info
PATCH /sessions/{id} Update session (model, mode)
DELETE /sessions/{id} Delete session
POST /sessions/{id}/message Send message (SSE stream)
GET /sessions/{id}/messages List message history
POST /sessions/{id}/compact Compact conversation
GET /sessions/{id}/tasks List tasks
POST /sessions/{id}/permission/{rid} Respond to permission
POST /sessions/{id}/question/{rid} Respond to question
GET /skills?working_dir=... List available skills
GET /usage Rate limit utilization

SSE Event Types

{ "type": "text_delta", "text": "..." }
{ "type": "thinking_delta", "text": "..." }
{ "type": "tool_start", "tool": "galacta_bash", "input": { "command": "ls" } }
{ "type": "tool_result", "tool": "galacta_bash", "output": "...", "duration_ms": 23 }
{ "type": "permission_request", "request_id": "...", "tool": "...", "input": { ... } }
{ "type": "question_request", "request_id": "...", "question": "...", "options": [...] }
{ "type": "usage", "input_tokens": 1234, "output_tokens": 456 }
{ "type": "turn_complete", "stop_reason": "end_turn" }
{ "type": "plan_mode_changed", "active": true }
{ "type": "subagent_start", "agent_type": "general-purpose", "description": "..." }
{ "type": "team_created", "team_name": "..." }
{ "type": "team_message", "from": "...", "recipient": "...", "summary": "..." }
{ "type": "error", "message": "..." }

Non-Goals

  • Terminal UI / TUI rendering (Jeff is intentionally simple ANSI)
  • Claude Code CLI compatibility mode
  • Multi-user / networked deployment
  • Sandboxed bash execution

About

Galacta & Jeff, Go-based Claude Code Clone

Resources

Readme
Activity

Stars

1 star

Watchers

0 watching

Forks

0 forks
Report repository

Releases

Packages

Contributors

Languages