Open-source terminal agent

Minimal overhead.
Maximum agent.

One native binary. Your choice of model. Shape agent behavior and coordinate work across agents, with control at every step.

Start with San

brew install genai-io/san/san

macOS, Linux & Windows · Apache 2.0
Releases and downloads

A quick introduction

Meet San in 70 seconds.

From choosing a model to working across agents. The original comic tour, at your pace. Model names and limits are illustrative; performance figures are version-specific.

San — a lightweight, open-source terminal agent
Why San

Less framework. More room to work.

Lightweight by design, adaptable to your workflow. The essentials for capable agents, without prescribing how you use them.

01Lightweight

Small footprint. Fast start.

One native Go binary, no Node.js or Python runtime. A ~12 MB download and ~2.3k tokens of harness context leave more resources for your task.

See measurements and versions →

02Your harness

Your model. Your way of working.

A model-agnostic runtime with configurable system prompts, personas, skills, and tools. Shape agent behavior without adopting someone else's workflow.

Compose the system prompt →

03Collaboration

One task. More than one agent.

Delegate to subagents, exchange messages across sessions, and assemble dynamic workflows. Split the work without losing the thread.

/group
04Control & inspection

Decide what runs. See what happened.

Configure execution permissions and inspect model context and tool calls. Set the agent's scope, then review the run rather than guessing.

Shift+Tabsan inspector

All features · Architecture

Benchmark

A smaller runtime, measured.

Against Claude Code on Apple Silicon, with the same model (claude-sonnet-4-6) and tasks. Results are specific to the versions below.

MetricSanClaude CodeComparison
Download size12 MB63 MB + Node 112 MB5× smaller¹
Disk footprint38 MB175 MB4.6× smaller
Startup time (version)~0.01s~0.20s20× faster
Startup memory~32 MB~189 MB5.8× less
Simple task~2.4s / 39 MB~10.4s / 286 MB4.3× faster
Tool-use task~3.3s / 39 MB~26.0s / 285 MB7.9× faster
Harness context²~2.3k tokens~20.9k tokens~9× leaner

Task figures are wall time / peak RSS in print mode; network and API latency vary. Startup measures the version command, not time to an interactive prompt. ¹ Download comparison excludes the additional Node runtime. ² Harness context is system prompt + tool schemas on an empty first turn, measured separately on San v1.22.0 vs Claude Code v2.1.220. All other rows are from the San v1.13.2 / Claude Code v2.1.112 run. Method and reproduction →

Community

Build with us.

Share workflows, ask questions, and help shape San.

WeChat

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