Zerostack – Tiny Rust Coding Agent in 8MB of RAM
Zerostack is a minimal coding agent developed in Rust, designed to operate efficiently with a small RAM footprint. It supports multiple providers and features a variety of tools for coding tasks, including a permission system and session management. With a binary size of 8.9MB and low CPU usage, Zerostack aims to be one of the most performant coding agents available.
- ▪Zerostack has a RAM footprint of approximately 8MB on an empty session and 12MB when in use.
- ▪The coding agent supports multiple providers, including OpenRouter and OpenAI, and features a terminal UI with markdown rendering.
- ▪It includes a built-in prompts system that allows users to switch between different modes tailored to specific tasks.
Opening excerpt (first ~120 words) tap to expand
zerostack Minimal coding agent written in Rust, inspired by pi and opencode. Features Multi-provider: OpenRouter, OpenAI, Anthropic, Gemini, Ollama, plus custom providers Standard tools: all of the standard tools exposed to coding agents, as described by the opencode documentation. Permission system: four configurable modes with per-tool patterns, session allowlists, and external directory policies Session management: save/load/resume sessions, auto-compaction to stay within context windows Terminal UI: crossterm-based, markdown rendering, mouse selection/copy, scrollback, reasoning visibility toggle Prompts system: switch between system prompt modes at runtime (code, plan, review, debug, etc.) to tailor the agent's behavior to the task without having to manage Skills.
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Excerpt limited to ~120 words for fair-use compliance. The full article is at GitHub.