# vercel-labs/fx

Unix like coding agent

Repository: https://github.com/vercel-labs/fx
Canonical: https://ross.abutalabs.com/products/vercel-labs-fx
Homepage: https://fx.sh
Language: Zig
License: Apache-2.0
License Family: permissive
Last push: 2026-08-26T21:36:21+00:00

## Health v2 (maintenance only)
Score: 79/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 99, longevity 1
- inputs: {"age_days": 22, "days_push": 7, "days_rel": 9, "gap_med": 1, "n_releases_24m": 6}
- flags: young
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2495, forks 266 (observed 2026-08-28T04:06:55.401506+00:00)

## What it is
fx is a tiny, open-source coding agent harness and CLI written in Zig, designed for minimalism, fast cold starts, and embeddability in larger systems. It offers a Unix shell-like terminal experience, model-agnostic inference via Vercel AI Gateway, OpenAI Codex, or xAI Grok, and embeds into JavaScript apps via libfx (native addon and WebAssembly builds).

## Use cases
- run an AI coding agent in the terminal
- embed a coding agent into my own application
- add an agent runtime to an editor via ACP
- run a coding agent in the browser with WebAssembly
- automatically draft pull requests and issues from a repo
- use my ChatGPT or Grok subscription for AI coding assistance
- run a lightweight agent in resource-constrained sandboxes

## When to choose
- you want a minimal, fast, low-memory coding agent CLI
- you need to embed an agent runtime in Node or browser apps
- you prefer a shell-like terminal experience over heavy TUI IDEs
- you want model-agnostic access across multiple providers and MCP servers

## When to avoid
- you need a stable, production-hardened tool - it is explicitly experimental
- you want a rich IDE-like TUI with extensive visual features
- you need Windows support - only macOS and Linux are supported

## Facets
- artifact type: cli-tool
- maturity: experimental
- function: agent-framework, cli, llm-inference, mcp, developer-tools
- domain: developer-tools, artificial-intelligence
- platform: cli, wasm, browser
- tags: coding-agent, agent-harness, zig, acp, embeddable, model-agnostic, terminal-ui, wasm, command-line, ai-agents, macos, linux, nodejs

## Member repositories
- vercel-labs/fx (main) score 79

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:55.401506+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:27:14.381164+00:00, confidence not recorded.
  - readme: https://github.com/vercel-labs/fx (fetched 2026-08-28T04:06:55.401506+00:00, sha 47dca8e9271a)
  - homepage: https://fx.sh (fetched 2026-08-29T10:09:30.886403+00:00, sha 3014c2a7c692)
  - site_page: https://fx.sh/docs/using-fx/cli (fetched 2026-08-29T10:09:30.897232+00:00, sha 2cfa3e71e0b4)
  - site_page: https://fx.sh/docs (fetched 2026-08-29T10:09:30.895319+00:00, sha 9116e92ce9b2)
  - site_page: https://fx.sh/docs/lib (fetched 2026-08-29T10:09:30.899045+00:00, sha 53373b2ca204)
  - site_page: https://fx.sh/docs/lib/host-integration (fetched 2026-08-29T10:09:30.902853+00:00, sha cf1c2a54e4d3)
  - site_page: https://fx.sh/docs/getting-started/installation (fetched 2026-08-29T10:09:30.904904+00:00, sha 844a0d9896a6)
  - site_page: https://fx.sh/changelog (fetched 2026-08-29T10:09:30.900700+00:00, sha 8aab74d19bb4)
- Data as of 2026-08-30T08:39:29.467469+00:00.