GitHub - vercel-labs/fx: Unix like coding agent · GitHub
/" data-turbo-transient="true" />
Skip to content
Search/
Sign in<br>Sign upAppearance settings
You signed in with another tab or window. Reload to refresh your session.<br>You signed out in another tab or window. Reload to refresh your session.<br>You switched accounts on another tab or window. Reload to refresh your session.
Dismiss alert
{{ message }}
Uh oh!
There was an error while loading. Please reload this page.
vercel-labs
fx
Public
Notifications<br>You must be signed in to change notification settings
Fork
Star<br>62
main
BranchesTags
Go to file
CodeOpen more actions menu
Latest commit
History<br>340 Commits<br>340 Commits
Folders and files<br>NameNameLast commit message<br>Last commit date<br>.github
.github
benchmarks
benchmarks
scripts
scripts
sdk
sdk
src
src
tests
tests
.gitignore
.gitignore
AGENTS.md
AGENTS.md
CHANGELOG.md
CHANGELOG.md
CONTRIBUTING.md
CONTRIBUTING.md
LICENSE
LICENSE
README.md
README.md
THIRD_PARTY_NOTICES.md
THIRD_PARTY_NOTICES.md
build.zig
build.zig
build.zig.zon
build.zig.zon
View all files
Repository files navigation
⠀⠀⠀⠀⠀⠀⣠⣾⣿⣿⣿⠀⠀⠀⠀⠀⠀⠀⠀<br>⠀⠀⠀⠀⠀⢰⣿⡿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀<br>⠀⠀⠀⣠⣶⣿⣿⣷⣶⡶⣶⣶⣆⠀⠀⠀⣴⣶⣶⠆<br>⠀⠀⠀⠉⢹⣿⣿⠉⠉⠀⠘⢿⣿⣧⣀⣾⣿⡿⠃⠀ Tiny, open, embeddable, native coding agent.<br>⠀⠀⠀⠀⣼⣿⡏⠀⠀⠀⠀⠀⠻⣿⣿⣿⠟⠀⠀⠀<br>⠀⠀⠀⢀⣿⣿⠃⠀⠀⠀⠀⢠⣦⠘⢿⣿⣷⡀⠀⠀ curl -fsSL https://fx.sh/setup.sh | bash<br>⠀⠀⠀⣸⣿⡟⠀⠀⠀⠀⣰⣿⣿⠗⠀⠻⣿⣿⣄⠀<br>⠀⠀⠀⣿⣿⠇⠀⠀⠀⠾⠿⠿⠋⠀⠀⠀⠘⠿⠿⠦ ⚠ Status: Experimental. Use at your own risk.<br>⠀⣸⣿⡿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀<br>⣿⣿⣿⠟⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
fx is a coding agent harness and CLI written in Zig, optimized for research and embeddability as part of larger systems.
It focuses on minimalism and performance across the board, from system prompt design to its tools, feature set, and 7.8 MiB binary.
For end users, its CLI output style and form factor aim to be closer to a Unix shell than a heavy "IDE in the terminal" TUI.
It's open source (Apache-2.0), model-agnostic, and suitable for both local and cloud inference.
Install
curl -fsSL https://fx.sh/setup.sh | bash
Run fx
To get started, sign in with Vercel:
fx login
Or add an AI Gateway API key:
fx setup
Run fx from a project:
cd your_project<br>fx
The current directory becomes the primary workspace. Enter a prompt, or run /help to browse interactive commands.
Run /feedback to open the feedback form at fx.sh/feedback. It does not create a diagnostic or change the clipboard.
Run /trace to create a private Markdown diagnostic with logs, session context, runtime state, permissions, and recent activity. On macOS, fx copies the .md file to the clipboard; on other platforms, it saves the file and prints its path. Review and redact the trace before sharing it.
Use fx ask for a single request:
fx ask "explain the changes in this repository"
fx starts in auto permission mode, which reviews unresolved sensitive actions. See Permissions for other modes and persistent rules.
Inside a saved session, /permissions remember stores an exact confirmed rule without running the action. /permissions lists stable rule IDs, and /permissions revoke removes a stored rule even when its original workspace or file state has changed.
Embed fx
fx builds as a native binary or WebAssembly. Applications embedding fx can provide network transport, session storage, configuration, permission handling, and terminal I/O.
Surface<br>Use
fx acp<br>Connect the native agent to editors and other Agent Client Protocol clients.
createFxAgent()<br>Embed the agent core in a JavaScript host with fx-core.wasm.
createFxTerminal()<br>Embed the interactive terminal with fx-term.wasm.
The WebAssembly SDK is experimental. See the WebAssembly SDK and ACP documentation.
Extend fx
Add reusable instructions with skills, connect external tools through MCP, or delegate independent work to subagents. Project instruction files may link within their scope, and read-only workspace or compatibility skill directories may link within their owning workspace or home; managed skills, SKILL.md files, resources, and escaping links remain no-follow. fx status and fx doctor report an invalid trusted MCP profile without starting its servers.
Documentation
Read the fx documentation.
Build from source
Building fx requires Zig 0.16.0+:
git clone https://github.com/vercel-labs/fx.git<br>cd fx<br>zig build -Doptimize=ReleaseSafe<br>./zig-out/bin/fx
Run the test suite with zig build test. See CONTRIBUTING.md for development and contribution guidelines.
License
Apache-2.0
Third-party licenses and attributions are listed in<br>THIRD_PARTY_NOTICES.md.
Credits
Interface sounds by cuelume.
About<br>Unix like coding agent<br>fx.sh<br>Resources<br>Readme<br>Apache-2.0 license<br>Contributing<br>Contributing<br>Activity<br>Custom properties<br>Stars<br>62 stars<br>Watchers<br>0 watching<br>Forks<br>2 forks<br>Report repository
Releases
Used by
Contributors
Languages
You can’t perform that action at this time.