fx (by Vercel) is Vercel's tiny, open-source coding agent Open-source coding agent developed and maintained by Vercel.
About fx (by Vercel)
fx is an AI coding agent built and maintained by Vercel that runs as a small, open-source tool for software development work.
Its standout trait is being distributed as open-source software under Vercel's stewardship, paired with a deliberately tiny footprint meant to keep resource demands low compared to heavier agent frameworks.
It fits developers who prefer open-source tooling they can adapt themselves, and anyone who wants a coding agent without the bloat of heavier alternatives.
Within the AI coding agents category, fx competes on openness and minimalism rather than on a wide range of features or integrations.
Sources: the tool's official site, this listing
What it does well
- Open-source coding agent developed and maintained by Vercel.
- Designed as a lightweight 'tiny' agent with minimal footprint.
Tagged
- Web-based
- Agentic Mode
- Free
- Open Source
Compared with similar things
Picked by shared tags inside the AI Coding Agents.
- 01Freemium →n8n
Open-source workflow automation with native LLM nodes — self-host on your own infrastructure.
- 02Freemium →Convex
Reactive backend platform with AI agents and Chef — a no-code app builder built on Convex.
- 03Freemium →AgentGPT
Web-based autonomous agent — give it a goal, watch it self-plan and execute with web browsing and code.
- 04Freemium →Skyvern
LLM-powered browser automation that handles forms, captchas, and multi-page flows reliably.
- 05→HarnessRouter Community Edition
Open-source unified interface for agent harnesses
- 06→Unsloth Desktop
Run and train AI models locally on your desktop
Related reading
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Read guide → - The Best Vibe Coding Tools
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Read guide → - How to Build an MVP with AI
You don't start by building. You start by finding the one assumption that would kill the idea, then build the smallest thing that tests it. Here's the full idea-to-deployed workflow from a live AI build session: research the market with ChatGPT, pick a segment on unit economics, have AI write the PRD, then vibe-code and ship with Claude Code — in a couple of hours, not a quarter.
Read guide →
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</a>Frequently asked questions
- What is fx (by Vercel)?
- fx (by Vercel) is Vercel's tiny, open-source coding agent
- What category does fx (by Vercel) belong to?
- fx (by Vercel) is in the AI Coding Agents category — Autonomous agents that write, edit, run, and review code. Includes CLI agents, agentic IDE add-ons, and code-review bots.