ADE vs fx: Features, Pricing & Which Is Better (2026)

A side-by-side comparison of ADE and fx — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.

ADE

Free

An open-source agentic development environment that runs every major AI coding agent, synced across web, desktop, terminal, and mobile.

Multi-Agent Support: Runs Claude Code, Codex, Cursor, Factory Droid, and OpenCode inside one workspace so developers do not switch UIs.
Cross-Surface Sync: Web, desktop, terminal, and mobile clients share the same chat history and state in real time.
Per-Task Git Worktrees: Every task spins up its own worktree so parallel agents ship features without merge collisions.
In-App PR Review: Review, edit, and merge pull requests generated by agents without leaving ADE.
Bring Your Own Subscription: Reuses whichever coding-agent subscriptions the developer already pays for.
Open Source Core: AGPL-licensed and free to run locally, with full source available on GitHub.
Mobile Continuation: Kick off a feature on desktop and steer or approve it from the phone with identical context.

Agent Fleet Coordination: Run several coding agents in parallel on different features without merge conflicts.
Cross-Device Development: Start a coding task on a laptop and continue it seamlessly from mobile while traveling.
PR Triage: Review, comment on, and merge agent-generated PRs in-app instead of jumping to GitHub.
Consolidated Tooling: Replace several standalone AI-coding UIs with one workspace that speaks to all of them.
Self-Hosted Dev Environment: Teams that need code isolation run the open-source ADE stack on their own hardware.

Vercel Labs

Free

Vercel Labs' tiny open-source coding agent — a ~6 MB native CLI written in Zig, built for speed, embeddability and Unix-style ergonomics.

Tiny Native Binary: The whole agent ships as a roughly 6 MB executable designed for instant installation and for embedding in resource-constrained environments and agent sandboxes.
Instant Time to Prompt: fx cold starts in about 10 microseconds and performs no unnecessary work or I/O before accepting user input, which matters for programmatic invocation.
Minimal Memory Footprint: A single-digit-megabyte memory baseline lets you pack many concurrent instances onto one machine.
Shell-Like Ergonomics: Scroll history is preserved by default and output is deliberately sparse, so the CLI composes like a Unix tool instead of taking over the terminal.
Context Efficiency: A minimal system prompt and tool surface reduce token spend and improve time-to-first-token performance.
WebAssembly Builds: Optimal fx.wasm builds from the Zig toolchain shrink the binary further and make the network stack pluggable, enabling the in-browser demo.
Model and Provider Agnostic: Works with local models, LLM gateways, direct provider API access or existing subscriptions rather than locking you to one vendor.
Extensible Small Core: Capabilities are added through skills, plugins and MCPs, following a Unix-like philosophy of a small core with composable extensions.

Sandboxed Agent Execution: Ship a full coding agent inside a container or sandbox where a large runtime would not fit.
Embedding in Larger Systems: Use fx as the agent harness inside your own product or internal platform rather than building a loop from scratch.
CI and Scripted Automation: Invoke a coding agent from pipelines and scripts where fast cold starts and quiet output matter more than an interactive UI.
Agent Harness Research: Experiment with system prompt and tool design on a deliberately minimal, readable Apache-2.0 codebase.
Local-Model Coding: Run agentic coding against a locally hosted model without any dependency on a specific cloud provider.
Browser-Based Demos and Playgrounds: Compile to WebAssembly and run the agent client-side with networking delegated to browser fetch.