The Agentic Web
You direct. It creates.
You're in control the whole time.
Live in your browser, real tool calls.
You say what you want. It builds it live, call by call, right in front of you. 50 free tool calls to start. Buy credits to keep going.
Say "lo-fi jazz, C minor, slow." Watch notes land on the piano roll one by one. Instruments chosen, rhythm set, track built. Push back, redirect, ask for more.
Say "hard, lots of gaps, underwater theme." Platforms drop, enemies appear, coins scatter. A unique playable level from your description. Play it the moment it's done.
Say "microservices diagram, three services, one database." Shapes appear, arrows connect, labels land directly on a live canvas. Edit anything the moment it's done.
Say "geometric logo, purple and gold, diamond shape." Paths form, shapes fill, elements group. Your idea built as vector art, call by call, right in front of you.
Every tool call hits a real LLM. Credits cover that compute. Here's exactly how it works — no surprises.
Every new visitor starts free — enough to compose a track, play a level, or draw a diagram. No account. See the magic first.
When free calls run out, buy credits at app.leanmcp.com. Covers LLM routing — same cost as going direct plus ~0.5% gateway fee.
Same credits work across all four demos and the LeanMCP AI Gateway — use them to monitor your Cursor, Cline, or OpenClaw too.
What a session costs: One Music Composer session (3–4 tracks) ≈ 40–60 tool calls ≈ $0.08–$0.15. A Mario level ≈ 20–30 calls ≈ $0.04–$0.08. You're paying for AI compute, not the demo.
Most browser AI takes screenshots and clicks pixels. WebMCP is different — websites register JavaScript functions, agents call them directly.
The agent screenshots the page, infers where the piano key is, sends a click at pixel (324, 180), waits for the DOM, screenshots again to verify. 10× tokens. Breaks every UI change.
Page registers add_note({ pitch:"C4", duration:0.5 }) via navigator.modelContext.registerTool(). Agent calls it. Instant, validated, never breaks. 10× cheaper.
Three types of people land here. Pick your path.
You want to keep going. Buy credits at app.leanmcp.com. Same credits work across all four demos. 2 minutes.
Get credits →You want AI agents calling your own product's tools directly. LeanMCP SDK handles deployment, auth, rate limiting, and observability.
Read the AI Gateway docs →You have a product. You want this but not 6 weeks of infra work. Auth, observability, deployment. Fixed price, done for you.
See Production Sprint →These demos run on LeanMCP's production infrastructure. The same platform is available for your own agents and tools.
Running Cursor, Cline, or OpenClaw? The same gateway routing these demos sits between your agents and every LLM. One URL change. Full visibility.
Working prototype. Auth half-built. Logging is console.log. You want WebMCP tools on your product without 6 weeks of infra work. We do it in 2 weeks.
Three paths. All start at app.leanmcp.com.