Skip to content
mcpfy
Open Cloud

open source

The fullstack MCP framework

One open-source SDK for TypeScript and Python: build MCP Apps for ChatGPT and Claude, MCP Servers for agents, and the clients that talk to them — with typed tools and native views.

Read the docsView on GitHub

Our open source tools are used by developers at top companies

NorthwindApertureCogentLumenBrightpathSundialMeridianIroncladBlue HarborKestrel

How it runs

Everything the protocol needs, in one package

  1. 1

    Scaffold

    One command to a working server.

  2. 2

    Define

    Typed tools, resources and prompts.

  3. 3

    Bind

    Attach views directly to tools.

  4. 4

    Test

    Inspector and evals built in.

Typed tools

Schemas are the contract with the model. Define them once and get validation, docs and client types for free.

acme-mcp — zsh

➜ npx create-mcpfy-app

✓ tools/chart-sales.ts

✓ widgets/Chart.tsx

✓ mcpfy.config.ts

➜ mcpfy dev

ready on :4141 · 6 tools registered

tools/chart-sales.ts

export const chartSales = tool({
  name: "chart_sales",
  input: z.object({ period: z.string() }),
});

Native views

Bind a component straight to a tool and it renders inside the host client, with full state.

Cloud Inspectorsession #4f2a

San Francisco, CA

72°F

Partly cloudy · H 74° L 58°

now72°
2pm74°
3pm73°
4pm70°
5pm66°
6pm63°

→ tools/call

{
  "name": "display_weather",
  "arguments": { "city": "San Francisco" }
}

← result20041ms

{ "content": [{ "type": "resource" }] }

GPT-5.2

18/18

Claude

18/18

Gemini

17/18

Servers, clients and agents

The same package builds the server, the client that calls it, and an agent that orchestrates both.

Tool calls · 24h24,732

last 24h ↑ 12.4%

By country34 regions

Tracesp50 42ms

  • tools/call display_weatherclaude142ms
  • resources/listchatgpt18ms
  • tools/call search_docscursor842ms
  • prompts/listcopilot12ms
  • tools/call fetch_urlclaude503

p50

38ms

p95

112ms

errors

0.2%

In the box

TypeScript and Python, first class

1

Type-safe

End-to-end types from schema to client.

2

Framework friendly

Drop into Express, FastAPI or Hono.

3

MIT licensed

Open from day one, no lock-in.

4

Self-hostable

Run it anywhere, cloud optional.

Start building with the open SDK

Start deployingBook a call

Explore the rest of the platform

MCP Hosting

GitHub-native builds, preview URLs per branch, production endpoints with TLS and custom domains, and instant rollback — purpose-built for MCP traffic and the clients that connect to it.

Learn more

Cross-client testing

Your server behaves differently in ChatGPT than it does in Claude or Cursor.

Learn more

Publishing checks

Six categories of checks mapped to marketplace requirements, each failure with fix guidance and an autofix flow, plus live end-to-end runs inside the real clients.

Learn more

Cloud Inspector

Fire tool calls at your deployed server, read raw JSON-RPC frames, browse resources and preview widgets — against real clients, with no local setup.

Learn more

Public chat

Every deployment gets a shareable chat surface you can embed anywhere you already have an audience — no client install, no configuration.

Learn more

Analytics

Tool calls, sessions, error rates and latency percentiles broken down by client, client version, protocol version and country — with discovery traffic excluded by default.

Learn more

Everything on mcpfy Cloud shares one pipeline.