Wassette

Wassette A security-oriented runtime that runs WebAssembly Components via MCP

[Quick Start] | [FAQ] | [Documentation] | [Releases] | [Contributing] | [Discord]

> [!WARNING] > Early Development: This repository is not production ready yet. It is in early development and may change significantly.

Why Wassette?

• Convenience: Wassette makes it easy to extend AI agents with new tools,

all without ever having to leave the chat window.

• Reusability: Wasm Components are generic and reusable;

there is nothing MCP-specific about them.

• Security: Wassette is built on the Wasmtime security sandbox, providing

browser-grade isolation of tools.

Architecture

Installation

Quick start: For Linux/macOS, use our one-liner install script:

curl -fsSL https://raw.githubusercontent.com/microsoft/wassette/main/install.sh | bash

For complete installation instructions for all platforms (including Windows, Homebrew, Nix, Docker, and more), see our Installation Guide.

Using Wassette

With Wassette installed, the next step is to register it with your agent of choice. See our [Quick Start] guide (3 simple steps), or check the MCP Clients guide for detailed setup instructions for GitHub Copilot, Cursor, Claude Code, and Gemini CLI.

Once configured, you can start loading WebAssembly components. To teach your agent to tell the time, ask it to load a time component:

Please load the time component from oci://ghcr.io/microsoft/time-server-js:latest

Now that the time component is loaded, we can ask your agent to tell you the current time:

What is the current time?

The agent will respond with the current time, which is fetched from the time component running in a secure WebAssembly sandbox:

The current time July 31, 2025 at 10:30 AM UTC

Congratulations! You've just run your first Wasm Component and taught your agent how to tell time!

Demo

https://github.com/user-attachments/assets/8e5a371c-ac72-406d-859c-03833ee83963

Discord

You can join us via the #wassette channel on the Microsoft Open Source Discord:

[](https://discord.gg/microsoft-open-source)

Contributing

Please see [CONTRIBUTING.md][Contributing] for more information on how to contribute to this project.

License

This project is licensed under the MIT License.

Trademarks

This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft’s Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party’s policies.

[Quick Start]: https://microsoft.github.io/wassette/latest/quick-start.html [FAQ]: https://microsoft.github.io/wassette/latest/faq.html [Documentation]: https://microsoft.github.io/wassette [Contributing]: CONTRIBUTING.md [Releases]: https://github.com/microsoft/wassette/releases [Discord]: https://discord.gg/microsoft-open-source

Contributors

Thanks to all contributors who are helping shape Wassette into something great.

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: microsoft
• Source: microsoft/wassette
• License: MIT
• Homepage: https://microsoft.github.io/wassette/

Install and usage instructions live in the source repository linked above.