toolbelt

Modulewise Toolbelt

A Model Context Protocol (MCP) Server that exposes Wasm Components as Tools.

This is currently an early-stage non-production prototype.

(auth, observability, and OCI support are on the roadmap)

Run

One or more .wasm files may be provided as command line arguments (see example-components):

cargo run -- hello.wasm calculator.wasm

By default, components operate in a least-privilege capability mode. If your component requires capabilities from the host runtime, use a .toml file:

[flights]
uri="file:///path/to/flight-search.wasm"
capabilities=["http"]

Then pass that to the server instead of a direct .wasm file:

cargo run -- flights.toml

[!TIP]

Multiple components can be defined within a single .toml file, and capabilities are optional (uri is required). Currently supported capabilities are: http, inherit-network, and allow-ip-name-lookup

Test with MCP Inspector

1. Run the server as described above.

2. Start the MCP Inspector.

3. Ensure the SSE Transport Type is selected.

4. Ensure the specified URL is http://127.0.0.1:3001/sse (or replace host and port if not using defaults).

5. Click Connect and then List Tools.

6. Select a Tool, provide parameter values, and click Run Tool.

License

Copyright (c) 2025 Modulewise Inc and the Modulewise Toolbelt contributors.

Apache License v2.0: see LICENSE for details.