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Rust MCP Preflight

Official registry Other

Check an MCP Registry listing before you publish: README mcp-name line, server.json, name.

Source code Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

CARGO package rust-mcp-preflight

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. Rust MCP Preflight
  2. Install
  3. Use it from a terminal or CI
  4. Use it from an MCP client
  5. Where it fits
  6. Links
  7. License

Rust MCP Preflight

Check an MCP Registry listing before you publish it.

mcp-publisher validate checks the shape of server.json. It doesn't check that the registry will accept your package: that only happens at mcp-publisher publish, after the crate version is already on crates.io and can't be changed. Rust MCP Preflight runs those checks first.

  • The README line. Fetches the README crates.io serves for the exact crate version and looks for mcp-name: <your server name>, matched the way the registry matches it (ported from the registry's own validator). Catches the line hidden in an HTML comment (crates.io strips comments), the line glued to the next word, and a near miss such as the wrong case.
  • server.json. The rules mcp-publisher publish applies: $schema, the server name, and for every package exact versions (no latest, no ranges), the transport and no spaces in the identifier. For cargo packages also the crate version, no fileSha256 and registryBaseUrl. Plus warnings for runtimeHint, mismatched versions, and placeholders left over from mcp-publisher init.
  • The server name. The rules publish applies, whether it's already listed, and which login its namespace needs (including GitHub organizations, which login github can't publish to yet).

It only reads: crates.io, the official registry and the GitHub users API. It publishes nothing and needs no keys.

Install

cargo install rust-mcp-preflight

Use it from a terminal or CI

rust-mcp-preflight server.json

It prints one line per check and exits 1 if anything fails:

Preflight: server.json
  PASS  name "io.github.VoidNullable/lific" is a valid server name
  PASS  packages[0]: cargo crate "lific"
  WARN  VoidNullable is a GitHub organization: `mcp-publisher login github` can't publish to org namespaces yet (registry #1468). ...
  INFO  already listed: latest 2.11.1 (active). Your next publish needs a new version number
  PASS  README of lific 2.11.1 on crates.io contains `mcp-name: io.github.VoidNullable/lific`

Ready: no failures, 1 warning(s).

Use it from an MCP client

claude mcp add preflight -- rust-mcp-preflight
{ "mcpServers": { "preflight": { "command": "rust-mcp-preflight" } } }
ToolWhat it checks
preflightEverything below, from the text of server.json
check_server_jsonThe publish rules (offline)
check_readmeThe mcp-name: line in one crate version's README on crates.io
check_nameThe name's publish rules, listing and namespace login

Where it fits

The order is: cargo publish (with the line in the README), then rust-mcp-preflight server.json, then mcp-publisher login github and mcp-publisher publish.

The full walk-through: Listing a Rust MCP server in the official MCP Registry.

The README check and the crates.io rules are for cargo packages. Other package types (npm, PyPI, mcpb and so on) get the shared rules, and their registry's own checks are listed as not run.

If crates.io or the README can't be reached, the README counts as not checked and the result is a failure, so a CI run never passes on a README it didn't see.

Listed and live? Get a free report on the whole server, not just the listing: wolfejam.dev/#worth-it

License

MIT

About wolfejam

Frequently asked questions

What is Rust MCP Preflight?

Check an MCP Registry listing before you publish: README mcp-name line, server.json, name.

How do I install Rust MCP Preflight?

Follow the installation steps in its documentation, shown on this page and in its repository.

Does Rust MCP Preflight need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is Rust MCP Preflight open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains Rust MCP Preflight?

It is published by Wolfe-Jam. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.