Fsh MCP Server

Sushi Unshortens Short Hand Inputs (FSH Compiler)

Local serverstdioTypeScript

What is the Fsh MCP server?

Most developer tooling work still happens through a UI a human drives. Fsh MCP server moves it into the conversation instead. Sushi Unshortens Short Hand Inputs (FSH Compiler).

The short version

SUSHI (aka "SUSHI Unshortens Short Hand Inputs") is a reference implementation command-line interpreter/compiler for FHIR Shorthand (FSH).

The tools it exposes

The server publishes 8 tools. What each one is for:

  • Maintainers — This project is maintained by the HL7 community
  • Task — Description
  • build — compiles src//*.ts files to dist//*.js files using the TypeScript compiler (tsc)
  • test — runs all unit tests using Jest
  • lint — checks all src files to ensure they follow project code styles and rules
  • prettier — checks all src files to ensure they follow project formatting conventions
  • check — runs all the checks performed as part of ci (test, lint, prettier)
  • regression — runs regression against repositories found by FSHFinder

Getting it running

The server ships on npm as fsh-sushi, so your MCP client can launch it on demand — there is no separate build step. Add the server block to your client's configuration, restart it, and the tools register themselves.

How it compares

This sits in the developer tooling group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Fsh's toolset — Maintainers, Task, build and 5 more — is a fair guide to whether it matches your workflow. It is maintained by cmoesel; worth a glance at recent repository activity before you build anything load-bearing on it.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.

Things to watch

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

Available tools

ToolWhat it does
MaintainersThis project is maintained by the HL7 community.
TaskDescription
buildcompiles src/**/*.ts files to dist/**/*.js files using the TypeScript compiler (tsc)
testruns all unit tests using Jest
lintchecks all src files to ensure they follow project code styles and rules
prettierchecks all src files to ensure they follow project formatting conventions
checkruns all the checks performed as part of ci (test, lint, prettier)
regressionruns regression against repositories found by FSHFinder

How to install the Fsh MCP server

{
  "mcpServers": {
    "sushi": {
      "command": "npx",
      "args": ["-y", "fsh-sushi"]
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Example prompts to try

  • Use Fsh to Maintainers.
  • Use Fsh to Task.
  • Use Fsh to build.

Frequently asked questions

It connects Fsh to MCP-compatible AI assistants such as Claude and Cursor, exposing 8 tools (Maintainers, Task, build, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Fsh directly.