letin: Power Query (M)

io.github.S-CurveLabsPublished by GitHub account S-CurveLabsv0.2.0Updated Oct 24, 2026

Inspect, refactor, lint, run and version Power Query (M) in Excel workbooks and Power BI projects.

VerifiedSTDIODesktop onlyDeveloper Tools Data & Analytics

Server details

Identifier: io.github.S-CurveLabs/letin
Transport: STDIO
Runtime: Desktop only
Trust: Verified
Published: Sep 22, 2026

Security note

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Overview

AI-generated overview

A local MCP server that lets an assistant inspect, refactor, lint, run and version Power Query (M) code in Excel workbooks and Power BI projects.

What you can do: Inspect Power Query (M) code inside Excel workbooks and Power BI projects, including queries and their structure. Refactor and lint M code, with query snapshots kept for versioning. Run M queries so results can be checked. Track changes to queries over time through stored snapshots.
When to use it: Useful when working on Power Query or Power BI data preparation and you want an assistant to review, clean up, lint or test M code rather than editing it by hand. Best suited to desktop work on local workbook and project files.
Requirements: Runs as a local process on the user's machine, launched with uvx from the letin PyPI package, so Python and uv are needed. Desktop only; no web execution. The optional LETIN_HOME environment variable sets where query snapshots are stored, defaulting to a folder under LOCALAPPDATA. No authentication is declared.

Before you install

It reads and can change Power Query code in your Excel workbooks and Power BI projects, and running queries may execute the data transformations they define. Snapshot copies of queries are written to the LETIN_HOME folder, so that location may hold workbook content. Review changes before saving over real files and keep backups.

Installation

In SourceWeft

Open letin: Power Query (M) in the dashboard and add it to a workspace.
Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

This repository has no README.

Tools

SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

v0.2.0LatestSep 22, 2026

Score

25% of the applicable checks met

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Auth declared10 pts
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Tools listed15 pts
Answer tools/list without a credential, or ship a package that starts in a sandbox without one.
DescriptionRequired15 pts
Logo10 pts
Documentation15 pts
Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.
License10 pts
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