Multimeter

io.github.mshobeyriPublished by GitHub account mshobeyriv1.42.4Updated Oct 24, 2026

Scaffold, validate, format, and run YAML .mmt API tests. Do not invent syntax.

VerifiedSTDIODesktop onlyDeveloper ToolsAI & ML

Overview

AI-generated overview

Lets an assistant scaffold, validate, format, and run YAML .mmt API tests kept in Git.

What you can do
Multimeter is a Git-native API testing tool whose requests, tests, mocks, and docs are YAML .mmt files in a repository. Its MCP server, mmt-mcp, exposes four tools to an assistant: scaffold_test, validate, format, and run. This lets the assistant generate tests from an API or a description, check and format the definitions, and execute them, with the same files used locally and in CI.
When to use it
Worth adding when a project keeps its API tests as .mmt YAML files in Git and you want an assistant to write, check, or run them alongside the code. It suits teams that already use Multimeter in VS Code or its testlight CLI and want AI generation and execution in the same files.
Requirements
Runs as a local stdio process on the user's machine, installed from the npm package mmt-mcp. Desktop only; no web executable. No authentication, environment variables, or headers are declared. The README describes Multimeter as a VS Code-native extension, so the extension and its workflow are the intended context.
Before you install
The run tool executes the API tests defined in .mmt files, which can send requests to external services and may change data on the systems they target. Test files can reference environment variables, so review what a generated or edited test points at before running it. The README also mentions AI judges that can call a model, including a cloud model, which may send API responses to a third party.

Installation

In SourceWeft

  1. Open Multimeter in the dashboard and add it to a workspace.
  2. 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

[Logo]
Git-native REST client and API tests in VS Code. YAML .mmt files in Git.

Demo · Website · Request Feature · VS Code · CLI · GitHub Action · Docs · llms.txt

[VS Code Installs] [npm downloads] [Version] [License]

[Multimeter — Get Started, YAML, and API tester]

🚀 Start with a request. Grow into a platform.

Multimeter is Git-native API testing in VS Code. Requests, tests, mocks, and docs are YAML .mmt files in your repo.

Start with a single HTTP request.

Grow into tests, suites, mocks, reports, documentation, and CI when you need them.

All in the same tool. No migration. No second product.

🎯 What you get

Simple by default

  • ✅ Git-native, file-based YAML
  • ✅ Lightweight — no account, no cloud lock-in
  • ✅ Collaboration through pull requests, like code
  • ✅ The same files locally and in CI

A full testing platform when you need it

  • ✅ HTTP, WebSocket, GraphQL, and gRPC
  • ✅ Multi-step flows and test suites
  • ✅ Mock servers
  • ✅ Generated documentation
  • ✅ Reports
  • ✅ CI with testlight

AI in the same files

  • ✅ Generate tests from an API or a description (Cursor, Copilot, Claude via MCP)
  • ✅ Judge replies — semantic similarity, or open-ended checks like how funny a response is
  • ✅ Bring your own model (Ollama or cloud)

See all features →

⚡ Start simple

Multimeter is a VS Code-native extension. All you need:

There you run a POST request as follows:

yaml
type: apititle: Simple POSTurl: https://test.mmt.dev/echomethod: postformat: jsonbody:  message: hello

That's enough.

  • No suites.
  • No mocks.
  • No workflows.
  • No complexity.

🧪 Need tests?

yaml
type: teststeps:  - http: https://test.mmt.dev/echo    method: get    expect:      status: 200
  • Still simple.
  • Still Git-native.
  • Still easy to review.

🚀 Scale without switching tools

As your project grows, Multimeter grows with it.

Add:

  • Test suites
  • Mock servers
  • Documentation
  • Workflow execution
  • Structured reporting
  • CI artifacts

Only when you need them.

Everything stays in the same ecosystem.

See all examples →

🤖 MCP, AI generation, and AI judges

Cursor, Copilot, and Claude write and run the same .mmt files you edit in VS Code. MCP (mmt-mcp) gives them scaffold_test, validate, format, and run — generate tests from an API or a description, then keep them in Git.

Judge an API answer in the same test. Compare semantic similarity to an expected reply, or check something open-ended — for example, how funny the response is. Bring your own model (Ollama or cloud). An alternative to a separate Promptfoo eval stack.

See MCP docs · Judge docs

🔁 Built for reliable CI

Multimeter validates test definitions before execution.

That means:

  • ✅ Earlier feedback
  • ✅ More deterministic execution
  • ✅ Fewer surprises in CI
  • ✅ Easier debugging
  • ✅ Reproducible results

GitHub Actions:

yaml
- uses: actions/checkout@v6- uses: mshobeyri/testlight-action@v1  with:    file: tests/suite.mmt    report: junit    report-file: results/junit.xml

Or from a terminal using the Multimeter CLI called testlight.

sh
npm install -g mmt-testlighttestlight run tests/suite.mmt

See the GitHub Action and Testlight install.

📦 Everything stays in Git

Your code, tests, mocks, documentation, reports, and environment settings live in the same repository.

  • ✅ Version controlled
  • ✅ Code and tests evolve together
  • ✅ Reviewable through pull requests
  • ✅ Easy to move and share
  • ✅ No platform lock-in
  • ✅ AI can update code and tests together
  • ✅ Environment variables never go missing
  • ✅ Historical test results stay with the project

🧠 Philosophy

Most API tools focus on requests.

Multimeter focuses on behavior.

Instead of asking:

"Did this request return the expected response?"

Multimeter helps you answer:

"Does this system still behave correctly?"

License

Multimeter is licensed under the Apache License 2.0.

Demos · Documentation · Website · GitHub

Source: README.md at commit 2a74b1c

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

2
  1. v1.42.4LatestSep 16, 2026
  2. v1.42.2-preSep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • 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
  • License10 pts