testgen-eval

Step 1 of a learning project: an MCP server that wraps testgen's test-suite generation as a callable tool, plus (in later steps) an eval harness that judges what it produces.

This is deliberately not a reimplementation of testgen — it's a thin MCP front door onto testgen's existing POST /api/generate HTTP endpoint. The point of this step is to learn MCP by wiring up something real, and to give the eval harness (steps 3-4) a tool it can actually call.

Prerequisite

testgen must be running locally:

cd ../testgen
.venv\Scripts\activate
testgen serve

This server must stay up at http://127.0.0.1:8000 while you use the MCP server below.

Related MCP server: EvalView

Setup

npm install

Run

npm run dev

This starts the MCP server on stdio (no visible output on success — stdio servers are meant to be driven by an MCP client, not run standalone in a terminal you're watching).

Try it out

The easiest way to see the protocol working and manually call the tool is the official MCP Inspector:

npx @modelcontextprotocol/inspector tsx src/index.ts

This opens a local web UI. You should see one tool, generate_test_suite — call it with a requirement (and optionally instructions/model) and you'll get back the same TestSuite JSON testgen's CLI/web UI would produce.

Structure

• src/testgenClient.ts — the only file that knows testgen's HTTP API shape.

• src/server.ts — the MCP server and its one tool, generate_test_suite.

• src/index.ts — entrypoint; connects the server to a stdio transport.