MCPLoadTester

MCPLoadTester is a load testing toolkit for Model Context Protocol (MCP) servers.

It allows performance testing of MCP tools and agents using:

• Apache JMeter
• k6 (planned)
• CLI tools (planned)

Compatibility

Installation

This project now builds a thin plugin jar:

• plugin jar goes to JMETER_HOME/lib/ext
• runtime dependencies go to JMETER_HOME/lib

Recommended local install (plugin + dependencies)

JMETER_HOME=/path/to/apache-jmeter-5.6.3 ./gradlew installLocalWithDeps

Plugin-only local install

Use this only if dependencies are already managed elsewhere.

JMETER_HOME=/path/to/apache-jmeter-5.6.3 ./gradlew installLocal

Build artifact

./gradlew jar

Jar path:

build/libs/jmeter-mcp-sampler-.jar

Plugins Manager Custom Repo (Latest Release)

Each tagged release now publishes a Plugins Manager descriptor asset:

https://github.com/AndreyVMarkelov/MCPLoadTester/releases/latest/download/plugins-repo.json

To add this custom repo in JMeter, set in user.properties:

jpgc.repo.address=https://jmeter-plugins.org/repo/;https://github.com/AndreyVMarkelov/MCPLoadTester/releases/latest/download/plugins-repo.json

Then restart JMeter and open Plugins Manager. The catalog/display name is MCPLoadTester JMeter MCP Sampler.

Quick Start (2 Minutes)

Path note: commands and scripts/... arguments below are relative to this repository root.
Run JMeter from the repo root, or use absolute paths.

1. Install plugin (see Installation > Recommended local install above).
2. Restart JMeter.
3. Add sampler: Thread Group -> Add -> Sampler -> MCP Sampler.

4. Use local echo mock (stdio) with these sampler settings:
   • Transport: stdio
   • Command: python3
   • Arguments: scripts/mock_mcp_server.py
   • MCP Method: tools/list
   • Client name: jmeter-mcp-sampler (default)
   • Client version: 1.0.0 (default)

5. Add a Response Assertion:
   • Field to Test: Response Data
   • Pattern: echo

6. Run test and verify the assertion passes.

HTTP + SSE Quick Start

1. Start local mock HTTP+SSE server:

node scripts/mock_http_sse_mcp_server.js

2. In sampler set:

• Transport: http+sse
• HTTP base URL: http://127.0.0.1:8080
• SSE endpoint path: /events