v1.0.0 — Initial Release

mcp-testkit v1.0.0

The missing testing framework for MCP (Model Context Protocol) servers.

Features

• Test Harness — One-line setup for in-memory or stdio MCP testing
• Custom Matchers — toHaveToolNamed(), toBeSuccessful(), toHaveTextContent(), and more
• Schema Validation — Validate tool schemas against MCP best practices
• Input Generation — Generate valid and edge-case inputs from JSON Schema
• Fuzz Testing — Reproducible fuzz testing with seeded PRNG
• Snapshot Support — Deterministic snapshot serializer (strips _meta, _timestamp, etc.)
• Text Helpers — getTexts(), getFirstText(), hasText() utilities

Install

npm install -D mcp-testkit @modelcontextprotocol/sdk zod

Quick Start

import { createHarness } from "mcp-testkit";
import { mcpMatchers } from "mcp-testkit/matchers";

expect.extend(mcpMatchers);

const harness = await createHarness(server);
const result = await harness.callTool("greet", { name: "World" });
expect(result).toBeSuccessful();
expect(result).toHaveTextContent("Hello, World!");

See README for full documentation.