MCP-Hurl (Mcph)

MCP-Hurl is a declarative testing DSL for MCP servers. Hurl-inspired .mcph syntax with a custom Python async runner. Transport-agnostic — stdio and Streamable HTTP.

CONNECT stdio "python -m my_mcp_server"
INITIALIZE protocolVersion="2025-03-26"
CLIENT name="Mcph" version="1.0.0"
  CAPABILITIES roots=true

ASSERT STATUS == 200
ASSERT serverInfo.name == "MyServer"

LIST tools
ASSERT STATUS == 200
ASSERT tools COUNT >= 1

CALL "run_sql" { "query": "SELECT 1;" }
ASSERT STATUS == 200
ASSERT isError == false

SHUTDOWN

Quick Start

git clone https://github.com/rmax-ai/mcph
cd mcph
uv run mcph run examples/conformance.mcph

Why Mcph?

The Model Context Protocol is the standard interface between LLMs and tools. But as organizations deploy MCP servers, verifying protocol compliance remains a gap. Existing API testing tools are optimized for stateless HTTP — they can't handle stdio subprocesses, JSON-RPC multiplexing, or the MCP capability handshake.

Mcph solves this with:

• Hurl-inspired syntax — readable, self-documenting, executable
• First-class JSON-RPC — request IDs, error codes, notifications
• Transport-agnostic — stdio subprocesses and Streamable HTTP
• Structural assertions — JSONPath, regex, fuzzy types, schema validation
• Capability-aware — skip tests for features the server doesn't support
• CI-native — JUnit XML, JSON reports, exit codes

Features

Get started →