Testing¶

MCP Generator creates auto-generated test suites and supports the official MCP Inspector for interactive debugging.

Auto-Generated Tests¶

Every generated server includes test files that verify tool discovery, execution, and resource availability.

cd examples/petstore
uv run python test/run_tests.py

The test runner:

Starts the generated server on a random port
Connects via the MCP client
Calls tools/list to verify all tools are registered
Executes sample tool calls
Reports results

MCP Inspector¶

The MCP Inspector is the official debugging tool for MCP servers.

Quick Start¶

cd generated_mcp

# Interactive UI (recommended for development)
uv run fastmcp dev swagger_petstore_openapi_mcp_generated.py:create_server

# Or with the Inspector directly
npx @modelcontextprotocol/inspector python swagger_petstore_openapi_mcp_generated.py

The Inspector opens a browser UI at http://localhost:6274 where you can:

List and test all tools with interactive parameter forms
Browse resources hierarchically
Test prompts with streaming visualization
Debug with request/response history and timing

Tip

When using fastmcp dev or fastmcp run, always include :create_server to properly compose the modular architecture.

CLI Mode¶

For CI/CD and scripting:

# List tools
npx @modelcontextprotocol/inspector --cli \
  python swagger_petstore_openapi_mcp_generated.py \
  --method tools/list

# Call a tool
npx @modelcontextprotocol/inspector --cli \
  python swagger_petstore_openapi_mcp_generated.py \
  --method tools/call \
  --tool-name create_pet \
  --tool-arg 'name=Fluffy' \
  --tool-arg 'status=available'

Testing HTTP Transport¶

# Start server in HTTP mode
python swagger_petstore_openapi_mcp_generated.py --transport http --port 8000

# Connect Inspector via Streamable HTTP
npx @modelcontextprotocol/inspector http://localhost:8000/mcp --transport http

Unit Tests¶

Run the generator's own test suite:

# All tests
uv run pytest

# With coverage
uv run pytest --cov=mcp_generator

# Specific test
uv run pytest test/test_generator.py -v

Example Tests¶

Run the pre-built example tests:

# Run all example tests
uv run python scripts/test_examples.py

# Or individually
cd examples/petstore
uv run python test/run_tests.py