MCP Server — JustAPI Docs

Register Tools

Expose your routes as MCP tools:

from justapi import JustAPIApp

app = JustAPIApp()

@app.tool
def get_weather(city: str) -> dict:
    """Get current weather for a city."""
    return {"city": city, "temp": 72, "condition": "sunny"}

@app.tool(name="search_db", description="Search the database")
def search(query: str) -> list:
    return db.search(query)

List Tools

tools = app.list_tools()
# Returns list of MCP tool descriptors

Call Tools

result = app.call_tool("get_weather", {"city": "London"})
# Returns: {"city": "London", "temp": 72, "condition": "sunny"}

Built-in MCP Tools

JustAPI registers these introspection tools automatically:

Tool	Description
`list_routes`	List all registered API routes
`get_signature`	Full signature for one route
`explain_endpoint`	Natural-language explanation of an endpoint
`generate_snippet`	Client code snippet for an endpoint

MCP Server CLI

Run the MCP stdio server for agent integration:

python -m justapi.mcp_server --base-url http://localhost:8000

System Routes

With app.enable_system_routes(), these routes expose tool data:

Route	Description
`/_system/tools`	List registered tools
`/_system/tools/call`	Invoke a tool by name
`/_system/help`	Rich route descriptors
`/_system/help/{name}`	Detailed help for one route