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ReferenceArcade MCPPythonTypes

Types

Core Pydantic models and enums for the protocol shapes.

arcade_mcp_server.types

CallToolResult

Bases: Result

A list of content objects that represent the unstructured result of the call.

content (instance-attribute)

An optional JSON object that represents the structured result of the call.

SessionMessage

Type: dataclass

Wrapper for messages in transport sessions.

Examples

Constructing a JSON-RPC request and response model

Python
from arcade_mcp_server.types import JSONRPCRequest, JSONRPCResponse
 
req = JSONRPCRequest(id=1, method="ping", params={})
res = JSONRPCResponse(id=req.id, result={})
print(req.model_dump_json())
print(res.model_dump_json())

Building a tools/call request and examining result shape

Python
from arcade_mcp_server.types import CallToolRequest, CallToolResult, TextContent
 
call = CallToolRequest(
    id=2,
    method="tools/call",
    params={
        "name": "Toolkit.tool",
        "arguments": {"text": "hello"},
    },
)
# Result would typically be produced by the server:
result = CallToolResult(
    content=[TextContent(type="text", text="Echo: hello")],
    structuredContent={"result": "Echo: hello"},
    isError=False
)
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