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https://github.com/trustgraph-ai/trustgraph.git
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e56186054a
- MCP client service - Tool request/response schema - API gateway support for mcp-tool - Message translation for tool request & response - Make mcp-tool using configuration service for information about where the MCP services are.
105 lines
2.7 KiB
Python
Executable file
105 lines
2.7 KiB
Python
Executable file
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"""
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MCP tool-calling service, calls an external MCP tool. Input is
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name + parameters, output is the response, either a string or an object.
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"""
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import json
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from mcp.client.streamable_http import streamablehttp_client
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from mcp import ClientSession
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from ... base import ToolService
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default_ident = "mcp-tool"
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class Service(ToolService):
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def __init__(self, **params):
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super(Service, self).__init__(
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**params
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)
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self.register_config_handler(self.on_mcp_config)
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self.mcp_services = {}
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async def on_mcp_config(self, config, version):
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print("Got config version", version)
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if "mcp" not in config: return
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self.mcp_services = {
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k: json.loads(v)
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for k, v in config["mcp"].items()
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}
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async def invoke_tool(self, name, parameters):
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try:
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if name not in self.mcp_services:
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raise RuntimeError(f"MCP service {name} not known")
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if "url" not in self.mcp_services[name]:
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raise RuntimeError(f"MCP service {name} URL not defined")
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url = self.mcp_services[name]["url"]
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if "name" in self.mcp_services[name]:
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remote_name = self.mcp_services[name]["name"]
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else:
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remote_name = name
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print("Invoking", remote_name, "at", url, flush=True)
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# Connect to a streamable HTTP server
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async with streamablehttp_client(url) as (
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read_stream,
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write_stream,
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_,
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):
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# Create a session using the client streams
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async with ClientSession(read_stream, write_stream) as session:
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# Initialize the connection
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await session.initialize()
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# Call a tool
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result = await session.call_tool(
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remote_name,
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parameters
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)
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if result.structuredContent:
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return result.structuredContent
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elif hasattr(result, "content"):
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return "".join([
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x.text
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for x in result.content
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])
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else:
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return "No content"
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except BaseExceptionGroup as e:
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for child in e.exceptions:
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print(child)
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raise e.exceptions[0]
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except Exception as e:
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print(e)
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raise e
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@staticmethod
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def add_args(parser):
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ToolService.add_args(parser)
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def run():
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Service.launch(default_ident, __doc__)
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