- Added MCP tool invocation to API with flow-specific 'mcp_tool'

method.
- Added tg-invoke-mcp-tool to make it easy to test the MCP integration
  part without using an agent flow.

trustgraph-base/trustgraph/api/flow.py

@@ -4,6 +4,7 @@ import base64
 
 from .. knowledge import hash, Uri, Literal
 from . types import Triple
+from . exceptions import ProtocolException
 
 def to_value(x):
     if x["e"]: return Uri(x["v"])
@@ -197,7 +198,6 @@ class FlowInstance:
 
     def prompt(self, id, variables):
 
-        # The input consists of system and prompt strings
         input = {
             "id": id,
             "variables": variables
@@ -221,12 +221,37 @@ class FlowInstance:
 
         raise ProtocolException("Response not formatted correctly")
 
+    def mcp_tool(self, name, parameters={}):
+
+        # The input consists of name and parameters
+        input = {
+            "name": name,
+            "parameters": parameters,
+        }
+
+        object = self.request(
+            "service/mcp-tool",
+            input
+        )
+
+        if "text" in object:
+            return object["text"]
+
+        if "object" in object:
+            try:
+                return object["object"]
+            except Exception as e:
+                raise ProtocolException(
+                    "Returned object not well-formed JSON"
+                )
+
+        raise ProtocolException("Response not formatted correctly")
+
     def triples_query(
             self, s=None, p=None, o=None,
             user=None, collection=None, limit=10000
     ):
 
-        # The input consists of system and prompt strings
         input = {
             "limit": limit
         }

trustgraph-cli/scripts/tg-invoke-mcp-tool

@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+
+"""
+Invokes MCP (Model Control Protocol) tools through the TrustGraph API.
+Allows calling MCP tools by specifying the tool name and providing
+parameters as a JSON-encoded dictionary. The tool is executed within
+the context of a specified flow.
+"""
+
+import argparse
+import os
+import json
+from trustgraph.api import Api
+
+default_url = os.getenv("TRUSTGRAPH_URL", 'http://localhost:8088/')
+
+def query(url, flow_id, name, parameters):
+
+    api = Api(url).flow().id(flow_id)
+
+    resp = api.mcp_tool(name=name, parameters=parameters)
+
+    if isinstance(resp, str):
+        print(resp)
+    else:
+        print(json.dumps(resp, indent=4))
+
+def main():
+
+    parser = argparse.ArgumentParser(
+        prog='tg-invoke-mcp-tool',
+        description=__doc__,
+    )
+
+    parser.add_argument(
+        '-u', '--url',
+        default=default_url,
+        help=f'API URL (default: {default_url})',
+    )
+
+    parser.add_argument(
+        '-f', '--flow-id',
+        default="default",
+        help=f'Flow ID (default: default)'
+    )
+
+    parser.add_argument(
+        '-n', '--name',
+        metavar='tool-name',
+        help=f'MCP tool name',
+    )
+
+    parser.add_argument(
+        '-P', '--parameters',
+        help='''Tool parameters, should be JSON-encoded dict.''',
+    )
+
+    args = parser.parse_args()
+
+
+    if args.parameters:
+        parameters = json.loads(args.parameters)
+    else:
+        parameters = {}
+
+    try:
+
+        query(
+            url = args.url,
+            flow_id = args.flow_id,
+            name = args.name,
+            parameters = parameters,
+        )
+
+    except Exception as e:
+
+        print("Exception:", e, flush=True)
+
+main()
+

trustgraph-cli/setup.py

@@ -56,6 +56,7 @@ setuptools.setup(
         "scripts/tg-invoke-document-rag",
         "scripts/tg-invoke-graph-rag",
         "scripts/tg-invoke-llm",
+        "scripts/tg-invoke-mcp-tool",
         "scripts/tg-invoke-prompt",
         "scripts/tg-load-doc-embeds",
         "scripts/tg-load-kg-core",