MCP Tools (Model Context Protocol)
Use MCP servers as a tool source: discover tool schemas via tools/list, inject them into LLM calls, and keep execution host-owned.
Design principle
MCP is treated as a tool protocol, not an LLM provider. AbstractCore providers generate text/tool calls; your host/runtime decides what to execute and where.
Discover tool specs from an MCP server
AbstractCore converts MCP tool schemas into AbstractCore-compatible tool specs that you can pass to tools=[...].
from abstractcore import create_llm
from abstractcore.mcp import McpClient, McpToolSource
llm = create_llm("openai", model="gpt-5-mini")
# MCP Streamable HTTP transport (JSON-RPC over HTTP POST)
client = McpClient(url="http://localhost:3000/mcp")
tool_specs = McpToolSource(server_id="local", client=client).list_tool_specs()
response = llm.generate("Call an MCP tool if needed.", tools=tool_specs)
print(response.tool_calls)
Tools are namespaced to avoid collisions:
mcp::<server_id>::<tool_name>
Execute MCP tool calls (host/runtime)
By default, AbstractCore returns tool calls; it does not execute them. To execute MCP tool calls, parse the namespaced name and route to the correct server.
from abstractcore.mcp import McpClient, parse_namespaced_tool_name
client = McpClient(url="http://localhost:3000/mcp")
for call in response.tool_calls or []:
parsed = parse_namespaced_tool_name(call.get("name", ""))
if not parsed:
continue
server_id, tool_name = parsed.server_id, parsed.tool_name
args = call.get("arguments") or {}
# In a real host/runtime: look up server_id → client/connection
result = client.call_tool(name=tool_name, arguments=args)
print(server_id, tool_name, result)Security & operational guidance
- Whitelist tool servers: only connect to trusted MCP endpoints.
- Keep execution explicit: treat tool calls like untrusted user input; validate args and apply allowlists.
- Separate privileges: run high-privilege tools on hardened hosts/containers; consider separate tool workers.
- Auditability: log tool calls + results at the host boundary.