MCP tool failure isolation in AgentOS

mcp_errors.py

"""
Example demonstrating MCP tool failure isolation in AgentOS.

This example shows that when an AgentOS app includes multiple agents - some with MCP tools
and some without - a connection failure to an MCP server should NOT cause the entire app
to fail. Only the agent using the failing MCP tool should be affected.

Run this example with:
    python cookbook/05_agent_os/mcp_demo/mcp_tools_failure_isolation.py

Then test the endpoints:
    1. GET http://localhost:7777/agents - Should return both agents (even if MCP fails)
    2. POST http://localhost:7777/agents/basic-agent/runs - Should work (no MCP dependency)
    3. POST http://localhost:7777/agents/mcp-agent/runs - May fail if MCP server unavailable
"""

from agno.agent import Agent
from agno.db.sqlite import SqliteDb
from agno.models.openai import OpenAIChat
from agno.os import AgentOS
from agno.tools.mcp import MCPTools

# Setup the database
db = SqliteDb(db_file="tmp/mcp_failure_test.db")

# Agent 1: Basic agent without MCP tools - should always work
basic_agent = Agent(
    id="basic-agent",
    name="Basic Agent",
    description="A simple agent without MCP tools",
    model=OpenAIChat(id="gpt-4o-mini"),
    db=db,
    instructions="You are a helpful assistant.",
    markdown=True,
)

# MCP tools pointing to a non-existent server (simulating failure)
# This will fail to connect during startup
failing_mcp_tools = MCPTools(
    transport="streamable-http",
    url="http://localhost:9999/nonexistent-mcp-server",  # This server doesn't exist
    timeout_seconds=5,
)

# Agent 2: Agent with MCP tools that may fail
mcp_agent = Agent(
    id="mcp-agent",
    name="MCP Agent",
    description="An agent with MCP tools that may fail to connect",
    model=OpenAIChat(id="gpt-4o-mini"),
    db=db,
    tools=[failing_mcp_tools],
    instructions="You are an assistant with MCP tools.",
    markdown=True,
)

# Create AgentOS with both agents
# The expectation: If MCP connection fails, basic_agent should still be accessible
agent_os = AgentOS(
    name="MCP Failure Isolation Test",
    description="Test app demonstrating MCP failure isolation",
    agents=[basic_agent, mcp_agent],
)

app = agent_os.get_app()

if __name__ == "__main__":
    """Run the AgentOS.

    Expected behavior:
    - The app should start even if MCP connection fails
    - GET /agents should list both agents
    - POST /agents/basic-agent/runs should work normally
    - POST /agents/mcp-agent/runs should gracefully handle MCP unavailability

    Current behavior (bug):
    - If MCP connection fails, the entire app fails to start with 500 error
    """
    agent_os.serve(app="test:app", port=7777)