Pydantic AI Agents

Call Pydantic AI Agents via LiteLLM's A2A Gateway.

Property	Details
Description	Pydantic AI agents with native A2A support via the `to_a2a()` method. LiteLLM provides fake streaming support for agents that don't natively stream.
Provider Route on LiteLLM	A2A Gateway
Supported Endpoints	`/v1/a2a/message/send`
Provider Doc	Pydantic AI Agents ↗

LiteLLM A2A Gateway

All Pydantic AI agents need to be exposed as A2A agents using the to_a2a() method. Once your agent server is running, you can add it to the LiteLLM Gateway.

1. Setup Pydantic AI Agent Server

LiteLLM requires Pydantic AI agents to follow the A2A (Agent-to-Agent) protocol. Pydantic AI has native A2A support via the to_a2a() method, which exposes your agent as an A2A-compliant server.

Install Dependencies

pip install pydantic-ai fasta2a uvicorn

Create Agent

agent.py
from pydantic_ai import Agent

agent = Agent('openai:gpt-4o-mini', instructions='Be helpful!')

@agent.tool_plain
def get_weather(city: str) -> str:
    """Get weather for a city."""
    return f"Weather in {city}: Sunny, 72°F"

@agent.tool_plain  
def calculator(expression: str) -> str:
    """Evaluate a math expression."""
    return str(eval(expression))

# Native A2A server - Pydantic AI handles it automatically
app = agent.to_a2a()

Run Server

uvicorn agent:app --host 0.0.0.0 --port 9999

Server runs at http://localhost:9999

2. Navigate to Agents

From the sidebar, click "Agents" to open the agent management page, then click "+ Add New Agent".

3. Select Pydantic AI Agent Type

Click "A2A Standard" to see available agent types, then select "Pydantic AI".

Select A2A Standard

Select Pydantic AI

4. Configure the Agent

Fill in the following fields:

Agent Name - A unique identifier for your agent (e.g., test-pydantic-agent)
Agent URL - The URL where your Pydantic AI agent is running. We use http://localhost:9999 because that's where we started our Pydantic AI agent server in the previous step.

Enter Agent Name