How to Use the U.S. Congress MCP in Pydantic AI

Q: Can the Pydantic AI framework handle complex U.S. Congress relationships?

Yes. You can list committee membership via listcongresscommittees and then use that structured data to perform relationship mapping, all while maintaining type-safety.

Q: Is the MCP Server reliable for historical U.S. Congress records using Pydantic AI?

It is. Tools like listcongresssessions provide clear start/end dates, and because of the validation layer, you're guaranteed to get structured data, even from older periods.

Get guaranteed data correctness when querying U.S. Congress with Pydantic AI.

See Vinkius in Action

Works with every AI agent you already use

…and any MCP-compatible client

MCP Servers - Free for Subscribers

Connect U.S. Congress MCP to Pydantic AI

Create your Vinkius account to connect U.S. Congress to Pydantic AI and route execution through our secure gateway. The platform manages server hosting, runtime updates, and security layers. Configuration requires no manual server provisioning.

GDPR Free for Subscribers

Setup U.S. Congress with Pydantic AI

Ask AI about this MCP

ChatGPT

Claude

Perplexity

Validate Bill Details with Pydantic AI

Use `get_bill_details` to pull full legislative records for a bill. The standout feature is that your agent validates the response against a Pydantic model. If the API sends unexpected data, your agent fails loudly—you never get silent corruption.

List Treaties via MCP Server

The `list_congress_treaties` tool retrieves treaties handled by Congress. This gives you a clean, type-safe list of documents. You know exactly what fields to expect, making your multi-agent workflow incredibly reliable.

Check Amendments with Pydantic AI

The `list_congress_amendments` tool provides a record of legislative amendments. Because every output is validated against a schema, you can trust that the data structure your agent receives for these complex records is correct.

Setup guide

Set up U.S. Congress MCP in Pydantic AI

Prerequisites

Python 3.10+ installed
pydantic-ai-slim[fastmcp] package
Active Vinkius subscription with a valid endpoint token

1

Install Pydantic AI with FastMCP
Run pip install "pydantic-ai-slim[fastmcp]". The FastMCP toolset replaces the deprecated MCPServerHTTP class with full protocol support.
2

Configure the FastMCPToolset
Pass a JSON-style config dict to FastMCPToolset with your Vinkius URL. Replace [YOUR_TOKEN_HERE] with your token from cloud.vinkius.com. Supports Streamable HTTP, SSE, and Stdio transports.
3

Create and run your agent
Pass the toolset to Agent(toolsets=[toolset]) and call agent.run(). Swap openai:gpt-4o for any supported model — Anthropic, Google, Mistral, or Groq.

agent.py

from pydantic_ai import Agent
from pydantic_ai.toolsets.fastmcp import FastMCPToolset

toolset = FastMCPToolset({
    "mcpServers": {
        "us-congress-mcp": {
            "url": "https://edge.vinkius.com/[YOUR_TOKEN_HERE]/mcp"
        }
    }
})

agent = Agent(
    "openai:gpt-4o",
    toolsets=[toolset],
    system_prompt="You have access to U.S. Congress tools.",
)

result = await agent.run("List recent U.S. Congress transactions")
print(result.output)

Get your connection token →

Independent Platform Disclaimer: Vinkius is an independent platform and is not affiliated with, endorsed by, sponsored by, verified by, or otherwise authorized by Congress.gov. All third-party trademarks, logos, and brand names are the property of their respective owners. Their use on this website is strictly for informational purposes to identify service compatibility and interoperability.

Why Choose Vinkius

Vinkius connects your tools to AI with real-time monitoring and automatic cost savings — all from one dashboard.

Connect U.S. Congress now

Real-time monitoring

Live

visibility into every interaction

Connect your favorite tools to your AI and see exactly what's happening — every request, every response, in real time.

Built-in savings

60%

lower AI costs

Vinkius compresses data between your apps and your AI automatically. Lower bills every month — no configuration required.

Single dashboard

One

place for every integration

Every tool your AI connects to, managed from a single screen. One account, complete control.

Common questions about U.S. Congress MCP in Pydantic AI

The MCP Server provides the raw tools, but Pydantic-AI adds a crucial layer of runtime validation. Your agent calls the tool, and we guarantee the output conforms to your specified Python models.

You've got access to everything: bills, members, nominations, committees, and full records for historical sessions. It’s a complete legislative dataset.

Yes. You can list committee membership via `list_congress_committees` and then use that structured data to perform relationship mapping, all while maintaining type-safety.

It is. Tools like `list_congress_sessions` provide clear start/end dates, and because of the validation layer, you're guaranteed to get structured data, even from older periods.

This MCP Server handles legislative bill details. The schema validation ensures that your agent only uses and validates the structured text fields provided by the tool.

Use it with your favorite AI tools

Connect this server to Cursor, Claude, VS Code, and more.

OpenAI Agents SDK sdk-python

Google ADK sdk-python

Pydantic AI sdk-python

Vercel AI SDK sdk-typescript