Pydantic AI
Use Portkey with PydanticAI to take your AI Agents to production
Introduction
PydanticAI is a Python agent framework designed to make it less painful to build production-grade applications with Generative AI. It brings the same ergonomic design and developer experience to GenAI that FastAPI brought to web development.
Portkey enhances PydanticAI with production-readiness features, turning your experimental agents into robust systems by providing:
- Complete observability of every agent step, tool use, and interaction
- Built-in reliability with fallbacks, retries, and load balancing
- Cost tracking and optimization to manage your AI spend
- Access to 200+ LLMs through a single integration
- Guardrails to keep agent behavior safe and compliant
- Version-controlled prompts for consistent agent performance
PydanticAI Official Documentation
Learn more about PydanticAI’s core concepts and features
Installation & Setup
Install the required packages
Generate API Key
Create a Portkey API key with optional budget/rate limits from the Portkey dashboard. You can attach configurations for reliability, caching, and more to this key.
Configure Portkey Client
For a simple setup, first configure the Portkey client that will be used with PydanticAI:
What are Virtual Keys? Virtual keys in Portkey securely store your LLM provider API keys (OpenAI, Anthropic, etc.) in an encrypted vault. They allow for easier key rotation and budget management. Learn more about virtual keys here.
Connect to PydanticAI
After setting up your Portkey client, you can integrate it with PydanticAI by connecting it to a model provider:
Basic Agent Implementation
Let’s create a simple structured output agent with PydanticAI and Portkey. This agent will respond to a query about Formula 1 and return structured data:
The output will be a structured F1GrandPrix
object with all fields properly typed and validated:
You can also use the synchronous API if preferred:
Advanced Features
Working with Images
PydanticAI supports multimodal inputs including images. Here’s how to use Portkey with a vision model:
Visit your Portkey dashboard to see detailed logs of this image analysis request, including token usage and costs.
Tools and Tool Calls
PydanticAI provides a powerful tools system that integrates seamlessly with Portkey. Here’s how to create an agent with tools:
Portkey logs each tool call separately, allowing you to analyze the full execution path of your agent, including both LLM calls and tool invocations.
Multi-agent Applications
PydanticAI excels at creating multi-agent systems where agents can call each other. Here’s how to integrate Portkey with a multi-agent setup:
This multi-agent system uses three specialized agents:
search_agent
- Orchestrates the flow and validates flight selections
extraction_agent
- Extracts structured flight data from raw text
seat_preference_agent
- Interprets user’s seat preferences
With Portkey integration, you get:
- Unified tracing across all three agents
- Token and cost tracking for the entire workflow
- Ability to set usage limits across the entire system
- Observability of both AI and human interaction points
Here’s a diagram of how these agents interact:
Portkey preserves all the type safety of PydanticAI while adding production monitoring and reliability.
Production Features
1. Enhanced Observability
Portkey provides comprehensive observability for your PydanticAI agents, helping you understand exactly what’s happening during each execution.
Traces provide a hierarchical view of your agent’s execution, showing the sequence of LLM calls, tool invocations, and state transitions.
Traces provide a hierarchical view of your agent’s execution, showing the sequence of LLM calls, tool invocations, and state transitions.
Portkey logs every interaction with LLMs, including:
- Complete request and response payloads
- Latency and token usage metrics
- Cost calculations
- Tool calls and function executions
All logs can be filtered by metadata, trace IDs, models, and more, making it easy to debug specific agent runs.
Portkey provides built-in dashboards that help you:
- Track cost and token usage across all agent runs
- Analyze performance metrics like latency and success rates
- Identify bottlenecks in your agent workflows
- Compare different agent configurations and LLMs
You can filter and segment all metrics by custom metadata to analyze specific agent types, user groups, or use cases.
Add custom metadata to your PydanticAI agent calls to enable powerful filtering and segmentation:
This metadata can be used to filter logs, traces, and metrics on the Portkey dashboard, allowing you to analyze specific agent runs, users, or environments.
2. Reliability - Keep Your Agents Running Smoothly
When running agents in production, things can go wrong - API rate limits, network issues, or provider outages. Portkey’s reliability features ensure your agents keep running smoothly even when problems occur.
It’s simple to enable fallback in your PydanticAI agents by using a Portkey Config:
This configuration will automatically try Claude if the GPT-4o request fails, ensuring your agent can continue operating.
Automatic Retries
Handles temporary failures automatically. If an LLM call fails, Portkey will retry the same request for the specified number of times - perfect for rate limits or network blips.
Request Timeouts
Prevent your agents from hanging. Set timeouts to ensure you get responses (or can fail gracefully) within your required timeframes.
Conditional Routing
Send different requests to different providers. Route complex reasoning to GPT-4, creative tasks to Claude, and quick responses to Gemini based on your needs.
Fallbacks
Keep running even if your primary provider fails. Automatically switch to backup providers to maintain availability.
Load Balancing
Spread requests across multiple API keys or providers. Great for high-volume agent operations and staying within rate limits.
3. Prompting in PydanticAI
Portkey’s Prompt Engineering Studio helps you create, manage, and optimize the prompts used in your PydanticAI agents. Instead of hardcoding prompts or instructions, use Portkey’s prompt rendering API to dynamically fetch and apply your versioned prompts.
Manage prompts in Portkey's Prompt Library
Prompt Playground is a place to compare, test and deploy perfect prompts for your AI application. It’s where you experiment with different models, test variables, compare outputs, and refine your prompt engineering strategy before deploying to production. It allows you to:
- Iteratively develop prompts before using them in your agents
- Test prompts with different variables and models
- Compare outputs between different prompt versions
- Collaborate with team members on prompt development
This visual environment makes it easier to craft effective prompts for each step in your PydanticAI agent’s workflow.
Prompt Playground is a place to compare, test and deploy perfect prompts for your AI application. It’s where you experiment with different models, test variables, compare outputs, and refine your prompt engineering strategy before deploying to production. It allows you to:
- Iteratively develop prompts before using them in your agents
- Test prompts with different variables and models
- Compare outputs between different prompt versions
- Collaborate with team members on prompt development
This visual environment makes it easier to craft effective prompts for each step in your PydanticAI agent’s workflow.
The Prompt Render API retrieves your prompt templates with all parameters configured:
You can:
- Create multiple versions of the same prompt
- Compare performance between versions
- Roll back to previous versions if needed
- Specify which version to use in your code:
Portkey prompts use Mustache-style templating for easy variable substitution:
When rendering, simply pass the variables:
Prompt Engineering Studio
Learn more about Portkey’s prompt management features
4. Guardrails for Safe Agents
Guardrails ensure your PydanticAI agents operate safely and respond appropriately in all situations.
Why Use Guardrails?
PydanticAI agents can experience various failure modes:
- Generating harmful or inappropriate content
- Leaking sensitive information like PII
- Hallucinating incorrect information
- Generating outputs in incorrect formats
While PydanticAI provides type safety for outputs, Portkey’s guardrails add additional protections for both inputs and outputs.
Implementing Guardrails
Portkey’s guardrails can:
- Detect and redact PII in both inputs and outputs
- Filter harmful or inappropriate content
- Validate response formats against schemas
- Check for hallucinations against ground truth
- Apply custom business logic and rules
Learn More About Guardrails
Explore Portkey’s guardrail features to enhance agent safety
5. User Tracking with Metadata
Track individual users through your PydanticAI agents using Portkey’s metadata system.
What is Metadata in Portkey?
Metadata allows you to associate custom data with each request, enabling filtering, segmentation, and analytics. The special _user
field is specifically designed for user tracking.
Filter Analytics by User
With metadata in place, you can filter analytics by user and analyze performance metrics on a per-user basis:
Filter analytics by user
This enables:
- Per-user cost tracking and budgeting
- Personalized user analytics
- Team or organization-level metrics
- Environment-specific monitoring (staging vs. production)
Learn More About Metadata
Explore how to use custom metadata to enhance your analytics
6. Caching for Efficient Agents
Implement caching to make your PydanticAI agents more efficient and cost-effective:
Simple caching performs exact matches on input prompts, caching identical requests to avoid redundant model executions.
Simple caching performs exact matches on input prompts, caching identical requests to avoid redundant model executions.
Semantic caching considers the contextual similarity between input requests, caching responses for semantically similar inputs.
7. Model Interoperability
PydanticAI supports multiple LLM providers, and Portkey extends this capability by providing access to over 200 LLMs through a unified interface. You can easily switch between different models without changing your core agent logic:
Portkey provides access to LLMs from providers including:
- OpenAI (GPT-4o, GPT-4 Turbo, etc.)
- Anthropic (Claude 3.5 Sonnet, Claude 3 Opus, etc.)
- Mistral AI (Mistral Large, Mistral Medium, etc.)
- Google Vertex AI (Gemini 1.5 Pro, etc.)
- Cohere (Command, Command-R, etc.)
- AWS Bedrock (Claude, Titan, etc.)
- Local/Private Models
Supported Providers
See the full list of LLM providers supported by Portkey
Set Up Enterprise Governance for PydanticAI
Why Enterprise Governance? If you are using PydanticAI inside your organization, you need to consider several governance aspects:
- Cost Management: Controlling and tracking AI spending across teams
- Access Control: Managing which teams can use specific models
- Usage Analytics: Understanding how AI is being used across the organization
- Security & Compliance: Maintaining enterprise security standards
- Reliability: Ensuring consistent service across all users
Portkey adds a comprehensive governance layer to address these enterprise needs. Let’s implement these controls step by step.
Create Virtual Key
Virtual Keys are Portkey’s secure way to manage your LLM provider API keys. They provide essential controls like:
- Budget limits for API usage
- Rate limiting capabilities
- Secure API key storage
To create a virtual key: Go to Virtual Keys in the Portkey App. Save and copy the virtual key ID
Save your virtual key ID - you’ll need it for the next step.
Create Default Config
Configs in Portkey define how your requests are routed, with features like advanced routing, fallbacks, and retries.
To create your config:
- Go to Configs in Portkey dashboard
- Create new config with:
- Save and note the Config name for the next step
Configure Portkey API Key
Now create a Portkey API key and attach the config you created in Step 2:
- Go to API Keys in Portkey and Create new API key
- Select your config from
Step 2
- Generate and save your API key
Connect to PydanticAI
After setting up your Portkey API key with the attached config, connect it to your PydanticAI agents:
Enterprise Features Now Available
Your PydanticAI integration now has:
- Departmental budget controls
- Model access governance
- Usage tracking & attribution
- Security guardrails
- Reliability features