PydanticAI

PydanticAISince 2026-02

PydanticAI is a lightweight, production-grade Python agent framework created by the core Pydantic team. It brings strict type validation, structured outputs, and clean dependency injection to generative AI development, ensuring models strictly adhere to domain schemas.

Designed to eliminate messy string parsing and unreliable tool outputs, PydanticAI treats LLM interactions as type-checked functions. It supports model agnosticism across OpenAI, Anthropic, Gemini, and Ollama, offering native telemetry via OpenTelemetry and seamless integration with Logfire.

SmolagentsSince 2026-01

Smolagents is an ultra-lightweight, code-first Python framework created by Hugging Face for building, orchestrating, and executing autonomous AI agents in minimal lines of code. Rejecting the bloated, multi-layered abstractions of legacy agent libraries, Smolagents emphasizes 'Code Agents'—agents that express their reasoning and tool actions directly in executable Python code rather than rigid JSON string payloads. By letting LLMs write executable Python logic, Smolagents achieves vastly superior composability for data manipulation, mathematical operations, and complex loops while cutting prompt token overhead by up to 30%.

Smolagents natively supports both local open-source models (via Hugging Face Transformers and Ollama) and commercial frontier models (via LiteLLM, OpenAI, and Anthropic APIs). It includes pre-built modules for secure sandboxed Python execution, multi-modal web browsing agents with visual comprehension, and seamless sharing of agent tools directly on the Hugging Face Hub. The framework is fully modality-agnostic, supporting text, speech, vision, and custom API tools with zero vendor lock-in.