Pydantic-DeepAgents: A Lightweight, Production-Ready Framework for Building Autonomous AI Agents

Published: (December 21, 2025 at 08:19 PM EST)
2 min read
Source: Dev.to

Source: Dev.to

Overview

Inspired by LangChain deepagents — but simpler, type‑safe, and with Docker sandboxing built‑in.

In 2025, autonomous AI agents are no longer just research prototypes — they power real‑world automation, code generation tools, data pipelines, and intelligent assistants. Many popular agent frameworks, however, have heavy dependencies, complex graphs, and steep learning curves that make production deployment challenging.

Pydantic‑DeepAgents is a minimal yet powerful open‑source framework that extends Pydantic‑AI with everything needed to create reliable, production‑grade agents.

GitHub repository:

We were heavily inspired by LangChain’s deepagents project — a clean implementation of “deep agent” patterns such as planning loops, tool calling, sub‑agent delegation, and human‑in‑the‑loop workflows. Instead of reinventing the wheel, we asked: What if we built the same powerful patterns, but fully in the Pydantic‑AI ecosystem? The result is a framework that:

  • Keeps dependencies lightweight (no LangGraph, no massive ecosystem)
  • Leverages Pydantic’s native type‑safety and validation for structured outputs
  • Adds production‑focused features missing from many alternatives

Key Features

CategoryCapabilities
Planning & ReasoningTodoToolset for autonomous task breakdown and self‑correction
Filesystem AccessFull read/write operations with FilesystemToolset
Sub‑agent DelegationBreak complex tasks into specialized sub‑agents (SubAgentToolset)
Extensible Skills SystemDefine new agent capabilities with simple Markdown prompts (ideal for rapid iteration)
Multiple BackendsIn‑memory, persistent filesystem, secure DockerSandbox (isolated code execution), and CompositeBackend
File UploadsSeamless processing via run_with_files() or deps.upload_file()
Context ManagementAutomatic summarization for long‑running conversations
Human‑in‑the‑LoopBuilt‑in confirmation workflows for critical actions
Streaming SupportToken‑by‑token responses for responsive UIs
Structured OutputsType‑safe Pydantic models via output_type

Demo Application

A complete full‑stack demo (FastAPI backend + streaming web UI) showcases:

  • Live agent reasoning traces
  • File uploads and processing
  • Human approval steps
  • Streaming responses

Demo repository:
Quick video walkthrough:

When to Choose Pydantic‑DeepAgents

  • You need a clean, maintainable agent architecture without framework bloat.
  • Strong guarantees around data validation and structured responses are required.
  • Secure execution (Docker sandbox) is a must out of the box.
  • Fast prototyping with Markdown‑defined skills is desirable.
  • Easy deployment in production environments is a priority.

It’s especially suitable if you’re already using Pydantic‑AI, prefer minimalism, or need agents that interact safely with files and external tools.

Installation

pip install pydantic-deep

Contributing

Check out the repository, star it if you find it useful, and feel free to open issues or pull requests — contributions are welcome!

Repository:

Team at Vstorm

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