Best Mastra Alternatives in 2026

Genkit is Google's open-source AI framework for TypeScript, Go, and Python developers. It provides typed flows, RAG, tool calling, and multi-agent support with a standout local Developer UI for iterating prompts and debugging traces. Free under Apache 2.0.

OpenAI's official open-source framework for multi-agent workflows. Launched March 2025 as the production successor to Swarm. Provides handoffs, guardrails, tracing, and voice agent support in Python and TypeScript.

Vercel AI SDK is an open-source TypeScript toolkit for building AI-powered applications and agents. It provides a unified API across 20+ model providers, streaming UI hooks for React and Vue, structured output with Zod, and a full agent abstraction layer.

PydanticAI is an open-source Python framework for building production-grade AI agents. Created by Samuel Colvin (creator of Pydantic), it brings FastAPI-style type safety, structured outputs, and dependency injection to agent development. Free, MIT-licensed, 16k+ GitHub stars.

Langflow is an open-source visual builder for LLM pipelines, RAG applications, and multi-agent workflows. Created in 2023 and acquired by DataStax in 2024, it lets developers assemble complex AI flows on a canvas and export them as production APIs, no boilerplate required.

Agno is an open-source Python framework for building multi-agent AI systems, rebranded from Phidata in January 2025. Model-agnostic, Apache 2.0, with built-in memory, knowledge bases, and a production-ready AgentOS runtime for deploying agents as services.

Letta is the open-source agent framework from UC Berkeley's MemGPT research team. It gives AI agents persistent, self-editable memory using an OS-inspired three-tier architecture. Apache 2.0 with a cloud-hosted API option.

Haystack is deepset's open-source Python framework for building production-ready RAG pipelines and AI agents. Apache 2.0 licensed, it gives developers explicit control over retrieval, context routing, and generation through composable, YAML-serializable pipeline graphs.

DSPy is a Stanford NLP framework that treats prompt engineering as a compiler problem: you write typed signatures and modules, define a metric, and an optimizer searches for the best prompts automatically. Free, Apache 2.0, 5M+ monthly PyPI downloads.

smolagents is Hugging Face's open-source Python library for building AI agents that write code as actions rather than JSON tool calls. Apache 2.0, ~1,000 lines of core code, supports 100-plus LLMs including local models via Ollama and Transformers.