Best Mastra Alternatives

The most widely-used framework for building LLM-powered applications, available in Python and JavaScript. Provides abstractions for chains, agents, RAG, memory, tool usage, and structured output. Integrates with 100+ LLM providers, vector stores, document loaders, and tools. LangSmith offers tracing and evaluation. LangGraph enables stateful, multi-agent workflows with cycles. 100K+ GitHub stars. The de facto standard for LLM application development despite growing alternatives like LlamaIndex.

Leading Python framework for building LLM-powered applications with focus on data-aware and agentic workflows. Provides tools for RAG (Retrieval-Augmented Generation), document indexing, vector store integrations, query engines, and multi-agent orchestration. 150+ data connectors for various sources. Works with OpenAI, Anthropic, local models, and more. Includes LlamaHub for community tools and LlamaCloud for managed RAG pipelines. 50K+ GitHub stars.

Open-source TypeScript toolkit by Vercel for building AI-powered apps with streaming chat UIs, structured outputs, tool calling, and agent workflows. Framework-agnostic core with integrations for React, Next.js, Svelte, Vue, and Nuxt. Supports a broad AI SDK v6 provider catalog including OpenAI, Anthropic, Google, xAI, Mistral, Bedrock, Groq, and OpenAI-compatible providers. Includes useChat and useCompletion hooks for rapid UI development. The standard SDK for adding AI features to web apps.

assistant-ui is a TypeScript/React component library for building AI chat interfaces with streaming responses, tool rendering, branching conversations, and LLM provider integrations. It supports Vercel AI SDK, LangGraph, and custom backends out of the box. Used by LangChain, Browser Use, and Stack AI. YC W25-backed with 9,000+ GitHub stars and 450K+ monthly npm downloads.

VoltAgent is an open-source TypeScript AI agent framework with built-in observability, RAG support, memory management, and MCP integration. It provides a structured approach to building production AI agents in the Node.js ecosystem with agent debugging tools, sub-agent orchestration, and tool management. Over 7,000 GitHub stars and 150K+ weekly npm downloads.

Cloudflare Agents is an open-source SDK for building and deploying AI agents that run on Cloudflare's global edge network. It provides durable state, scheduled tasks, WebSocket communication, and browser rendering capabilities within Workers. Agents persist across requests using Durable Objects and can orchestrate multi-step workflows with built-in MCP server support. Over 7,000 GitHub stars.