The best sim alternatives

FastGPT

labring/FastGPT

FastGPT is a knowledge-based platform built on the LLMs, offers a comprehensive suite of out-of-the-box capabilities such as data processing, RAG retrieval, and visual AI workflow orchestration, letting you easily develop and deploy complex question-answering systems without the need for extensive setup or configuration.

Choose FastGPT if…

• you specifically need agent or claude

Shares deepseek, nextjs, openai, rag with sim.

dify

langgenius/dify

Build Agentic workflows, RAG pipelines, with rich AI model and tool support on one collaborative workspace. Deploy on cloud, VPC, or self-hosted, so teams move from prototype to production without rebuilding the stack.

Choose dify if…

• you want something your agent can install directly rather than a library to wire up yourself
• you want the more widely starred option (160.3k)
• you specifically need agent or agentic-ai

Shares agentic-workflow, ai, automation, deepseek with sim.

CopilotKit

CopilotKit/CopilotKit

The Frontend Stack for Agents & Generative UI. React, Angular, Mobile, Slack, and more. Makers of the AG-UI Protocol

Choose CopilotKit if…

• MIT License suits your use better than Apache License 2.0
• you specifically need agent or agent-native

Shares agents, ai, nextjs, react with sim.

Kun

KunAgent/Kun

Local-first AI agent workspace for coding, writing, design, research, and automation — one runtime for desktop GUI and TUI.

Choose Kun if…

• you prefer a smaller, narrower project to a large one
• you specifically need ai-agent or ai-assistant

Shares agentic-workflow, automation, deepseek, react with sim.

coze-studio

coze-dev/coze-studio

An AI agent development platform with all-in-one visual tools, simplifying agent creation, debugging, and deployment like never before. Coze your way to AI Agent creation.

Choose coze-studio if…

• you want something your agent can install directly rather than a library to wire up yourself
• you specifically need agent or agent-platform

Shares chatbot, no-code, rag, typescript with sim.

dyad

dyad-sh/dyad

Local, open-source AI app builder for power users ✨ v0 / Lovable / Replit / Bolt alternative 🌟 Star if you like it!

Choose dyad if…

• you specifically need ai-app-builder or bolt

Shares anthropic, artificial-intelligence, deepseek, gemini with sim.

easy-vibe

datawhalechina/easy-vibe

💻 vibe coding 101｜The first course for AI-native product builders.

Choose easy-vibe if…

• you would rather work in JavaScript than TypeScript
• you specifically need agent or coding

Shares ai, deepseek, gemini, low-code with sim.

leon

leon-ai/leon

🧠 Leon is your open-source personal assistant.

Choose leon if…

• MIT License suits your use better than Apache License 2.0
• you specifically need ai-agent or ai-assistant

Shares ai, artificial-intelligence, automation, chatbot with sim.

LobsterAI

netease-youdao/LobsterAI

Open-source, desktop-grade AI agent that gets real work done — data analysis, slides, docs, video & web research. Built on OpenClaw; runs tools on your real desktop and takes commands from your phone via WeChat, Feishu, DingTalk & Telegram.

Choose LobsterAI if…

• MIT License suits your use better than Apache License 2.0
• you prefer a smaller, narrower project to a large one
• you specifically need agent or ai-agent

Shares automation, chatbot, react with sim.

lobehub

lobehub/lobehub

🤯 LobeHub is your Chief Agent Operator, organizing your agents into 7×24 operations by hiring, scheduling, and reporting on your entire AI team.

Choose lobehub if…

• you want something your agent can install directly rather than a library to wire up yourself
• you want the more widely starred option (83.8k)
• you specifically need agent or agent-collaboration

Shares ai, deepseek, gemini, openai with sim.

ai-website-cloner-template

JCodesMore/ai-website-cloner-template

Clone any website with one command using AI coding agents

Choose ai-website-cloner-template if…

• you would rather work in JavaScript than TypeScript
• MIT License suits your use better than Apache License 2.0
• you want something your agent can install directly rather than a library to wire up yourself
• you specifically need ai-agents or ai-tools

Shares ai, automation, nextjs, react with sim.

mastra

mastra-ai/mastra

Mastra is the modern TypeScript framework for AI-powered applications and agents.

Choose mastra if…

• you specifically need chatbots or evals

Shares agents, ai, nextjs, typescript with sim.