Sim

What is Sim?

Sim is an open source platform for building, deploying, and monitoring AI agents and automation workflows on a visual canvas. You drag blocks — triggers, models, tools, and data — onto a React Flow canvas, wire them together, and ship an agent that can act across 1,000+ integrations and any major LLM. You can build visually, describe what you want in natural language, or drop into code.

What is Sim best for?

Teams that want Zapier-style automation but with LLMs and AI agents at the center — routing support tickets, enriching CRM records, or running research agents that read a knowledge base and take action. It suits builders who want a visual canvas plus real-time run logs, and who value a strong self-host story with support for local models via Ollama or vLLM.

What can Sim do?

• Build agents visually, conversationally with a copilot, or in code on a React Flow canvas
• Connect 1,000+ integrations — Slack, Notion, HubSpot, Salesforce, Gmail, and more
• Use every major LLM provider, or run local models through Ollama and vLLM
• Add knowledge bases with vector search for RAG over your own documents
• Store structured data in built-in tables and ingest files without external services
• Monitor runs, logs, and schedules with full execution visibility
• Self-host with Docker and PostgreSQL, or use the managed cloud at sim.ai

Where does Sim fall short?

• It’s a young, fast-moving project — the product has already rebranded from “Sim Studio” and reshaped its feature set, so expect churn in the UI, docs, and APIs as it matures.
• The AI-agent focus makes it heavier than a plain integration tool. If you just need to move data between two apps on a schedule with no LLM in the loop, a leaner automation tool like n8n or Activepieces is a simpler fit.
• Advanced cloud features — SSO, SOC2, and official self-hosting support — sit behind the Enterprise plan, so managed teams needing those pay for a custom contract.

Is Sim free?

Yes — Sim is Apache-2.0 licensed and free to self-host, so you only pay for your own server and whatever LLM API usage your agents consume. The managed Sim cloud has a free tier (1,000 one-time credits, 1 workspace, 10 concurrent executions), then Pro at $25/user/month and Max at $100/user/month, with custom Enterprise pricing for SSO and dedicated support.

What does Sim replace?

Sim is a self-hosted, AI-native alternative to Zapier, Make, and Microsoft Power Automate. It does the same connect-your-apps-and-automate job, but centers workflows on LLMs and agents, and lets you run everything on your own infrastructure without per-task cloud pricing.

FAQ

Is Sim open source? Yes. Sim is released under the Apache License 2.0 — a permissive OSI-approved license — and the full source is on GitHub, free to self-host and modify.

Can I self-host Sim for free? Yes. Self-hosting is free; you only pay for the server plus any LLM API calls your agents make. The npx simstudio setup wizard provisions a Docker Compose stack for you.

Is Sim a good Zapier alternative? For teams building AI-driven automation, yes — it puts agents and LLMs at the core and can run on your own infrastructure. For simple, LLM-free app-to-app automation, a lighter tool may be easier.

What do I need to run Sim? A server with Docker and PostgreSQL, plus Node.js 20+ and Bun for local development. For AI features you supply LLM API keys, or run local models with Ollama or vLLM.