Most AI workflow builders want you on their cloud plan from minute one. Sim is different: it's fully open source under Apache 2.0, you can self-host the entire thing for free, and the visual canvas is genuinely quick to pick up. Here's how to go from nothing to a working agent workflow.
What Sim actually is
Sim is a visual workspace for building, testing, and deploying AI agent workflows, built by founders Emir Karabeg and Waleed Latif with Y Combinator backing. You design workflows on a canvas by connecting agents, tools, and logic blocks, then run them instantly or on a schedule. It connects to more than 1,000 integrations and every major LLM provider, and it supports local models through Ollama if you'd rather not send data to an external API at all.
Step 1: decide cloud or self-hosted
You have two real options:
- **Cloud, at sim.ai** — fastest way to start. The free Community plan comes with 1,000 one-time credits. Paid plans start at $25/month (Pro, 5,000 credits/month) and go up to $100/month (Max, 20,000 credits/month), with a 15% discount for annual billing.
- **Self-hosted** — completely free, runs on your own infrastructure. You'll need Docker, Bun, and PostgreSQL (with the pgvector extension), or you can spin it up with `npx simstudio`, which opens the app at `localhost:3000`.
If you're testing the idea or don't want to manage infrastructure, start on the cloud plan. If you want zero ongoing cost and full control over your data, self-host.
Step 2: install it
For the fastest path, run:
npx simstudioThis pulls down what it needs and opens Sim locally. If you want a more permanent self-hosted setup, Sim also ships Docker Compose configs that bring up the app, a PostgreSQL database with pgvector, and a realtime collaboration server together. Either route gets you the same canvas.
Step 3: build your first workflow
Once you're in, start simple. A good first project is a document Q&A agent:
- Create a new workflow and drop an agent block on the canvas.
- Connect a knowledge block and upload a document (a PDF, a set of notes, anything you want the agent to answer questions about). Sim stores this in a vector store automatically.
- Add a trigger, either a manual "run" button for testing or a scheduled/webhook trigger for production use.
- Wire the agent block's output to wherever you want the answer to land: a Slack message, an API response, or just the built-in chat panel.
Step 4: use Copilot instead of building everything by hand
Sim's Copilot can generate nodes, fix broken connections, and adjust a flow based on a plain-language description, so you don't have to build every block manually. Typing something like "add a step that summarizes the document before answering" will often get you most of the way to the finished workflow.
Step 5: test, then deploy
Run the workflow manually a few times with different inputs before turning on a schedule or webhook trigger. Sim's real-time execution view shows you exactly which block ran, what it returned, and where a workflow failed, which matters once you're chaining more than two or three steps together.
One independent review of Sim reported building a customer support automation in about 45 minutes that had taken roughly 6 hours to put together in n8n, largely because the visual canvas and pre-built blocks cut out a lot of manual wiring. Your mileage will vary depending on how custom your workflow is, but it's a reasonable illustration of where Sim saves time: straightforward, well-supported integrations, not highly bespoke logic.
Where Sim falls short
Sim is still catching up to more mature platforms like n8n or Latenode on sheer integration count and community-built templates. If you need a very specific, obscure API connection, you may end up writing a custom code block rather than finding a ready-made one. It's also younger as a company, so long-term roadmap and support depth are less proven than incumbents.
Worth trying if
Sim is worth your time if you want a visual, fast way to prototype agent workflows without committing to a subscription first, or if data control matters enough that self-hosting for free is a real requirement rather than a nice-to-have. If you're comparing it against a paid, hosted alternative, see our [Sim vs. Latenode comparison](https://questloops.com/compare/sim-vs-latenode) for how the two stack up on cost and flexibility, and check the full [Sim tool page](https://questloops.com/tools/sim) for the complete feature list.
