The SFTP/SSH download routes buffered a remote file into memory with the only size guard being sftp.stat().size — a value the caller-supplied SSH server controls. A server that reports a tiny size and then streams endlessly drove unbounded heap growth until OOM. Read through the existing readNodeStreamToBufferWithLimit limiter, which enforces the cap on bytes actually received and destroys the stream on breach, via a small readSftpFileCapped wrapper in sftp/utils. All four SFTP-reading tool routes now share it — download, download-file, read-file-content, and the append path of write-file-content, which had no cap at all. The wrapper keeps a no-op error listener on the stream for its whole life: ssh2 rejects still-pending SFTP requests when the channel closes, which arrives as a late error event after the limiter has detached its own handlers, and an error event with no listener would take the process down. Too-large responses now return 413 to match how the rest of the routes surface PayloadSizeLimitError, and responses report the actual byte count rather than the server-reported stat size.
A workspace to build, deploy and manage AI agents and workflows.
Quickstart
Cloud-hosted: sim.ai
Self-hosted
git clone https://github.com/simstudioai/sim.git && cd sim
bun run setup
Capabilities
- Connect 1,000+ integrations and every major LLM
- Add Slack, Notion, HubSpot, Salesforce, databases, and more
- Build agents visually, conversationally, or with code
- Ingest files, knowledge bases, and structured table data
- Monitor runs, logs, schedules, and workflow activity
One workspace, every surface
Chat and workflows are just the start — tables, files, knowledge, and scheduled tasks all live in the same workspace.
Tables — a database, built in |
Files — one store for your team and every agent |
Knowledge — your agents' memory |
Scheduled tasks — runs on your schedule |
Self-hosting
bun run setup is an interactive wizard: it provisions the database, generates secrets, writes your .env files, connects a Chat API key, and starts Sim the way you choose:
- Local dev — run from source to contribute or hack on Sim
- Docker Compose — a self-contained instance for testing self-hosting
- Kubernetes (Helm) — deploy to a local cluster
When it finishes, open http://localhost:3000.
Manage your install with bun run sim:
bun run sim start | stop | restart # bring your install up / down / cycle
bun run sim status # what's installed and healthy
bun run sim logs # follow logs
bun run sim doctor # diagnose configuration problems
bun run sim down # remove containers (data kept)
bun run sim reset # archive .env and wipe managed data
sim detects how you're running (Docker Compose, local dev, or Kubernetes) and acts accordingly.
Prefer a bare sim? Run bun link once — but note sim lands in ~/.bun/bin, which Homebrew's bun doesn't add to your PATH, so you may need export PATH="$HOME/.bun/bin:$PATH" in your shell profile.
Sim also supports local models via Ollama and vLLM. See the self-hosting docs for details.
Chat API Keys
Chat is a Sim-managed service. bun run setup connects a Chat API key for you — sign in when it opens your browser and the key is stored automatically. To view, create, or revoke keys later, go to sim.ai/selfhost/settings/chat-keys.
Environment Variables
See the environment variables reference for the full list, or apps/sim/.env.example for defaults.
Tech Stack
Next.js · Bun · PostgreSQL · Drizzle · Better Auth · Tailwind — and the rest of the stack
- Framework: Next.js (App Router)
- Runtime: Bun
- Database: PostgreSQL with Drizzle ORM
- Authentication: Better Auth
- Schema Validation: Zod
- UI: Shadcn, Tailwind CSS
- Streaming Markdown: Streamdown
- State Management: Zustand, TanStack Query
- Flow Editor: ReactFlow
- Docs: Fumadocs
- Monorepo: Turborepo
- Realtime: Socket.io
- Background Jobs: Trigger.dev
- Remote Code Execution: E2B
- Isolated Code Execution: isolated-vm
Contributing
We welcome contributions! Please see our Contributing Guide for details.
License
This project is licensed under the Apache License 2.0 - see the LICENSE file for details.





