Waleed 47e8f1eb5b fix(ssh/sftp): cap remote file reads on received bytes, not stat() size (#6168)
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.
2026-08-01 16:53:46 -07:00

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Sim — Integrate, Context, Build, and Monitor AI agents

A workspace to build, deploy and manage AI agents and workflows.

Quickstart

Cloud-hosted: sim.ai

Open sim.ai

Self-hosted

git clone https://github.com/simstudioai/sim.git && cd sim
bun run setup

Open http://localhost:3000

The Sim platform — chat on the left, the visual workflow builder on the right

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 in Sim — structured data your agents can query

Tables — a database, built in

Files in Sim — documents for your team and every agent

Files — one store for your team and every agent

Knowledge bases in Sim — synced docs your agents can search

Knowledge — your agents' memory

Scheduled tasks in Sim — recurring agent runs on a calendar

Scheduled tasks — runs on your schedule

Self-hosting

Requirements: Bun and Docker.

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

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.

Built by the Sim team in San Francisco

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