Theodore Li 76ad59fd7d fix(stream): Avoid bun memory leak bug from TransformStream (#4255)
* Avoid bun memory leak bug from TransformStream

* fix(executor): skip content persistence when stream consumer exits early

Previously, if the onStream consumer caught an internal error without
re-throwing, the block-executor would treat the shortened accumulator
as the complete response, persist a truncated string to memory via
appendToMemory, and set it as executionOutput.content.

Track whether the source ReadableStream actually closed (done=true) in
the pull handler. If onStream returns before the source drains, skip
content persistence and log a warning — the old tee()-based flow was
immune to this because the executor branch drained independently of
the client branch.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* fix lint

* fix(executor): early-return when no streamed content to make onFullContent symmetric

Previously, executionOutput.content was guarded by `if (fullContent)`
but `onFullContent` fired regardless. The agent-handler implementor
defensively bails on empty/whitespace content, but that's a callee
contract, not enforced at the call site — future implementors could
spuriously persist empty assistant turns to memory.

Hoist the `!fullContent` check to a single early return, so both the
output write and the callback share the same precondition.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-27 14:23:36 -04:00

Sim Logo

The open-source platform to build AI agents and run your agentic workforce. Connect 1,000+ integrations and LLMs to orchestrate agentic workflows.

Sim.ai Discord Twitter Documentation

Ask DeepWiki Set Up with Cursor

Build Workflows with Ease

Design agent workflows visually on a canvas—connect agents, tools, and blocks, then run them instantly.

Workflow Builder Demo

Supercharge with Copilot

Leverage Copilot to generate nodes, fix errors, and iterate on flows directly from natural language.

Copilot Demo

Integrate Vector Databases

Upload documents to a vector store and let agents answer questions grounded in your specific content.

Knowledge Uploads and Retrieval Demo

Quickstart

Cloud-hosted: sim.ai

Sim.ai

Self-hosted: NPM Package

npx simstudio

http://localhost:3000

Note

Docker must be installed and running on your machine.

Options

Flag Description
-p, --port <port> Port to run Sim on (default 3000)
--no-pull Skip pulling latest Docker images

Self-hosted: Docker Compose

git clone https://github.com/simstudioai/sim.git && cd sim
docker compose -f docker-compose.prod.yml up -d

Open http://localhost:3000

Sim also supports local models via Ollama and vLLM — see the Docker self-hosting docs for setup details.

Self-hosted: Manual Setup

Requirements: Bun, Node.js v20+, PostgreSQL 12+ with pgvector

  1. Clone and install:
git clone https://github.com/simstudioai/sim.git
cd sim
bun install
bun run prepare  # Set up pre-commit hooks
  1. Set up PostgreSQL with pgvector:
docker run --name simstudio-db -e POSTGRES_PASSWORD=your_password -e POSTGRES_DB=simstudio -p 5432:5432 -d pgvector/pgvector:pg17

Or install manually via the pgvector guide.

  1. Configure environment:
cp apps/sim/.env.example apps/sim/.env
# Create your secrets
perl -i -pe "s/your_encryption_key/$(openssl rand -hex 32)/" apps/sim/.env
perl -i -pe "s/your_internal_api_secret/$(openssl rand -hex 32)/" apps/sim/.env
perl -i -pe "s/your_api_encryption_key/$(openssl rand -hex 32)/" apps/sim/.env
# DB configs for migration
cp packages/db/.env.example packages/db/.env
# Edit both .env files to set DATABASE_URL="postgresql://postgres:your_password@localhost:5432/simstudio"
  1. Run migrations:
cd packages/db && bun run db:migrate
  1. Start development servers:
bun run dev:full  # Starts Next.js app and realtime socket server

Or run separately: bun run dev (Next.js) and cd apps/sim && bun run dev:sockets (realtime).

Copilot API Keys

Copilot is a Sim-managed service. To use Copilot on a self-hosted instance:

  • Go to https://sim.ai → Settings → Copilot and generate a Copilot API key
  • Set COPILOT_API_KEY environment variable in your self-hosted apps/sim/.env file to that value

Environment Variables

See the environment variables reference for the full list, or apps/sim/.env.example for defaults.

Tech 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.

Made with ❤️ by the Sim Team

Description
No description provided
Readme Apache-2.0 628 MiB
Languages
TypeScript 70.8%
MDX 26.1%
JavaScript 2.7%
CSS 0.2%