* fix(providers): stop the final regenerated stream from re-calling tools and clobbering the answer
After the silent tool loop settles, OpenAI Responses and Gemini re-issue a
streaming request purely to stream the answer as prose — but with tools still
attached and auto tool choice, a reasoning model can re-decide to call a tool
there. Streamed calls are never executed on this path, so the run ends with a
dead function call, an empty streamed answer, and the stream callback
clobbering the tool loop's settled text with '' (deployed chat rendered
{"content": ""}).
Force tool_choice 'none' / functionCallingConfig NONE on the regeneration and
keep the tool loop's settled answer whenever the stream ends without text.
* feat(openai): settled tool chips on the regenerated answer stream
The silent Responses tool loop has no live stream while tools run, so opted-in
consumers saw no tool chips at all for OpenAI. The loop now records each
executed call and prepends settled tool_call_start/end pairs (name + status
only) to the agent-events stream ahead of the regenerated answer. Runs without
a sink never see these events, so legacy output is unchanged.
* fix(providers): apply the regeneration guard fleet-wide
Audit of every silent tool loop for the same race fixed for OpenAI/Gemini
(final regenerated stream re-calls a tool that is never executed, ending with
an empty answer that clobbers the settled text):
- anthropic (both implementations): tool_choice {type:'none'} on the
regeneration (tools must stay — history carries tool_use blocks) + keep the
settled answer when the stream ends without text
- groq: was re-applying the ORIGINAL tool_choice, so forced-tool runs
re-forced the tool on the regeneration — guaranteed dead call; now 'none'
+ fallback
- deepseek, mistral, cerebras, azure-openai (legacy chat path), openrouter,
xai: 'auto' -> 'none' + fallback
- bedrock: fallback only — Bedrock's ToolChoice has no 'none' and toolConfig
is required when history carries toolUse blocks
Already guarded (no change): meta, sakana, nvidia, vllm, litellm, baseten,
together, fireworks, kimi, zai, ollama.
A workspace to build, deploy and manage AI agents and workflows.
Quickstart
Cloud-hosted: sim.ai
Self-hosted
npx simstudio
Docker must be installed and running. Use -p, --port <port> to run Sim on a different port, or --no-pull to skip pulling the latest Docker images.
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
Docker Compose
git clone https://github.com/simstudioai/sim.git && cd sim
docker compose -f docker-compose.prod.yml up -d
Sim also supports local models via Ollama and vLLM. See the Docker self-hosting docs for setup details.
Manual Setup
Requirements: Bun, Node.js v20+, PostgreSQL 12+ with pgvector
- Clone and install:
git clone https://github.com/simstudioai/sim.git
cd sim
bun install
bun run prepare # Set up pre-commit hooks
- 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.
- 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"
- Run migrations:
cd packages/db && bun run db:migrate
- 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).
Chat API Keys
Chat is a Sim-managed service. To use Chat on a self-hosted instance:
- Go to https://sim.ai → Settings → Chat keys and generate a Chat API key
- Set
COPILOT_API_KEYenvironment 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
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.





