Waleed 418722559d fix(mcp): bound and tear down one-shot OAuth fetches so auth can't hang (#5789)
The SSRF-guarded fetch used for MCP OAuth (discovery, DCR, token exchange/
refresh, RFC 7009 revocation) created a fresh pinned undici Agent per request
and never tore it down, and returned the live response so the SDK's lazy body
read happened outside any deadline. The MCP SDK sets no timeout on OAuth legs,
so a stalled body read or a leaked keep-alive socket could leave the flow — and
the browser waiting on it — pending indefinitely ("Connecting… forever").

- Buffer the (always-small) OAuth JSON body inside the guard, under the composed
  deadline/caller AbortSignal, then return a detached in-memory Response. undici's
  bodyTimeout only measures idle gaps between chunks and cannot bound a slow-drip
  body; the AbortSignal is the only true wall-clock deadline over the body read.
- Destroy (not close) the per-request pinned Agent on every path so a one-shot
  leg can't strand its keep-alive socket, and teardown itself can't hang.
- Fix the same per-request Agent leak in the auth-type probe.
- Returning a normalized global Response also surfaces provider token-endpoint
  errors cleanly instead of the SDK's opaque parse failure.
2026-07-20 18:55:33 -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

npx simstudio

Open http://localhost:3000

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.

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

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.

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).

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_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

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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