A local, browser-based simulator for developing and testing Slack apps and bots
Develop and test your Slack applications end-to-end without installing them into a real workspace. Run entirely offline with full control over your test environment.
Get Started
No ngrok, no OAuth dance, no network dependencies. Just run
yarn dev and start developing against it immediately.
Switch between mock users instantly to test multi-user conversations and bot interactions from any perspective.
Wipe your workspace back to a clean seed state with one click. Perfect for reproducible testing and scenario scripting.
SQLite-backed persistence keeps your workspace state across sessions. Reset anytime to start fresh.
Work on planes, trains, or customer sites without internet. Your development environment travels with you.
Inspect Events, Interactivity payloads, and Web API calls in real-time. Built-in logs and database inspector included.
^ Limited support - some advanced Block Kit features may not be fully implemented
† Specific events implemented - pin, unpin, channel archive, member join, etc.
