Backlot

Backlot runs local emulators of enterprise SaaS APIs: Slack, Gmail, Google Drive, GitHub, Jira, Notion and S3. It reproduces the real response shapes, pagination, authentication and per-document access controls over a deterministic corpus you control.

Why it matters: Connecting a real Slack app means creating a workspace, registering the app, picking OAuth scopes and waiting on an admin. With Backlot it is pip install, backlot serve, and one changed base URL. Your integration tests run with no vendor account, no secrets in CI and no network.

Point an official SDK at http://127.0.0.1:8000 and the same code that targets Slack in production talks to Backlot in development. MIT licensed, about 280 stars.