Overview
Bumblebee is a desktop automation runtime whose input doesn't look robotic. Conventional automation moves the cursor in straight lines at constant velocity and types at a fixed cadence — trivially detectable, and useless for testing how software behaves under real human interaction. Bumblebee models the human instead.
It exists for three workloads: accessibility tooling that acts on a user's behalf, QA suites that need realistic interaction patterns, and agentic workflows where an AI operates a real UI.
How it works
- Trajectory generation. Cursor paths are predicted rather than interpolated — curved approaches, overshoot-and-correct behavior near targets, and speed profiles that follow human motor patterns (fast mid-path, decelerating on approach). Adaptive noise keeps no two movements identical.
- Keystroke modeling. Typing is generated with human-style inter-key delays: bursts on common bigrams, pauses at punctuation and word boundaries, and variable rhythm across a session rather than a single sampled distribution.
- Runtime layer. A policy-driven executor sits between high-level intents ("click the submit button", "fill this form") and low-level OS input events, so callers describe what to do and the runtime decides how it should physically look.
Key decisions
Model behavior, not just output. Early versions sampled from static timing distributions; they looked fine in isolation and wrong in aggregate. Moving to learned, context-dependent behavior fixed session-level realism — the metric that actually matters for QA fidelity.
Intents as the API. Exposing high-level actions instead of raw move/click primitives keeps automation scripts readable and lets the realism layer improve without breaking callers.
Safety rails by default. The runtime enforces bounding regions, rate limits, and an always-available kill switch — automation that controls a real desktop must fail conservatively.
Status
Actively developed. Trajectory and keystroke engines are stable; current work extends the intent vocabulary and screen-understanding integration for agentic use.