Halo Toolkit

What it is

Halo is the embeddable side of experience work: code that has to run inside someone else’s website without breaking it, measure what visitors do, and let non-engineers configure what appears.

Why embeddable is hard

A widget that ships to third-party pages inherits a hostile environment — unknown CSS, competing scripts, unpredictable layout, and a performance budget that belongs to someone else. The runtime therefore isolates styles, defers non-critical work, fails closed rather than blocking paint, and treats every host page as untrusted input.

What it covers

• Runtime — injection, lifecycle, configuration and teardown of widgets on a live page, with style isolation so the host cannot leak in and the widget cannot leak out.
• Widget library — the reusable surfaces themselves, plus a React harness for developing them against realistic pages.
• Plugins — a configuration-driven extension layer for behaviour that varies per customer.
• Instrumentation — capturing interaction data cleanly enough to attribute behaviour to specific elements, which is what makes the analytics useful rather than decorative.