During technical investigation for the [1] booking system project, the Zapier-based integration between Bookly and Square was found to be unworkable. The data Zapier pulls from Square does not match what Square requires to create an appointment, making the integration path a dead end in its current form.
This failure was a primary driver of the architectural review that followed, and ultimately prompted a go/no-go decision on Bookly itself.
Zapier's Square connector pulls data from Square, but the fields it surfaces do not align with what Square's Appointments API requires to write a booking back:
"The data that Zapier pulls from Square doesn't necessarily seem to match what we need to create an appointment in Square, which is weird. So the data it pulls from Square doesn't match what is required in Square."
— Chris Ostergaard, integration specialist
The investigation also surfaced that resolving this would likely require direct API/webhook work beyond standard Zapier configuration — a scope and skill-set mismatch for the integration role on this project.
The failure of this integration path exposed a broader problem: the proposed architecture involved five systems — Square, Bookly, Zapier, WooCommerce, and Google Calendar — with circular dependencies and no clear single source of truth.
The core principle established during review: Square must remain the single source of truth for inventory, payments, staff schedules, and availability. Any integration architecture that requires Zapier to mediate between Bookly and Square introduces unacceptable risk to in-store appointment operations.
See [2] for the broader architectural analysis.
The WooCommerce route — Bookly → WooCommerce → Square — was identified as a potential alternative. WooCommerce already has a working native connection to Square for products (no Zapier involved). The open question is whether Bookly can reliably hand off scheduling data to WooCommerce for checkout, without requiring Zapier as an intermediary.
This path was assigned for further investigation. See [3] for action items and owners.
Zapier's read and write field sets for a given platform are not always symmetric. A connector that can successfully trigger on Square events may not expose the correct fields to create records in Square. Before committing to a Zapier-mediated integration between two platforms, validate both directions of data flow against the target platform's write API requirements — not just the fields Zapier surfaces in its UI.