Every booking that comes through an OTA costs a hotel 15-25% in commission, and the alternative — a website "book now" button that dumps enquiries into an inbox — means someone re-keys each reservation into ERPNext by hand, risks overselling a room, and loses the guest to a faster competitor. ERPNext has strong back-office hospitality building blocks (Hotel Room, Hotel Room Reservation, Hotel Room Pricing, Hotel Room Package DocTypes), but out of the box there is no public, embeddable booking front end: no real-time availability check exposed to your website, no guest-facing checkout, and no online payment capture that lands a confirmed reservation straight into the PMS. That gap is exactly where hotels keep paying commission.

We build a proper Frappe app — its own module, DocTypes, and hooks.py — that closes the gap. An embeddable, mobile-first booking widget (a lightweight JS bundle you drop into any website, including your existing WordPress or static site) calls a set of guest-safe @frappe.whitelist(allow_guest=True) methods over the Frappe REST API. Those methods run an availability query against your ERPNext room inventory and pricing rules, return only bookable dates and live rates, apply promo codes and package deals server-side (never trusting client prices), and hold the room while the guest checks out. Payment is captured through your gateway of choice (Stripe, Razorpay, or a regional PSP), and on a verified payment webhook a server script creates the Hotel Room Reservation (or your customer reservation DocType) with the guest Contact, deposit or full-payment record, and correct status — all inside a single transaction so you never confirm a room you couldn't charge for.

The engine is wired into ERPNext's own mechanics rather than bolted alongside them. Availability and rate logic live in server scripts and whitelisted methods so the same source of truth drives both the widget and your reception desk. hooks.py doc events keep the widget honest — when a reservation is created, cancelled, or a room is blocked for maintenance, availability recalculates immediately. A scheduler event releases expired payment holds so inventory is never silently locked, and can push booking confirmations and pre-arrival emails. Guest-facing endpoints run under a tightly scoped guest role with rate limiting and input validation; staff-facing screens respect ERPNext role profiles and permissions so front-desk, revenue, and admin users each see only what they should. Client scripts add the desk-side conveniences (quick availability lookup, promo overrides), and everything targets Frappe/ERPNext v15 and v16.

Because this is build-to-order, we start from your actual property: room types, rate plans, seasonal and package pricing, deposit policy, cancellation rules, languages, and payment gateway. After a short scoping call we confirm the exact scope in writing, build against your requirements, and hand over installable source and a git repository — not a locked black box. Typical delivery is one working week from confirmed scope. We deploy to a staging bench for UAT, agree a rollback plan, then go live on your production bench and support you through the first weeks of real bookings. There is no instant download: what you get is a bench app engineered for your hotel and your ERPNext instance.