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WhatsApp platform

How Meta's WhatsApp Business Platform actually behaves: what its APIs accept, what they accept and then silently ignore, what changes on a date Meta has announced, and who sits between a business and Meta.

Covered here: 24-hour customer service window · Business Solution Provider · catalog_management scope · catalogue sync · eventual consistency · HMAC SHA256 · item_group_id · Meta Commerce Catalog batch API · Meta Tech Provider · October 1 2026 WhatsApp charges

• 29 August 2026 · platform & cost

  The day there is no free way to answer a WhatsApp customer

  Meta starts charging for WhatsApp service messages on 1 October. It starts charging for utility templates inside an open window on the same day, which closes the escape route every explainer is recommending. Our own cost screen called those replies free in six places, including a recommendation that overstated what you had wasted. Also: a deadline we asserted nine times and could not verify, and why Meta's own pricing page still says the window is free.

• 28 August 2026 · commerce

  Building a WhatsApp catalogue that tells the truth

  Meta's catalogue batch endpoint returns HTTP 200 even when every item was rejected. The script we wrote specifically to verify a token could write reported success against a catalogue that was empty and had always been empty. Eleven bugs from three weeks of building catalogue and product infrastructure, almost all of the same shape: something reporting success for work it had not done. Includes a paywall that only worked while the feature was switched off, a complete edit endpoint with no button behind 5,187 passing tests, and the two calls we got wrong ourselves.

• 8 August 2026 · the landscape

  What you are actually buying when you buy WhatsApp

  Not about us, for once. Ask an owner sending ten thousand messages a month what Meta charges them per message and most cannot say, because the number arrives inside somebody else's invoice. A map of the three layers: what Meta actually bills for (less than you think, and replying is free), why the Solution Partner and Tech Provider distinction is about billing rather than capability, what the middle layer genuinely earns its fee doing, and the three questions that decide whether you can ever leave.

• 31 July 2026 · engineering

  WhatsApp payments with Razorpay: what the docs leave out

  Collecting payment inside a chat in India, written while shipping it. The order_details payload that passes validation, why a bare UPI VPA is rejected, the INR-only rule and how it fails silently, payment links versus subscriptions in a thread, whether your notes reach the webhook, and the signature check that rejects every real event while returning a clean boolean.

• In progress

  The half of a sale that nobody demos

  Every platform shows you the payment landing. Almost none show you the twenty minutes afterwards: who gets told, who packs it, what the buyer hears while they wait, and what happens when it ships four days later and the messaging window has closed.

• In progress

  Where the ask ends and the shop begins

  A payment request is messaging machinery. A product library is a commerce application, and the part most likely to be replaced by a real one. On finding that seam in our own code, and making it a documented extension point instead of a function that happened to sit in the middle of a file.

• In progress

  What a feature looks like when nothing consumes it

  Contact limits computed on every request and enforced nowhere. A tier ladder that is marketing copy at runtime. On the difference between building a capability and shipping one, found in our own codebase.