How does Monely run its WhatsApp on the official API?

In short: through ZapClaw. Since July 2026, Monely's WhatsApp numbers have run on the official WhatsApp API: messages arrive on Monely's webhook, and replies go out through the REST API with an idempotency key, the header that stops a retry becoming a second message. The company behind Monely also runs ZapClaw, so this is our own product on our own gateway.

What a WhatsApp assistant cannot get wrong

Monely is a personal finance app. People record expenses by sending it a text, a voice note or a photo of the receipt on WhatsApp, and ask it for balances and summaries in the same chat. That only works if every message reaches Monely, every reply goes out once, and every photo and voice note can be downloaded.

What Monely built on ZapClaw

• An idempotency key on every reply. Monely sends each reply through the REST API with its own Idempotency-Key. Once a send has a result, repeating it with the same key within 10 minutes returns that result and sends nothing.
• Delivery codes it acts on. DELIVERY_INDETERMINATE means Meta answered with an error that does not rule out delivery; IDEMPOTENCY_IN_PROGRESS means the first call with that key is still running. In both cases Monely waits instead of sending again right away.
• Every message on its webhook. Each one arrives as a signed POST, with up to 3 delivery attempts. When Meta hides the sender's number, the event still carries data.from_user_id, and Monely replies to that id.
• Receipt photos and voice notes. Each media message arrives with a ready media_url, and the download answers with a status that says what to do: retry a 404, wait out the Retry-After of a 429 or a 503, stop at a 410.

What this means for your integration

• The official API. Every message goes through Meta's official WhatsApp Cloud API, with no unofficial library in the path.
• A webhook in, a REST call out. Moving an existing bot to ZapClaw means changing the endpoint and the auth header, not rewriting it.
• Sends you can retry. The idempotency key, the delivery codes and the media statuses are all in the public API documentation.

More on this

• Retrying a send without sending it twice
• Webhook events and the signature check
• Pricing: unlimited numbers on the Negócio plan, R$ 99 per month