# One call out. One kind of content.

A WhatsApp send is one POST carrying a recipient and exactly one kind of content: a template, or free-form text, image, video, audio, sticker, document, or location. The response is a 202 with a message ID, and delivery reports itself on webhooks you already handle.

## The same send in every runtime.

Sending is the core verb of the Bird WhatsApp API. The SDKs cover Node.js, Python, Go, and PHP, and the CLI and raw HTTP take the same body. A first send can name a Bird-managed template, which picks its own sender, so nothing has to be provisioned before you watch a real message land.

## Exactly one content kind, never two.

A request carrying no content is refused with a 422, and so is one carrying two. A template is the only content WhatsApp delivers outside an open customer service window, which is why it is what starts a conversation. Free-form content is a reply, and it always names the number it comes from.

## What every send carries.

The parts of the request that are not the message: who it is for, who it is from, how a retry behaves, and what rides back to you on every event.

## A retry that does not double-send.

A timeout tells you nothing about whether the message went out. Send the retry with the same idempotency key and the API replays the original response instead of processing the request again, and marks the replay on the way back so your logs can tell the two apart.

## One recipient per call.

There is no batch endpoint on WhatsApp: fan out in your own loop and pace against the rate-limit headers on each response rather than a constant you picked. Sends are metered per message, and pricing moves with the destination country and the template's category.

## Go deeper in the docs.

Read sending WhatsApp for the full request contract, WhatsApp events for the lifecycle and its payloads, and webhooks for endpoints, signatures, and retries.

## Your first WhatsApp send, today.

Sending is one capability of the Bird WhatsApp API: templates, inbound, numbers, and analytics ship with it, on infrastructure we have run for a decade.