processUpdate

This page describes the processUpdate() function in zalo-bot-js, used to feed an update into the SDK event pipeline.

It is the core function for webhook-based flows: your HTTP server receives the payload, then passes it to processUpdate() so the SDK can parse it and emit the matching listeners.

Function signature

processUpdate(update: Update | JsonObject): Promise<void>

What this function does

When called, the SDK will:

1. parse the payload into Update if needed
2. ignore updates without message
3. update nextUpdateOffset when updateId exists
4. emit listeners for each derived eventType
5. run all listeners registered with onText()

Example

await bot.processUpdate(payload);

Webhook example

app.post("/webhook", async (req, res) => {
  await bot.processUpdate(req.body);
  res.sendStatus(200);
});

Practical notes

• updates without message are ignored
• if you use startPolling(), the SDK calls processUpdate() internally

Next

• See setWebhook to configure webhook delivery.
• See on and onText to handle parsed updates.

Last updated: April 5, 2026