WhatsApp in Pipedream: HTTP trigger, a Node.js step and environment variables

Step by step

1. 1

   Create the environment variables

   In Settings > Environment Variables (or Variables inside a project), create ZAPZAP_API_KEY, ZAPZAP_API_SECRET and ZAPZAP_INSTANCE_ID. The documentation says new variables are secret by default and the value cannot be changed afterwards. The keys come from Settings > API at app.zapzapapi.com.

2. 2

   Create the workflow with an HTTP trigger

   Pipedream generates an endpoint URL just for the workflow. The documentation warns that, by default, HTTP triggers are public and require no authorization, and that bodies above 512 KB return 413.

3. 3

   Register the URL on the instance

   Call PUT https://api.zapzapapi.com/api/v1/instances/{id}/webhook with webhook_url (the URL from the previous step) and events (for example, messages). The response carries the webhook_secret (whsec_). Test with POST /instances/{id}/webhook/test and watch the run in Pipedream.

4. 4

   Answer the webhook first

   If $.respond is never called, the documentation says the endpoint returns a 400 error. Use $.respond with immediate: true to answer right away and let the other steps run afterwards. ZapZap retries when your endpoint fails.

5. 5

   Send the reply in a Node.js step

   Use the example code: process.env for the keys, fetch for POST /{instanceId}/send/text with number and text. Replace the fixed number with the event's sender, reading the data fields of the envelope you receive.

6. 6

   Protect the endpoint

   Since the trigger is public by default, validate the origin. ZapZap signs each delivery in the X-ZapZap-Signature header over the raw body; the documentation I read does not explain how to get the raw body in the trigger, so confirm that option in your account, or set up the authorization token Pipedream offers.

// Pipedream Node.js code step. Environment variables (Settings > Environment Variables): ZAPZAP_API_KEY, ZAPZAP_API_SECRET, ZAPZAP_INSTANCE_ID
export default defineComponent({
  async run({ steps, $ }) {
    await $.respond({ status: 200, body: "ok", immediate: true }); // answer the webhook first
    const base = "https://api.zapzapapi.com/api/v1/" + process.env.ZAPZAP_INSTANCE_ID;
    const r = await fetch(base + "/send/text", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        "x-api-key": process.env.ZAPZAP_API_KEY,
        "x-api-secret": process.env.ZAPZAP_API_SECRET,
      },
      body: JSON.stringify({ number: "5511999999999", text: "Received: " + steps.trigger.event.body.event }),
    });
    return { status: r.status };
  },
});