Send Your First WhatsApp Message with One Link (No Coding)

In Part 1 you created your API key. Now let us send a real WhatsApp message with it. You will use our free API Tester. It builds the link for you, shows how the message will look on the customer's phone, sends it and tells you in plain words what happened.

First, understand the link

Our API is just a web link. Every time this link is opened, one WhatsApp message goes out. The link has a few parts. Each part is written as name=value, and the parts are joined with &.

One important rule: the 24-hour window

WhatsApp allows a normal text message only if the customer has sent you a message in the last 24 hours. For a customer who has not written to you, use an approved template (Part 3).

The tester reminds you of this rule under the number box: Works only if this customer messaged you in the last 24 hours. Otherwise send a Template. Click How to test? at the end of that line for the same tip.

Every page has 3 steps

Each page of the API Tester works the same way, so you learn it once:

• Step 1 — Your API key: paste your key once. After that it shows as one short line, with the key hidden.
• Step 2 — Your message: the customer's number and your message.
• Step 3 — Check and send: the dark panel on the right. From top to bottom: How it looks on the phone (your message, the way the customer will see it), the gold Send now button, a short line under it, the Answer (only after you send), a closed fold Link & code for your software and the white button Ask AI to connect this.

After the first page you open, every page has ← Back to … at the top, like ← Back to Overview. It takes you back to the page you came from.

Step by step: send a test message

1. Open your phone and send "Hi" to your business WhatsApp number. (This opens the 24-hour window.)
2. In the panel, go to WhatsApp API → Step 3 — Try it → click Open API Tester. The tester opens in a new tab with your key already filled in. You can also open epublictouch.com/app/api directly and paste your key in step 1, Your API key.
3. In the left menu, under Send a message, click Text. (On a phone, tap ☰ Menu first.)
4. Look at step 1. It shows one line: API key ept_••••1a2B · Sends from your main WhatsApp number. Your key is hidden with dots. Nothing to do here.
5. In step 2, Your message, type your own mobile number in Send to (WhatsApp number). A 10-digit Indian number is fine. We add 91 for you. A green line shows Will be sent to +91 …
6. Type your Message, for example Hello! This is my first API message.

7. Now look at the dark panel on the right, Check and send (on a phone, it comes below your message). Under How it looks on the phone you see your message exactly as the customer will get it. Check the phone before you press Send now: is the text right, with no spelling mistake? The line under the button says Ready. Press Send now to send it to the customer.
8. Click the big gold Send now button. (On a phone, a Send now bar stays at the bottom of the screen until you reach the button.)

Read the answer

The answer comes right under Send now. First a short line, like Done at 11:42 AM. The answer and the ticks are below. Then the Answer box, in simple words:

• Green means it worked. The green line changes with the ticks: WhatsApp got your message. → Sent ✓ — on its way to the customer. → Delivered ✓✓ — on the customer's phone. → Read ✓✓ — they opened it.
• Red means it was not sent. The line under Send now says Not sent. See below why and what to do. The red box tells you why and What to do, for example This customer has not messaged you in the last 24 hours.

After a green answer, the Delivery row fills in by itself: Accepted (WhatsApp got it) → Sent (on its way) → Delivered (on their phone) → Read (they opened it). It keeps checking for one minute. If you got a red answer about the 24 hours, just click Send a Template instead. At the bottom of the answer, Technical details (for your developer) has the full answer with its codes. You can leave it closed.

Use the link anywhere

Under the answer, click Link & code for your software. This fold is closed until you click it. Inside you see Your link and a Copy link button. Click Copy link. On screen your key is hidden, but the copied link has your real key in it, so the link works.

Now you can use the link in any software that has an "SMS API" or "URL API" setting. Many billing, school and CRM software have one. Usually you replace the customer's number and message with the software's own tags, like {mobile} and {message}. Check your software's help page for the exact tag names.

Not sure where to paste it? Click Ask AI to connect this, the white button just under the fold. ChatGPT, Claude or Gemini will guide you step by step (Part 12).

Extra settings (optional)

Under your message there is a fold called Extra settings (optional). You can leave it closed. Open it only when you need one of these:

• Customer's name: if the number is new, we save it in your Contacts with this name.
• Your reference no.: your own number for this message, like an order or bill number. The same reference is never sent twice within 24 hours, so it is safe if your software tries again.
• Skip the 24-hour check: send even if we have no message from this customer in the last 24 hours. Use it only if you are sure they wrote to you recently. WhatsApp may still refuse it.

(For programmers: turn on Developer view to see the names these boxes use in the link: name, ref and force.)

Common questions

I got the green answer but no message came. Why?

Check three things: the number has WhatsApp, you sent "Hi" from that number in the last 24 hours, and the number is written with the country code. If WhatsApp could not deliver it, the green line changes to Not delivered and the reason shows below it. The Errors page of the tester (under Help) starts with a short Message not received? checklist (Part 9).

Can I paste the link in a WhatsApp chat to test?

No. WhatsApp, Facebook and Telegram open links in the background to make a preview. We block these previews on purpose, so they never send a message by mistake. Use the tester or a normal browser.

Is the tester safe? It has my key.

Yes. The key stays in your browser and goes only to our server. On screen it is hidden with dots, even inside Your link. To see it, click Change in step 1 and then the eye button next to the key. Remember on this device (also under Change) is off by default. Turn it on only on your own phone or computer.

What is the "Developer view" switch at the top right?

It is for programmers. It shows ready code (cURL, Python, Node.js, PHP, Google Sheets), example answers and the technical name of every box. Keep it Off if you do not need code. Part 8 shows how to use it.

What next?

Text messages work only inside the 24-hour window. To message any customer at any time, use templates. That is Part 3.

Next: Part 3 — Template messages