What is the difference between keyword replies and AI replies?

Keyword replies are hardcoded text responses fired when an incoming message contains a specific word. For example "PRICE" sends your price list. They are unlimited and free. AI replies use Voice DNA to generate context-aware responses that read the full conversation history. AI uses credits because it calls a paid LLM under the hood.

Can I use my existing WhatsApp Business number?

Yes, if your number is currently on the WhatsApp Business app (not the consumer app), you can migrate it to Cloud API without losing chat history. We export your conversation history before migration. If your number is on the consumer app, you will need to use a different number or delete the consumer app account first.

What if my keyword auto-reply does not fire?

The most common reasons: (1) the rule is in draft mode, not live, (2) the keyword is set to exact match but the customer message contains punctuation, (3) the webhook is not subscribed in Meta Developer Console. PostEngage runs a diagnostic in the dashboard that catches all three within seconds.

How to Automate WhatsApp Replies in 2026: Free Keyword Auto-Replies + AI Responses (Step-by-Step)

What You'll Need

Automating WhatsApp replies properly means using the official WhatsApp Cloud API from Meta — never browser emulators or unofficial mods, which get numbers banned within weeks. Here is the checklist:

A Meta Business Manager account (free to create at business.facebook.com).
A phone number not currently active on the WhatsApp consumer app. New SIMs work; landlines work if they can receive SMS or voice OTP.
A verified business in Meta Business Manager (basic verification is free; full verification is free but takes 2-3 business days for documents).
A PostEngage.ai account — free, no card required, 100 AI credits on signup.

Total cost so far: zero. Meta does not charge for Cloud API access and gives you 1,000 service conversations per month free. PostEngage gives you keyword automations free forever.

Step-by-Step: Automate WhatsApp Replies in 10 Minutes

Step 1: Create a free PostEngage.ai account

Head to postengage.ai/signup and sign up with your business email. Verify the email link. You now have a dashboard with two channels: WhatsApp and Instagram. We will focus on WhatsApp.

Step 2: Click "Connect WhatsApp"

In the dashboard sidebar, click Channels → WhatsApp → Connect. The Meta-approved embedded signup popup opens. This is the official Meta flow — you stay inside Meta's domain to authorize PostEngage as your Business Solution Provider.

Step 3: Log into Facebook Business Manager

Log in with the Facebook account that owns your Business Manager. If you do not yet have a Business Manager, the embedded flow walks you through creating one (takes 90 seconds).

Step 4: Select or create your WhatsApp Business Account

Pick an existing WhatsApp Business Account (WABA) or click "Create New". Enter your legal business name. The WABA is a container that holds your phone numbers and message templates.

Step 5: Add and verify your phone number

Enter the phone number you want to use. Meta sends an OTP via SMS or voice call. Enter the 6-digit code. The number is now live on Cloud API. This number cannot be used on the consumer WhatsApp app simultaneously.

Step 6: Set your display name and business profile

Enter your display name (must match a name you do business under), business category, description, website, and address. Upload a profile photo. Meta auto-approves display names that match your verified business documents.

Step 7: Create your first keyword automation

Back in PostEngage, go to Automations → Keyword Replies → New Rule. Configure:

Trigger word: PRICE
Match type: Contains (case-insensitive)
Reply: your price list, PDF, or image
Schedule: 24/7 or business hours only

Toggle the rule to Live. That keyword is now answering automatically.

Step 8: Add 4-6 more keyword rules

Repeat for your other top inbound questions. Common rules for Indian businesses:

HOURS → opening times
LOCATION → Google Maps link
BOOK → Calendly link
MENU or CATALOG → PDF or WhatsApp catalog
ORDER → order status flow
HELP → human agent escalation

Step 9: Enable AI Voice DNA fallback (optional)

In Automations → AI Fallback, toggle on AI replies for messages that do not match any keyword. The AI uses Voice DNA — it learns your brand tone from sample conversations. Each AI reply uses 1 credit (you have 100 free).

Step 10: Set business hours and offline replies

Under Settings → Business Hours, define when your team is available. Outside hours, you can send an "auto-acknowledge" that triggers human follow-up the next morning — still free, still keyword based.

Common Issues and Fixes

"My number is already on the WhatsApp consumer app"

Delete the consumer app account first (Settings → Account → Delete My Account). Wait 30 minutes. Then add the number to Cloud API. Your chat history will be lost on the consumer side — export it first if needed.

"OTP not received"

Switch from SMS to voice OTP in the Meta flow. Indian operators sometimes block SMS from international short codes. Voice OTP works 100% of the time.

"Keyword rule not firing"

Three checks: (1) is the rule toggled live, (2) is the match type set to Contains rather than Exact, (3) is the webhook subscribed (PostEngage shows a green status). The diagnostic tab catches all three.

"Display name rejected"

Meta requires the display name to match a name you legally do business under. If you trade as "Anjali's Kitchen", complete business verification first or submit your GST certificate as proof.

Verify Your Automation Works

Three tests every store should run before going live with customers:

Test 1

From your personal WhatsApp, message your new business number with each keyword. Confirm the right reply arrives in under 5 seconds.

Test 2

Send a non-keyword message like "Hi". The AI fallback (if enabled) should reply within 10 seconds. Check that the tone matches your brand.

Test 3

Check the PostEngage dashboard analytics. Every message should appear in the conversation log with timestamps, rule fired, and credit usage.

The PostEngage Shortcut: 3 Minutes Instead of 10

If you already have a verified Meta Business Manager and a free number, the full setup actually takes about 3 minutes. Here is the timeline:

0-60s

60-120s

Click Connect WhatsApp, complete Meta embedded signup, verify OTP.

120-180s

Create 3 keyword rules (PRICE, HOURS, BOOK). Toggle live.

Need help picking the right keywords? Read our keyword triggers guide — the strategy translates 1:1 from Instagram DMs to WhatsApp.

FAQ

Is automating WhatsApp replies allowed by Meta?

Yes — automation on the official WhatsApp Cloud API is fully sanctioned. PostEngage is a Meta Business Partner safe integration. The only WhatsApp automation NOT allowed is unofficial mods or browser scrapers.

Is keyword auto-reply really free forever?

Yes. Unlimited keyword rules, unlimited triggers, no credit card. You only pay Meta the standard per- conversation rate (and Meta gives 1,000 free service conversations per month).

What is the difference between keyword and AI replies?

Keyword: hardcoded text fired when an incoming message contains a specific word. AI: Voice DNA generates a context-aware reply. Keyword is free; AI uses credits.

How fast does the auto-reply send?

Keyword replies fire in under 3 seconds. AI replies take 4-8 seconds because they call a language model. Both are faster than human response times.

Ready to Automate? Start Free

Free keyword auto-replies forever on the official WhatsApp Cloud API. 100 AI credits on signup. No credit card.

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How to Automate WhatsApp Replies in 2026: Free Keyword Auto-Replies + AI Responses