Last updated: October 2026.
Short answer: to build a Facebook Messenger bot, connect your Facebook Page in Mavibot (Channels, then Facebook), put the word start in the condition of the start block, build a welcome flow with buttons and test it in Messenger. You need a Facebook Page, not a profile or group, and admin rights. The free plan is enough.
What you need before you start
A Facebook bot connects only to a Facebook Page. A personal profile or a group won't work. You also need to be the owner or an administrator of the Page, and messages must be enabled for it. The examples below use a short test flow built with Mavibot's Facebook Messenger bot builder.
If you don't have a Mavibot account yet, sign up. On the project creation screen there is a field for a promo code at the bottom. Enter MAVI10 there to get 10 days of the top plan free.
Step 1. Connect your Facebook Page
Open Channels in Mavibot. The Connect a new bot list shows all the channels. Click Facebook.
A window opens where you log in to Facebook and authorize access. Turn on all the permission toggles. Mavibot may also offer to connect your Instagram Business account, which is optional. Then the Create a bot for Facebook Messenger window asks which Page the bot will be linked to. Choose your Page in the list and click Done.
If the Page you need is not in the list, Mavibot doesn't have permission for it yet. Log out in Mavibot, click Log in with Facebook, choose Edit settings and select the Page. The full instructions are in the documentation, How to connect a Facebook page (updated July 2026).
Step 2. Set the start trigger
After the connection, Messenger shows a Start button to new users, and Mavibot creates the matching trigger. Add the word start to the condition of your start block, because this is what launches the bot. In the screenshot the trigger is the word start with the match type Exact match. The welcome text that a person sees before pressing Start is set in the settings of your Facebook Page, not in Mavibot.
Step 3. Build the first flow
A flow is a chain of blocks connected by arrows. The builder works the same way in every channel, so if you have built a bot before, you already know it. If not, how to make a Telegram bot explains the basics step by step.
The screenshots show a short test flow. The start block has the trigger start and a greeting. After 60 seconds a Chat block asks a question with two buttons, "Yes, let's do it" and "Not right now". Each button leads by an arrow to its own answer block. You set the delay on every arrow, and the screenshot shows 60 seconds and 24 hours.
The same blocks can also answer comments on your Page and move the person into a private conversation. For the Instagram version of this idea, see auto replies to comments and stories.
Step 4. Add a carousel
A carousel shows products as swipeable cards. It can have from 2 to 10 cards, and each card has a title, a description, an image and buttons. You create the cards in the Calculator field of a block. First put the cards in a variable. Here is an example with two made-up cards:
p = [
{"title": "Chocolate cake", "description": "Rich chocolate cake, serves 8", "image": "https://example.com/cake.jpg", "buttons": [{"text": "Order"}]},
{"title": "Berry tart", "description": "Fresh berries on vanilla cream", "image": "https://example.com/tart.jpg", "buttons": [{"text": "Order"}]}
]
On the next line of the same field, add:
r = send_carousel(p, '')
Leave #{None} in the Response field. Fill in either the title and description or the image for every card. A button can also open a link if you add a url parameter to it.
Step 5. Test the bot
Open your Page in Messenger from another account and press Start. Press every button, for example "Yes, let's do it", and check that each answer arrives. Send a message the bot doesn't expect, to see what it replies. Fix the flow and test again before you announce the bot.
If you want people to arrive from advertising, Meta's ads that click to Messenger open a conversation with your Page when someone taps the ad, so your bot can greet that person. Meta describes the format in its documentation, Ads that Click to Messenger.
Facebook Messenger 24-hour messaging rule
Facebook limits when a Page may message a person. According to Mavibot's documentation (updated July 2026), you have 24 hours after the person subscribes or writes to send any messages, including promotional ones. Every reply from the person opens a new 24-hour window. If the person does not answer within 24 hours, Facebook allows one more message, which can include a button and an offer.
After the window, only limited message types are allowed, such as reminders about events the person signed up for. The documentation says that promotional messages after the window are prohibited and that breaking the rule can get your Page blocked. These rules apply to any message you send: from a bot, a broadcast or by hand. Meta can change them, so check its Messenger Platform policy before you send anything outside the window.
To send one message to many subscribers, see how to send a Telegram broadcast. The Mailings section works the same way for Facebook, and the 24-hour rule applies to it.
Add a persistent menu
A persistent menu is a permanent set of buttons next to the message field, for example business hours, the shop or a link to your site. It supports link buttons and buttons that send a text to the bot. You can show different menus for different languages and even hide the message field so that people use only the menu. The function and its parameters are described in the documentation: Facebook persistent menu.
How much it costs
You can connect a Facebook Page on the free plan. The plans:
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Free plan, $0: 50 bot messages a day.
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Business, $39 a month: up to 10,000 bot messages a day and up to 1,000 emails a day.
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Mavibot AI, $59 a month: everything in Business, plus Mavi, an AI employee for sales.
The AI assistant works on paid plans and during the trial. New accounts get a trial of the top plan: 3 days, or 10 days with the promo code MAVI10. The prices come from the pricing page and may change.
Build your Facebook Messenger bot
Start free, enter the promo code MAVI10 on the project creation screen for 10 days of the top plan, and connect your Page with the Facebook Messenger bot builder.
Frequently asked questions
What is a Facebook Messenger bot?
A Facebook Messenger bot is a program that answers messages sent to your Facebook Page. It can greet people, answer common questions and show products in a carousel, and it works at any hour.
Do I need a Facebook Business Page to build a Messenger bot?
You need a Facebook Page, not a personal profile or a group. You also need to be the owner or an administrator of the Page, and messages must be enabled for it.
Can I connect a Facebook Page on the free plan?
Yes. You can connect a Facebook Page and build a bot on the free plan, which includes 50 bot messages a day.
What if my Page is not in the list when I connect it?
Mavibot probably doesn't have permission for that Page yet. Log out in Mavibot, click Log in with Facebook, choose Edit settings and select the Page.
What is Facebook's 24-hour messaging rule?
You have 24 hours after a person subscribes or writes to your Page to send any messages, including promotional ones. Each reply from the person opens a new 24-hour window. After the window, only limited message types such as event reminders are allowed.
Can a Facebook Messenger bot send promotional messages after 24 hours?
No. According to Mavibot's documentation, promotional messages after the 24-hour window are prohibited, and breaking the rule can get your Page blocked. Check Meta's Messenger Platform policy for the current rules.
Can I show products in Messenger?
Yes. A carousel shows from 2 to 10 cards, and each card has a title, a description, an image and buttons. You create the cards in the Calculator field of a block.
Can the bot reply to comments on my Page?
Yes. You set it up with blocks in the builder, and the bot can move the person from a comment into a private conversation.
How can a Messenger bot help with lead generation?
The bot can ask a few questions, save the answers and add the contact to your CRM as a lead. It can also start a private conversation with people who comment on your Page.
Can I start the bot from a Facebook ad?
A Click-to-Messenger ad opens a Messenger conversation with your Page, so the bot can start from it like from any first message. Test it before you launch the ad.
Does the AI assistant work on the free plan?
No. The AI assistant works on paid plans and during the trial: 3 days, or 10 days with the promo code MAVI10.