WhatsApp Coexistence: App and API on One Number

For years, moving a number to the WhatsApp Business API meant giving up the WhatsApp Business app on it. You lost the app, and often the chat history your team relied on. With coexistence, the same number works in the app on your phone and on the API at the same time, so the AI Agent can answer customers while the owner keeps replying from the phone.

How it works

You connect your existing WhatsApp Business app number through a provider such as Querygen, scan a code in the app, and choose to keep using it. From then on, one-to-one chats are mirrored both ways. A reply typed on your phone shows up in the API tool, and a reply sent by the API tool shows up on your phone.

• You need WhatsApp Business app version 2.24.17 or newer.
• Contacts sync, along with one-to-one chats from the last six months. Group chats don't sync.
• The history sync has to happen within 24 hours of connecting, and it runs once.
• Coexistence is available in nearly every country the Cloud API supports. EU and UK numbers were added in November 2025.

What keeps working, and what stops

What it costs

• Messages you send from the WhatsApp Business app stay free.
• Messages sent through the API are billed at normal API prices: templates by category, and free-form replies beyond 1,000 per number each month.
• Querygen's plan is a separate charge, listed on our pricing page.
• Messages from the app don't open or extend the API's 24-hour window, and don't change what the API charges.

Limits to know before you switch

• Speed is capped at 20 messages a second on a number used in both places. That's fine for most small businesses but slow for very large campaigns.
• Keep the phone active. If the app on the main phone isn't used for about 14 days, the number disconnects from the API. Linked devices disconnect after about 30 days of not being used.
• No Calling API. Calls keep ringing in the app. To answer WhatsApp calls in a browser and route them to your team, the number has to be fully on the API. See our calling guide.

What we learned building it

These are the parts that broke first when we added coexistence to Querygen.

1. Your replies from the phone arrive as echoes. Meta sends each message typed in the app as a separate webhook. Store it as an outgoing message in the conversation, or your inbox will show only half of each chat.
2. When a person replies, the bot should step back. If the owner answers from the phone, an AI agent replying to the same customer a minute later looks broken. We pause the AI Agent on that chat when a reply comes from the phone.
3. Import old chats without alerts. Six months of old chats arriving at once shouldn't raise unread counts, alerts or follow-ups. We import history quietly, without running any automations on it.

Who should use coexistence

• Use it if the owner or a small team lives in the WhatsApp Business app, and you want the AI Agent or campaigns on the same number without losing it or its history.
• Move fully to the API if you send large campaigns, want WhatsApp calls answered in a browser, or nobody needs the app anymore. Our WhatsApp Business API setup guide walks through a full move.

Meta's coexistence documentation has the full list of supported features.

Frequently asked questions