Pricing and allowances

Try the Messaging API in the sandbox or on the free plan before connecting real customers. Plans cap how many people your apps talk with on each channel, not how many messages you send.

Plans

Plan	Price	Senders	People per channel
Free	$0	Flow’s shared senders, through the free trial	25 in total
Shared	$30 a month	Flow’s shared senders, including the shared iMessage line, and your own bot or number	300 a month and 200 a day
Dedicated	$120 a month	An iMessage line of your own, plus Flow’s shared senders	1,000 a day on its own senders, no monthly cap; 300 a month and 200 a day on Flow’s shared senders

• Free starts on its own: your first sign-in at flow.engineer (the dashboard), or the first key you make there, starts your account’s free trial, once. The Flow CLI (npx @flow-engineer/flow setup) starts the same trial. The trial opens Flow’s shared senders, the shared iMessage line included, to every app of the account, in test and live mode. People join an app by sending its join message.
• Shared and Dedicated are set by the Flow team after you agree terms with them; there is no checkout. Write to samyak@flow.engineer or prabal@flow.engineer with your account or app ID (GET /v0/app). A paid plan replaces the trial’s and the sandbox allowance’s limits for every app of the account, and an account that had the free trial keeps the shared iMessage line.
• Dedicated add-ons: SMS and RCS from the same number is included on the shared line and an add-on on a dedicated line. Call forwarding comes with the SMS/RCS add-on, on dedicated lines only. See iMessage.

Who counts

• A person counts once in each window, with their first inbound message on that channel, one-to-one or in a group chat, over all the account’s apps and both modes. Group members who never write do not count, and neither do calls, your own sends or simulated contacts.
• Days are UTC days and months UTC calendar months. People on Flow’s shared senders and on your own senders are counted apart.
• GET /v0/app shows the caps that apply now and what is used, in the account’s people; the dashboard’s Usage card shows the same. The numbers are settings and may change, so read them there.

Past a limit

A new person past a limit is held: their messages are kept but not delivered to your app, the dashboard shows them as held. Sends to a held person answer 403 permission, channel_code sandbox_contact_limit on the free trial and plan_people_limit on a paid plan. They are let in, with their kept messages in order, once a place frees: when the day or month rolls over (the free plan’s total never does), when you delete a contact (DELETE /v0/contacts/{contact_id}), or when the plan or its limits change. On the free trial a held person’s messages are kept for 30 days. People who already have a place keep it. In a group chat, a held writer’s messages are kept the same way and never hold up the others’: the rest of the group’s messages still arrive, and the held writer’s arrive in the group once they are let in.

Sandbox allowance

Apps without the free trial or a paid plan, such as an app made with POST /v0/sandbox/keys and claimed later, use the sandbox allowance, on the Telegram sandbox bot:

	Without an account	Signed in
Contacts	1	3
Outbound messages	50 total	100 per contact
Key expiry	7 days	No expiry
Shared allowance	Per anonymous app	Across the person’s apps

Only outbound messages count. Keys and sign-in explains claiming an app and reading its remaining allowance.

Before going live

Use a live key, and a dedicated sender when customers should see your own bot, number or line. Confirm the plan, included usage, sender charges and retention for your account before sending customer traffic.

With your own WhatsApp Business Account, Meta bills its messaging fees directly to your business. If you use a Flow-provided sender, confirm how channel fees apply to that sender.

Self-hosting an agent does not self-host the Messaging API. The framework is open source; Flow Messaging remains a hosted service.

Go live

Connect the sender and verify delivery with a live key.