Business Setup

Connect a Meta WhatsApp Business Account to CallMissed, register the number, link an agent, and let AI write the first system prompt and templates.

Connecting a number binds your WhatsApp Business Account (WABA) to CallMissed, subscribes CallMissed to the WABA's webhooks, and registers the number on the WhatsApp Cloud API. After that, inbound messages flow to your agent and you can send from the API.

There are two ways to connect, and one thing you never have to do: you do not configure a webhook in Meta. Connecting subscribes the CallMissed app to your WABA automatically. See You never configure a webhook in Meta.

Prerequisites

A Meta Business account with a verified business.
A WhatsApp Business Account and a phone number in WhatsApp Manager. The number must not be tied to a personal WhatsApp app.
A payment method on the WABA in WhatsApp Manager. Until Meta has one, sends fail.
A CallMissed workspace.

Option 1: connect from the dashboard

Go to Settings → Integrations → WhatsApp in the dashboard and follow Embedded Signup. Meta's popup handles the account selection and consent, and CallMissed does the rest: exchanging the authorisation code, subscribing to webhooks, and registering the number with a two-step verification PIN.

This is the recommended path. It is also the only path that registers a brand-new number for you.

Option 2: connect an existing WABA from the dashboard

Use this when the number was set up outside Embedded Signup, for example registered directly in the Meta dashboard or migrated from another provider. Connecting it needs a long-lived business token, so it is done by a workspace owner or admin in the dashboard under Settings → Integrations → WhatsApp, not over the API. Once connected, the number is sendable from the API like any other.

If you are building your own Embedded Signup flow rather than using the dashboard, post Meta's callback data to:

POST /api/v1/whatsapp/onboarding/exchange · scope whatsapp:write

Field	Type	Required	Notes
`code`	string, 1 to 2048 chars	Yes	The exchangeable code from Meta's login callback. It expires in about 30 seconds, so post it immediately
`waba_id`	string, 1 to 64 chars	Yes	From the signup event data
`phone_number_id`	string, 1 to 64 chars	Yes	From the signup event data
`business_id`	string, max 64	No	From the signup event data
`bot_id`	UUID	No	Link an agent in the same call
`data_localization_region`	string, exactly 2 chars	No	ISO 3166-1 alpha-2 for data-at-rest residency, from Meta's supported list

curl -X POST https://api.callmissed.com/api/v1/whatsapp/onboarding/exchange \
  -H "Authorization: Bearer cm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "code": "AQBx-hBsH...code-from-meta",
    "waba_id": "102290129340398",
    "phone_number_id": "1234567890",
    "business_id": "441329482726",
    "data_localization_region": "IN"
  }'

CallMissed exchanges the code for a business token, saves the account and number, subscribes to the WABA's webhooks, and registers the number with a two-step verification PIN it generates and stores.

Response (200 OK)

{
  "account": {
    "id": "1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d",
    "waba_id": "102290129340398",
    "business_id": "441329482726",
    "name": "Acme Coffee",
    "currency": "INR",
    "review_status": "APPROVED",
    "account_status": "ACTIVE",
    "account_restriction_reason": null,
    "payment_setup_complete": true,
    "is_active": true,
    "created_at": "2026-04-19T12:00:00Z"
  },
  "phone_number": {
    "id": "9c2b7e30-1d8a-4c5f-9b3d-2f4a6e8b1c2d",
    "account_id": "1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d",
    "bot_id": "0a1b2c3d-4e5f-6a7b-8c9d-0e1f2a3b4c5d",
    "phone_number_id": "1234567890",
    "display_phone_number": "+91 80802 47309",
    "verified_name": "Acme Coffee",
    "code_verification_status": "VERIFIED",
    "quality_rating": "GREEN",
    "messaging_limit_tier": "TIER_1K",
    "throughput_level": "STANDARD",
    "registration_status": "REGISTERED",
    "registration_error": null,
    "name_status": "APPROVED",
    "ai_autoreply_enabled": true,
    "is_active": true,
    "created_at": "2026-04-19T12:00:00Z"
  },
  "fully_provisioned": true,
  "onboarding_error": null
}

Field	Type	Notes
`account`	object	The connected WABA
`phone_number`	object	The connected number. Its `id` is the `phone_id` you use everywhere else
`fully_provisioned`	boolean	`false` means the rows exist but a setup step did not complete. The connection is recoverable, so retry rather than starting over
`onboarding_error`	string, nullable	A short reason when `fully_provisioned` is `false`

Failures

Code	Meaning
`400`	Meta rejected the code (expired, already used, or for another app)
`403`	The code does not grant access to that WABA, the number is not part of it, or onboarding is blocked for this account
`404`	The `bot_id` does not belong to your workspace
`409`	The WABA or number is already connected to a different workspace
`422`	The body failed validation

The rows are saved before registration is attempted, so a failure at the last step leaves a recoverable connection rather than losing the WABA association. Check fully_provisioned and retry if it is false.

Reconnecting a number keeps its original PIN. WhatsApp has no way to disable two-step verification, so a reconnect reuses the stored PIN. If it cannot be read, you get 409 asking you to reset the PIN in WhatsApp Manager first. Guessing would burn Meta's limit of registration attempts.

Link an agent

A connected number stores inbound messages but stays silent until an agent is linked.

curl -X POST https://api.callmissed.com/api/v1/whatsapp/phone_numbers/9c2b7e30-1d8a-4c5f-9b3d-2f4a6e8b1c2d/link-bot \
  -H "Authorization: Bearer cm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{ "bot_id": "0a1b2c3d-4e5f-6a7b-8c9d-0e1f2a3b4c5d" }'

See Phone numbers for linking, pausing auto-reply, refreshing metadata from Meta, disconnecting and deleting.

Let AI write the first setup

Two endpoints turn a description of your business into a working agent. Both are billed to your workspace.

Bootstrap the whole number

POST /api/v1/whatsapp/ai/bootstrap · scope whatsapp:write

Generates a system prompt, a persona, a welcome message and a set of starter templates from a plain-language description, and optionally applies them to the number's agent.

Field	Type	Required	Notes
`phone_number_id`	UUID	Yes	The CallMissed phone id, from `GET /phone_numbers`
`company_description`	string, 10 to 2000 chars	Yes	What the business does and how it wants to sound
`mode`	enum	No	`suggest`, `auto_apply` or `autonomous`. Default `auto_apply`
`language`	string, 2 to 8 chars	No	Default `en`

suggest changes nothing and returns the plan for review. auto_apply and autonomous write the system prompt and create the templates.

curl -X POST https://api.callmissed.com/api/v1/whatsapp/ai/bootstrap \
  -H "Authorization: Bearer cm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "phone_number_id": "9c2b7e30-1d8a-4c5f-9b3d-2f4a6e8b1c2d",
    "company_description": "Acme Coffee is an Indian D2C roastery. We sell single-origin beans by subscription, ship in 2 to 3 days, and get asked about order status, roast dates and returns.",
    "mode": "suggest",
    "language": "en"
  }'

Response (200 OK)

{
  "bootstrap_id": null,
  "mode": "suggest",
  "applied": false,
  "system_prompt": "You are the support agent for Acme Coffee, an Indian D2C roastery...",
  "persona": {
    "name": "Acme Coffee Support",
    "tone": "warm and concise",
    "signature": "Acme Coffee"
  },
  "welcome_message": "Hi, this is Acme Coffee. Ask me about an order, a roast date, or a return.",
  "templates": [
    {
      "name": "order_shipped",
      "category": "UTILITY",
      "body": "Hi {{1}}, order {{2}} shipped today and should arrive in 2 to 3 days.",
      "applied": false,
      "template_id": null
    }
  ]
}

Field	Type	Notes
`bootstrap_id`	UUID, nullable	Present when the plan was applied. Pass it to undo
`mode`	string	Echoes the requested mode
`applied`	boolean	Whether the plan was written to the agent
`system_prompt`	string	The generated prompt
`persona`	object	`name`, `tone` and `signature`
`welcome_message`	string	Suggested opening line
`templates[]`	array	Each with `name`, `category`, `body`, `applied` and `template_id` when created

400 when the plan cannot be applied, for example the number does not exist. 422 when the model cannot produce a usable plan.

Undo a bootstrap

POST /api/v1/whatsapp/ai/bootstrap/{bootstrap_id}/undo · scope whatsapp:write

No body. Restores the agent's previous system prompt and removes the still-pending templates the bootstrap created, within a 7-day window. Templates Meta has already approved are kept, because deleting them would break sends already relying on them.

curl -X POST https://api.callmissed.com/api/v1/whatsapp/ai/bootstrap/7b3c9d10-2e4f-4a5b-8c6d-9e0f1a2b3c4d/undo \
  -H "Authorization: Bearer cm_your_api_key"

Response (200 OK)

{
  "undone": true,
  "reverted_at": "2026-04-19T12:44:03+00:00",
  "reason": "ok"
}

Field	Type	Notes
`undone`	boolean	Whether anything was reverted
`reverted_at`	string, nullable	ISO 8601 timestamp of the revert, `null` when nothing was reverted
`reason`	string	`ok` on success. Otherwise `bootstrap_id not found` or `undo window expired`

A refusal is still a 200: read undone, not the status code.

Write or improve a system prompt

POST /api/v1/whatsapp/ai/build_system_prompt · scope whatsapp:write

Read-only. Returns markdown you review and save on the agent yourself.

Field	Type	Required	Notes
`intent`	string, 10 to 8000 chars	Yes	The business and what the agent should do
`language`	string, 2 to 8 chars	No	Default `en`
`tone`	string, max 40	No	For example `friendly`, `formal`
`existing_prompt`	string, max 8000	No	Set this to improve an existing prompt instead of starting fresh

curl -X POST https://api.callmissed.com/api/v1/whatsapp/ai/build_system_prompt \
  -H "Authorization: Bearer cm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "intent": "Support agent for Acme Coffee. Handle order status, roast dates and returns. Escalate anything about a refund over 5000 rupees to a human.",
    "tone": "warm and concise"
  }'

Response (200 OK)

{
  "system_prompt": "## Role\nYou are the support agent for Acme Coffee...\n\n## Rules\n- Answer in under 60 words..."
}

422 when the model cannot produce a usable prompt. Shorten or clarify the intent and retry.

To draft message templates the same way, see Draft a template with AI.

Verify it works

Message your business number from a personal WhatsApp account. Then:

GET /api/v1/whatsapp/webhook_events shows the raw event arriving with signature_valid: true.
Your own webhook subscription receives a message.received event. See Inbound events.
The agent replies, and the thread appears in the dashboard inbox.

If the message arrives but nothing replies, walk the auto-reply checklist. The usual cause is a number that was never linked to a bot.

Going to production. While your number is in Meta's test mode you can only message numbers you have added as recipients. Submit your business for verification and request production access in the Meta dashboard to message any customer who opts in. Sends also fail until Meta approves a display name for the number, which shows as name_status on the phone-number object.

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