**With Papo (https://papo.global/), you can use the REST API to send approved WhatsApp message templates (HSM), automating transactional notifications and campaigns without accessing the interface. The API allows you to list the Cloud API inboxes in your account, retrieve templates approved by Meta, and send them to one or multiple contacts, as long as you have an API token and the templates are synced in the platform.**

| API action | What it does | Example use |
| :--- | :--- | :--- |
| List WhatsApp inboxes | Returns the WhatsApp Cloud API inboxes associated with the account | Select the correct inbox before sending |
| List approved templates | Returns the message templates (HSM) with “approved” status for a given inbox | Check the HSMs available for sending |
| Send HSM to one contact | Sends an approved template to a single phone number, filling in the variables | Order notification, appointment reminder |
| Send HSM to multiple contacts | Sends the same template to a list of contacts at once | Marketing campaign, mass announcement |

## How HSM sending works via the API

The Papo API mirrors the platform's features. To send a WhatsApp message template, you don't need to create anything new via code: templates are created and submitted directly in Meta Business Manager and, once approved, appear automatically in your Papo account. The API only queries the list of approved templates and performs the send.

The typical integration flow consists of:
1. Generate an API token in the Papo dashboard.
2. Identify the WhatsApp Cloud API inbox where the template was synced.
3. Get the list of approved templates (HSM) from that inbox.
4. Prepare the request with the necessary parameters: template ID, language, recipient number with country code, and variable values (if the template contains `{{1}}`, `{{2}}`, etc.).
5. Send the request — either to a single contact or to a set of numbers, each with its own custom variables.

## Step by step to use the API

### 1. Generate an API token
In your Papo account settings menu, go to the API or access tokens section. Create a token with the permissions needed to manage conversations and messages. Store the token in a safe place; it will be sent in the header of all requests.

### 2. List the available WhatsApp inboxes
Before sending any template, you need to know which inbox contains the approved templates. Use the endpoint that returns your account's WhatsApp Cloud API inboxes. Note the identifier of the inbox you intend to use — it will be required in the following steps.

### 3. Check the approved templates (HSM)
With the inbox identifier in hand, call the endpoint that lists templates with `APPROVED` status. The response will bring, for each template, the name, available language, category (Marketing, Utility, or Authentication), and expected parameters. This step is important to confirm that the template is released and to know which variables to fill in.

### 4. Build the send request
The send operation for a single contact basically requires:
- The template ID (or name, depending on the implementation).
- The template language (for example, `pt_BR`).
- The contact's phone number, including the country code (e.g., `5511999999999`).
- An object with the variable values, if the template contains placeholders.

For batch sending (multiple contacts), the call accepts a list of recipients, each with its number and, optionally, its own variables. The template is the same for everyone.

### 5. Send and check the response
The API returns a synchronous confirmation that the send request was accepted. To track the real delivery status (delivered, read, failed), you can configure an outbound webhook — Papo notifies conversation events in real time. The article about receiving real-time events (listed in “Read also”) explains how to enable this feature.

## Who should use the API to send HSM

Any business that wants to automate transactional communications from external systems benefits from the API. Instead of relying on the Papo interface for each notification, you can integrate sending directly into your ERP, CRM, or e-commerce platform. Common examples:
- Purchase confirmation or order status update.
- Appointment or scheduling reminder sent 24 hours in advance.
- Overdue invoice collection with the payment link.
- Flight or reservation change communication.

The API is especially useful when the rule that determines **when** to send the template lives in another software — for example, a logistics system that triggers the delivery notification as soon as the package goes out for transport.

## Frequently asked questions

### Does the Papo API have an additional cost?
The API is available in Papo plans. You can generate tokens and use the endpoints according to your plan. Details on limits and per-request fees are on the plans page and in the API documentation.

### Do I need to create message templates via the API?
No. Templates must be created and submitted for approval in Meta Business Manager. Once approved, they are automatically synced in Papo and appear in the API template listing.

### Can I send HSM to numbers that are not in Papo's CRM?
Yes. The recipient does not need to be previously registered in the platform's CRM. Just provide the WhatsApp number (with country code and area code) in the request. However, you must have the customer's consent (opt-in) to receive the communication, especially if the template is in the Marketing category.

### How do I know if the message was delivered?
The API's immediate response confirms that the request was accepted and sent to WhatsApp. To monitor failures, deliveries, and reads in real time, you need to enable Papo's event webhook (outbound). See the webhooks guide in the help center.

### Is there a rate limit for API sends?
Yes. Papo applies rate limits to protect service stability and comply with WhatsApp policies. It is recommended to keep moderate speeds — avoiding sudden spikes helps preserve the health of the number. The exact values are in the API documentation.

### Can I use the API for mass marketing campaigns?
Yes, as long as you use only approved templates in the Marketing category and have explicit opt-in from recipients. Sending unwanted messages can generate reports and put your number at risk of being blocked. Plan sends with cadence control and always respect WhatsApp policies.

## Read also

- [How to receive real-time events from Papo via Webhook (outbound)](/hc/papo/articles/how-to-receive-real-time-events-from-papo-via-webhook-outbound)
- [How to use Papo's API to create and update contacts in bulk](/hc/papo/articles/how-to-use-papo-api-to-create-and-update-contacts-in-bulk)

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