# Setup

{% stepper %}
{% step %}
**Create your channel**

Go to **Settings** > **Accounts** > **Add account** > **Custom** *(Build your own)*. Choose whether the account should be shared or personal - this can be changed later, so we recommend starting with a personal account and sharing it when ready.

You should now see a configuration screen like this:

<div data-with-frame="true"><img src="https://content.gitbook.com/content/egxqkD7AXM4n11rNf5qI/blobs/NGkQDdlUxogKtHx7WPBO/settings%202245cb29635c708dbf1ded02e23f187bafa96d5b331469e613cd86a483029d23.png" alt="" width="563"></div>

Here are details on each of these settings:

**Account name**

This name is used in your **Accounts** setting to identify the custom channel. It can be changed later on.

<div data-with-frame="true"><img src="https://content.gitbook.com/content/egxqkD7AXM4n11rNf5qI/blobs/Sp7tzYuqBF3AZc2PaFrw/account%20name%20c36ee0c9a4737f67729703f66236467f2da7c54dcf3189440b9ce97f5d138edb.png" alt="" width="563"></div>

**Message type**

Custom channels support three different message types.

<div data-with-frame="true"><img src="https://content.gitbook.com/content/egxqkD7AXM4n11rNf5qI/blobs/TiIcQyeS31Aj5omkidQ6/message%20type%203eee6c5ae0fb3e1e0b05820e100d078a8d250570944d8113a32f088313762bc5.png" alt="" width="563"></div>

Here are the main differences between the three types:

| Functionalities                                                                           | Text | HTML | Email |
| ----------------------------------------------------------------------------------------- | ---: | ---: | ----: |
| <p>Allow replies (via custom channel webhook)<br>Fields: From, To</p>                     |    ✅ |    ✅ |       |
| <p>Allow replies (via existing email accounts)<br>Fields: From, To, Cc, Bcc, Reply-To</p> |      |      |     ✅ |
| Rich-text (HTML)                                                                          |      |    ✅ |     ✅ |
| Basic text + emojis                                                                       |    ✅ |      |       |
| Bubble color                                                                              |    ✅ |      |       |
| Attachments                                                                               |    ✅ |    ✅ |     ✅ |

Once your custom channel is created, you **cannot update its message type**.

**Outgoing messages**

The following settings apply only to the **Text** or **HTML** message types.

You can define whether Missive allows users to send new messages, reply to existing messages or edit recipients of a reply.

<div data-with-frame="true"><img src="https://content.gitbook.com/content/egxqkD7AXM4n11rNf5qI/blobs/aOCbZMGZm9VNi9IWxWa2/outgoing%20messages%20ef1fe45047daa0e72b4baa62b840940b7bfb0caf7910eb1c63389fa0b2dda2db.png" alt="" width="563"></div>

**Aliases**

When you reply to custom channel messages or create new messages, Missive lets you select one of the pre-defined aliases you've defined in this section. An alias can be composed of three keys: `id`, `name` and `username`. Your outgoing webhook may use these in any way. They are all optional, so feel free to uncheck those you won’t use:

* Allow defining recipient ID
* Allow defining recipient name
* Allow defining recipient username

You must also define the maximum number of recipients new messages and replies can have.

**Webhooks**

Go to the "Send messages" step for details on the webhook options.
{% endstep %}

{% step %}
**Receive messages**

To create incoming messages in your custom channel, you must use the Missive API. Learn how to [get started](https://missiveapp.com/docs/developers/rest-api) and how to [create messages](https://missiveapp.com/docs/developers/rest-api/endpoints#create-message) in your channel using the `POST /messages` endpoint.

You must pass your channel ID when creating messages. You can find it under **Account ID** once your channel has been created.

<div data-with-frame="true"><img src="https://content.gitbook.com/content/egxqkD7AXM4n11rNf5qI/blobs/Gu8xObpk880lTXdVWLXC/account_id%20136a703768ff346070ca34ba3bd9700981adbd654688908f5b31babede85ed14.png" alt="" width="563"></div>
{% endstep %}

{% step %}
**Send messages**

To send messages via the custom channel, you must define a webhook URL endpoint. Every time you send a message from Missive, the associated payload will be posted to this endpoint.

<div data-with-frame="true"><img src="https://content.gitbook.com/content/egxqkD7AXM4n11rNf5qI/blobs/XcF7ADn9rWyUu8pse8T2/webhook%20b38503f594024506efd3d804016f87271b55ad2268b5f06ead78530af41b88c5.png" alt="" width="563"></div>

The request payload looks like this:

{% code title="webhook payload.json" %}

```json
{
  "message": {
    "id": "a8ae9822-ec20-4cc7-989f-4ff4bc473cfe",
    "preview": "Hi, my name is Phil! How can I help you?",
    "type": "custom_text",
    "delivered_at": 1623269628,
    "updated_at": 1623269628,
    "created_at": 1623269608,
    "references": [],
    "body": "Hi, my name is Phil! How can I help you?",
    "from_field": {
      "id": null,
      "name": "My custom account",
      "username": "My custom account"
    },
    "to_fields": [
      {
        "id": "12345",
        "name": "Philippe Lehoux",
        "username": "@plehoux"
      }
    ],
    "external_id": null,
    "attachments": [],
    "author": {
      "id": "af577bfa-076f-4ff0-bcc0-9b2d578fc601",
      "email": "philippe@conferencebadge.com",
      "name": "Philippe Lehoux",
      "avatar_url": "https://missive.cdn.com/814942a3-ae65-4da5-b1ab-bd5266336ef4/philippe.png"
    }
  },
  "conversation": {
    "id": "15ff3085-4654-488d-a18f-aced2cc7dcc9",
    "subject": null,
    "latest_message_subject": "Message from Philippe Lehoux",
    "organization": null,
    "color": null,
    "assignees": [],
    "users": [
      {
        "id": "af577bfa-076f-4ff0-bcc0-9b2d578fc601",
        "name": "Philippe Lehoux",
        "email": "philippe@conferencebadge.com",
        "unassigned": false,
        "closed": false,
        "archived": false,
        "trashed": false,
        "junked": false,
        "assigned": false,
        "flagged": false,
        "snoozed": false
      }
    ],
    "attachments_count": 0,
    "messages_count": 2,
    "authors": [
      {
        "name": "My custom account",
        "address": null
      },
      {
        "name": "Philippe Lehoux",
        "address": null
      }
    ],
    "drafts_count": 0,
    "send_later_messages_count": 0,
    "tasks_count": 0,
    "completed_tasks_count": 0,
    "web_url": "https://mail.missiveapp.com/#inbox/conversations/15ff3085-4654-488d-a18f-aced2cc7dcc9",
    "app_url": "missive://mail.missiveapp.com/#inbox/conversations/15ff3085-4654-488d-a18f-aced2cc7dcc9",
    "assignee_names": "",
    "assignee_emails": "",
    "shared_label_names": "",
    "shared_labels": []
  }
}
```

{% endcode %}

Your server is responsible for processing this payload as needed, like creating / sending a message via a third-party API of your choice, etc.

**Signature secret (validating webhook requests)**

If a signature secret is defined in your custom channel settings, all webhook requests will include a `X-Hook-Signature` hash signature of the payload. With this signature, you can validate that the request is coming from Missive. To do so, you must compute the signature yourself and compare it to the one provided in the request header.

The signature starts with `sha256=` followed by a HMAC hexdigest. Here's sample code showing how to compute the signature in Ruby:

{% code title="compute signature (Ruby)" %}

```ruby
#
# `secret` is the "Signature secret" set in your custom channel settings.
# `request_body` is the full HTTP request body.
#
computed_signature = 'sha256=' + OpenSSL::HMAC.hexdigest(
  OpenSSL::Digest.new('sha256'), secret, request_body
)
```

{% endcode %}

Make sure to assess equality between the header signature and the one you've computed using a method that prevents timing attacks against regular equality operators. In Ruby, you can use secure\_compare:

{% code title="secure compare (Ruby)" %}

```ruby
valid = Rack::Utils.secure_compare(x_hook_signature, computed_signature)
```

{% endcode %}
{% endstep %}
{% endstepper %}

Need more specific answers? [Contact us](https://missiveapp.com/docs/developers/contact)