> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abusix.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Subscriber resolving via X-Header

# Subscriber Resolving via X-Headers

Subscriber resolving is a **critical part** of setting up **AbuseHQ** as your automated abuse desk solution.

This guide explains how **Email Service Providers** or **Mailbox Providers** can use the power of **X-Headers** to handle subscriber resolution in **under 60 minutes**.

***

## Out-of-the-Box Support

AbuseHQ is preconfigured to understand the following **X-Header** without any additional setup:

**X-Header:**

> ***X-AbuseHQ-Resolve:***

The value of the Header needs to be in this form when you decide to use contracts:

> ***JSON***
>
> ```
> {
> "subscriber": {
> "id": "<subscriber_id>",
> "resolver_data": {
> "<subscriber_key1>": "<subscriber_value1>",
> "<subscriber_key2>": "<subscriber_value2>"`
> }
> },
> "contract": {
> "id": "<contractid>",
> "resolver_data": {
> "<contract_key1>": "<contract_value1>",
> "<contract_key2>": "<contract_value2>"
> }
> }
> }
> ```

 

and this way, when not using contracts:

> ***JSON***
>
> ```
> {
> "subscriber": {
> "id": "<subscriber_id>",
> "resolver_data": {
> "<subscriber_key1>": "<subscriber_value1>",
> "<subscriber_key2>": "<subscriber_value2>"
> }
> },
> "contract": {
> "id": "<contractid>",
> "resolver_data": {
> "<contract_key1>": "<contract_value1>",
> "<contract_key2>": "<contract_value2>"
> }
> }
> }
> ```

 

The number of **subscriber\_keys** and **contract\_keys** is not restricted, but we recommend only adding necessary ones and keeping the values as simple as possible.

The correct **JSON** part has to be encoded with **BASE64** and added as a value to the **X-Header**, which will end up looking like this:

> ```
> X-AbuseHQ-Resolve: ewoJInN1YnNjcmliZXIiOiB7CgkJImlkIjogIjxzdWJzY3JpYmVyX2lkPiIsCgkJInJlc29sdmVyX2RhdGEiOiB7CgkJCSI8c3Vic2NyaWJlcl9rZXkxPiI6ICI8c3Vic2NyaWJlcl92YWx1ZTE+IiwKCQkJIjxzdWJzY3JpYmVyX2tleTI+IjogIjxzdWJzY3JpYmVyX3ZhbHVlMj4iCgkJfQoJfSwKCSJjb250cmFjdCI6IHsKCQkiaWQiOiAiPGNvbnRyYWN0aWQ+IiwKCQkicmVzb2x2ZXJfZGF0YSI6IHsKCQkJIjxjb250cmFjdF9rZXkxPiI6ICI8Y29udHJhY3RfdmFsdWUxPiIsCgkJCSI8Y29udHJhY3Rfa2V5Mj4iOiAiPGNvbnRyYWN0X3ZhbHVlMj4iCgkJfQoJfQp9Cg==
> ```

 

Adding a header like this to **all outbound emails** will let **AbuseHQ** automatically do all the magic for you and will present you with the correct **Contract** and **Subscriber** information.