# Custom connector

Custom connectors let The Wallet Crew integrate with systems that do not have a native connector. They are useful when a Brand or partner needs to fetch external data, react to wallet lifecycle events, or route transactional emails through an internal delivery stack.

<details>

<summary><strong>Real-world examples</strong></summary>

* A Brand enriches a loyalty pass with points, tier, or profile data from a CRM.
* A team synchronizes pass installation status with a marketing, analytics, or BI platform.
* A partner keeps The Wallet Crew email rendering, but sends through its own gateway.

</details>

## What this section covers

This section groups the custom connector patterns that are used most often in delivery projects.

### Pass lifecycle hooks

Use this pattern when an external system must react to wallet installation changes.

Typical use cases include CRM synchronization, install-based segmentation, onboarding journeys, and uninstall tracking.

* [Pass installation and uninstallation hooks](/connect/custom-connector/installation-changed-extensibility.md)

### Script-based email delivery

Use this pattern when The Wallet Crew should still build the email content, but the final send must be handled by a provider or relay controlled outside The Wallet Crew.

This is useful for internal gateways, unsupported ESPs, or environments with strict delivery governance.

* [EmailSender extensibility](/connect/custom-connector/emailsender-extensibility.md)

### Generic runtime scripting

Some custom connectors also need a broader runtime script to enrich pass data or register custom provider logic.

That generic model is documented in the developer guide:

* [Custom connector guide](/develop/guides/custom-connector.md)

## When to use a custom connector

Use a custom connector when the integration needs are specific enough that a built-in connector would not fit cleanly.

* Use a built-in connector when one already exists for the target platform.
* Use a custom connector when logic must call a private API or internal relay.
* Use a custom connector when runtime behavior must react to pass lifecycle events.

## FAQ

<details>

<summary><strong>When should a built-in connector be used instead?</strong></summary>

Use a built-in connector when The Wallet Crew already supports the target platform and the expected workflow matches the project needs. Use a custom connector when the integration depends on private APIs, internal relays, or runtime-specific logic.

</details>

<details>

<summary><strong>Is this the right place for install and uninstall synchronization?</strong></summary>

Yes. For wallet installation lifecycle events, start with [Pass installation and uninstallation hooks](/connect/custom-connector/installation-changed-extensibility.md).

</details>

<details>

<summary><strong>Is this the right place for a custom email gateway?</strong></summary>

Yes. For script-based transactional email sending, use [EmailSender extensibility](/connect/custom-connector/emailsender-extensibility.md).

</details>

<details>

<summary><strong>Where is the generic custom connector scripting model documented?</strong></summary>

The broader runtime model is covered in the [Custom connector guide](/develop/guides/custom-connector.md). This page focuses on the connector entry points exposed in the **Connect** section.

</details>


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