> For the complete documentation index, see [llms.txt](https://docs.payments.thalescloud.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.payments.thalescloud.io/d1-v1-api/migrate-your-d1-integration.md).

# Migrate your D1 integration

Understand what changes between D1 API v1 and v2 and how to migrate safely.

D1 provides two generations of the D1 API:

* **v1** APIs use `/v1/` in the URL path.
* **v2** APIs use `/v2/` in the URL path.

v2 is the recommended option for new integrations.\
It also introduces new capabilities and updated models for end user and card management.

## When you should migrate

Migrate if your issuer backend currently calls v1 endpoints and you want to:

* Use v2-only features (for example, new authorization controls).
* Align with the latest D1 API models for end user and card lifecycle operations.
* Standardize on a single API version for new and existing cards.

{% hint style="info" %}
The D1 API uses the term **consumer** for an end user.\
This documentation uses **end user**, and keeps API field names as-is (for example, `consumerId`).
{% endhint %}

## Recommended migration approach

Use the guided v1-to-v2 migration flow:

* Follow [Migrate to v2](/d1-v1-api/migrate-to-d1-api-v2.md) for the end-to-end steps.
* Route **new registrations** to v2 first.
* Migrate existing data (handled by Thales).
* Then move lifecycle traffic (suspend, resume, renew, replace, delete) to v2.

## Related guides

* [Register end users and cards](/d1-v1-api/register-end-users-and-cards-in-d1.md)
* [Manage end user and cards](/d1-v1-api/manage-end-users-and-cards.md)

## API references

* [D1 v1 API references](/d1-v1-api/d1-v1-api-references.md)


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