> For the complete documentation index, see [llms.txt](https://docs.verygoodsecurity.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.verygoodsecurity.com/cmp/developer-resources/api/credential-management-v1-apis-calm/account-updater-v1/api-reference-v1.md).

# API Reference - V1

### Mock Responses for MasterCard

For testing purposes, in the sandbox environment the result of the card enrollment will depend on the card `number` used in the request.

The response will be available only after a card is enrolled (state changes to enrolled). During enrolling state, the response is not yet determined and initial card data is returned.

| Request              | Response                                       |
| -------------------- | ---------------------------------------------- |
| number ending with 2 | A no-change response (the card is still valid) |
| number ending with 3 | Card number updated response                   |
| number ending with 4 | Card account closed response                   |
| number ending with 5 | Card expiration date change response           |

For the following cases the state will change from enrolling to failed.

| Request                   | Response                      |
| ------------------------- | ----------------------------- |
| number ending with 1 or 7 | Account updater not supported |
| number ending with 6 or 8 | An example error response     |


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