# ThreeDSecureChallengeDto

A model the API reference uses in a request or a response. The operation pages link every field typed as this model here.

The parameters a caller posts to the issuer's access control server to present a challenge:
an HTML form targeting `acsUrl` carrying `encodedChallengeRequest` as
`creq` and, when present, `sessionData` as `threeDSSessionData`.

## Fields
- `acsUrl` (string): The access control server URL the challenge form posts to. (nullable)
- `encodedChallengeRequest` (string): The encoded challenge request to post as the `creq` field. (nullable)
- `sessionData` (string): The session data to post as `threeDSSessionData`, when the vendor supplies one. (nullable)
- `challengeWindowSize` ([ThreeDSChallengeWindowSize](https://devportal.signapay-sbx.winkpg.io/docs/api/models/ThreeDSChallengeWindowSize.md)): The window size the challenge request declared.
  Values:
  - `Size250X400`: Wire value 01: 250 x 400.
  - `Size390X400`: Wire value 02: 390 x 400.
  - `Size500X600`: Wire value 03: 500 x 600.
  - `Size600X400`: Wire value 04: 600 x 400.
  - `FullScreen`: Wire value 05: full screen.
- `acsTransactionId` (string): The access control server transaction id, for the caller's own correlation. (nullable)

## See also

- [All documentation](https://devportal.signapay-sbx.winkpg.io/llms.txt): the machine-readable index of every public page on this site.