Overview

A Chargeback's Evidences/Materials can be uploaded to the Pay1st gateway after receiving the Chargeback Webhook Notification. This API is a POST request that allows the Pay1st Partner to upload evidence documents.

Pre Requisites

An access token needs to be generated in order to use this API (see Authentication - Generate Access Token)
Note that the maximum number of evidences allowed per chargeback is 10

API Description

HTTP Headers

Header Name	Description
AccessToken	This is the `Access Token` field returned from the Authentication - Generate Access Token response. This should be in the format `Bearer <AccessToken>`
Accept	`application/vnd.carry1st.payments.chargeback+json`
Content-Type	`multipart/form-data`

URL Format

POST https://<payments_url>/api/pay1st/transactions/chargebacks/<chargeback-reference>/evidences

POST Parameters (in form-data format)

Field Name Mandatory Notes

file

Field Name	Mandatory	Notes
file	Y	The file to upload. The following file formats are supported: `application/pdf, image/jpeg, image/png`. The maximum file size allowed is 20MB.

The file to upload.

The following file formats are supported: application/pdf, image/jpeg, image/png.

The maximum file size allowed is 20MB.

Success Response

Valid HTTP Success Status Codes:

HTTP Status Code	Name	Description
201	Success	This indicates that the request has been successful.
400	Bad Request	An invalid `AccessToken`might be used

HTTP Response Body:

{
    "id": 16,
    "uploadReference": "C-6AXW4ECL62QHZZL4TB2-CE",
    "chargebackReference": "C-ICYFKBQAFJ85A08XOU5-C",
    "fileName": "proof-of-transaction.png",
    "contentType": "image/png",
    "fileSizeBytes": 98405,
    "source": "MERCHANT_UPLOAD",
    "uploadedByPartnerCode": "SHOP",
    "uploadedAt": "2026-Jun-03 11:05:24",
    "status": "ACTIVE"
}

HTTP Response Fields

Name	Type	Description
id	Number	The unique identifier for this evidence
uploadReference	String	The Pay1st upload reference for this evidence
fileName	String	The filename of the evidence
contentType	String	The mime type of the evidence
fileSizeBytes	Number	The file size of the evidence in bytes
source	String	This will always return `MERCHANT_UPLOAD`
uploadedByPartnerCode	String	The Pay1st Partner code that represents the account that uploaded this evidence
uploadedByAdminUserId	String	If materials are uploaded using the Pay1st console, then this is uploaded with the Admin User Identifier that performed the upload
uploadedAt	String	The date when the evidence was uploaded
status	String	The status of the evidence. Possible values are `ACTIVE, DELETED`

Error Response

See Handling Error Codes for more details on handling error responses.