openapi: 3.1.0
info:
  title: Paytm Payment Gateway Payments Refunds API
  description: Server-to-server REST APIs for Paytm Payment Gateway integrations. Covers transaction initiation (returning a txnToken used by checkout SDKs), transaction processing for selected payment modes, and refund initiation. Requests are signed via Paytm's checksum logic and the signature is sent in the request head.
  version: '1.0'
  contact:
    name: Paytm for Business
    url: https://business.paytm.com/docs/api/
servers:
- url: https://securegw.paytm.in
  description: Production
- url: https://securegw-stage.paytm.in
  description: Staging
- url: https://secure.paytmpayments.com
  description: Production (paytmpayments.com host)
- url: https://securestage.paytmpayments.com
  description: Staging (paytmpayments.com host)
security: []
tags:
- name: Refunds
paths:
  /refund/apply:
    post:
      tags:
      - Refunds
      summary: Initiate refund
      description: Initiates a refund (full or partial) for a completed Paytm transaction. Refunds are asynchronous; success of this call only acknowledges registration.
      operationId: initiateRefund
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                head:
                  type: object
                  properties:
                    signature:
                      type: string
                body:
                  type: object
                  required:
                  - mid
                  - orderId
                  - refId
                  - txnId
                  - txnType
                  - refundAmount
                  properties:
                    mid:
                      type: string
                    orderId:
                      type: string
                    refId:
                      type: string
                      description: Merchant-generated unique refund reference.
                    txnId:
                      type: string
                      description: Paytm payment transaction id being refunded.
                    txnType:
                      type: string
                      enum:
                      - REFUND
                    refundAmount:
                      type: string
                      description: Up to 2 decimal places.
      responses:
        '200':
          description: Refund registered.
components:
  securitySchemes:
    paytmChecksum:
      type: apiKey
      in: header
      name: signature
      description: Checksum signature computed over the request body using Paytm's merchant key. Carried in the request head.signature property and/or as a request header per endpoint guidance.