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Refund API

Humm provides an API to programmatically process refunds or adjustments to an humm purchase.

Humm Endpoints

Humm Environment URL
Production Endpoint
Sandbox Endpoint



Key Value
Content-Type application/json


    "x_merchant_number": "30199250",
    "x_purchase_number": "52004168",
    "x_amount": "10.00",
    "x_reason": "Test refund",
    "signature": "e39ae5f3233f561162836989e050c1b61ba9e3d5eb3d64d4b3701e95fb5850a1"

See Signature Generation for information on how to generate the HMAC Signature.


HTTP Status Reason Code Reason Description
204 none Success
400 MERR0001 API Key Not found
400 MERR0003 Refund Failed
400 MERR0004 Invalid Request
401 none Failed Signature Check


The following curl command will allow you to test the refunds API. You will need to substitute your x_merchant_number, x_purchase_number and signature

curl \
--header "Content-Type:application/json" \
--request POST \
--data '{
    "x_merchant_number": "30199250",
    "x_purchase_number": "52000152",  
    "x_amount": 45.00,
    "x_reason": "test",
    "signature": "a5fc92ddd2326c6099bd0f43bbe75afb54004a6ba68f354cc2b40328341d8ee2"
}' \