Testing MTN MoMo Collection API in Sandbox using Postman

Step-by-step guide on testing the MTN MoMo Collection API in a sandbox environment using Postman. It explains how to create an API User and API Key using a unique X-Reference-Id and subscription key, then generate a Bearer Token that expires hourly. Finally, it details how to configure and send a POST RequestToPay request using the token, a new transaction ID, and the sandbox target environment.

To create an API User, you need the following things in place: X-Reference-Id and Ocp-Apim-Subscription-Key 1. X-Reference-Id This is used as User ID since the Sandbox is a Mock Environment so we kinda create our own ids and send them over to the sandbox so it can uniquely identify the user If all went well, you should get the response with "Status: 201 Created" You will not see any other additional content in the response body, just that message is good enough So this means you have created an API User with an ID:9f92971b-cd2e-4feb-9053-0b14d53ac4f5 this is the same id you supplied, nothing special about it Take note of this ID as it will be used to create the API Key in step 2 and API Bearer Token in step 3 If all went well, you should get the response with "Status: 201 Created" You will also see additional content in the response body, as shown below: { "apiKey": "1e89774dabd944b4b112c30aaef5b9c8" } So this means you have created an API Key with value:1e89774dabd944b4b112c30aaef5b9c8 Take note of this API Key value 1e89774dabd944b4b112c30aaef5b9c8 as it will be used as PASSWORD, while the User ID/X-Reference-Id 9f92971b-cd2e-4feb-9053-0b14d53ac4f5 will be used as USERNAME when creating the Bearer Token in Step 3. So this means you have created a Bearer Token Access Token with value:eyJ0eXAiOiJKV1QiLCJhbGciOiJSMjU2In0.eyJjbGllbnRJZCI6ImM0ZjZkMzNkLWVhNzYtNDYwOS1iODE2LWE5OWRjODAxYjUzMiIsImV4cGlyZXMiOiIyMDIwLTA2LTA5VDIwOjMyOjQyLjIwMSIsInNlc3Npb25JZCI6IjZkYjg0MjIxLWM4ZWQtNGZhZC1hMDM5LWYzZDY3YzNjMzMwMiJ9.FUhqzW HhXlOIsYu3YQMWsfpBujSktAldnnh70De8uKuuPGGlgIEmIrakQ91klV8rNeD2g tq9nOR748j8O-vp5oNKDmmt5ANo2qUoYZTaiwSthev6DQ2TLvxr45w4QCX0YmPTDtkue 9R7ZpnEhud51XlKfEOEMAZhdWoVDvL08xrwrL-yP2yfLGRZVtZfpaqrx7CxgUO3MT zXy8QuvHAvlwlgxIvkZhILdTbycyZHAtvRCeoMJ0G7REsQQYHfNNm87aXg9vwcjDu-YZGVaA27jHP2z-l4gbeg-sluoqafcQ8YwqPZ4nGcAMoMCTU6wtUICDMNw-qWpZwlHEixaw Take note that this token expires in 1 hour. So it means you will need to send this request every after 1 hour to get a fresh token, if you have to continue testing api calls on the rest of the endpoints. Take note of this value as it will be used in subsequent api calls in Step 4 and Step 5 To successfully send this POST RequestToPay request, you need the following things in place: X-Reference-Id Transaction ID , Ocp-Apim-Subscription-Key, X-Target-Environment and the Bearer Token 1. X-Reference-Id Transaction ID Note that the X-Reference-id used here should not be the same as one used in Step 1 to 3. The X-Reference-Id used here represents the Transaction ID for our request to pay, in the Mock Environment Sandbox So we will need to GENERATE a NEW ID for this transaction In our example we will use b988a090-bbeb-46af-806c-db7fd8aeca7e Remember, this is treated as Transaction ID 2. Ocp-Apim-Subscription-Key Get the Primary or Secondary Subscription Key of the Collections Subscription from your Profile In our example we used b44728c249c24d8bb11d8b8592f4f5a7 so we will use this same value here too 3. X-Target-Environment -Put the value as "sandbox" 4. Bearer Token Use the Bearer Token we created in Step 3: Create Bearer Token In our example, the Bearer Token is : eyJ0eXAiOiJKV1QiLCJhbGciOiJSMjU2In0.eyJjbGllbnRJZCI6ImM0ZjZkMzNkLWVhNzYtNDYwOS1iODE2LWE5OWRjODAxYjUzMiIsImV4cGlyZXMiOiIyMDIwLTA2LTA5VDIwOjMyOjQyLjIwMSIsInNlc3Npb25JZCI6IjZkYjg0MjIxLWM4ZWQtNGZhZC1hMDM5LWYzZDY3YzNjMzMwMiJ9.FUhqzW HhXlOIsYu3YQMWsfpBujSktAldnnh70De8uKuuPGGlgIEmIrakQ91klV8rNeD2g tq9nOR748j8O-vp5oNKDmmt5ANo2qUoYZTaiwSthev6DQ2TLvxr45w4QCX0YmPTDtkue 9R7ZpnEhud51XlKfEOEMAZhdWoVDvL08xrwrL-yP2yfLGRZVtZfpaqrx7CxgUO3MT zXy8QuvHAvlwlgxIvkZhILdTbycyZHAtvRCeoMJ0G7REsQQYHfNNm87aXg9vwcjDu-YZGVaA27jHP2z-l4gbeg-sluoqafcQ8YwqPZ4nGcAMoMCTU6wtUICDMNw-qWpZwlHEixaw B. Configure Postman 1. URL POST https://sandbox.momodeveloper.mtn.com/collection/v1 0/requesttopay 2. Params DO NOT PUT ANYTHING HERE 3. Authorization Select "Bearer Token" as Type In the Token field, put the Bearer Token created in Step 3 In our example, configuration for this should look like below: To successfully send this GET RequestToPay request, you need the following things in place: X-Reference-Id Transaction ID , Ocp-Apim-Subscription-Key, X-Target-Environment and the Bearer Token 1. X-Reference-Id Transaction ID Use the X-Reference-id used in step 4 when creating the RequestToPay Trasaction In our example we used b988a090-bbeb-46af-806c-db7fd8aeca7e so we will use the same id here too Remember, this is treated as Transaction ID 2. Ocp-Apim-Subscription-Key Use the same Primary or Secondary Subscription Key you used during Step 1: Create API User In our example we used b44728c249c24d8bb11d8b8592f4f5a7 so we will use this same value here too 3. X-Target-Environment Put the value as "sandbox" 4. Bearer Token Use the Bearer Token we created in Step 3: Create Bearer Token In our example, the Bearer Token is :eyJ0eXAiOiJKV1QiLCJhbGciOiJSMjU2In0.eyJjbGllbnRJZCI6ImM0ZjZkMzNkLWVhNzYtNDYwOS1iODE2LWE5OWRjODAxYjUzMiIsImV4cGlyZXMiOiIyMDIwLTA2LTA5VDIwOjMyOjQyLjIwMSIsInNlc3Npb25JZCI6IjZkYjg0MjIxLWM4ZWQtNGZhZC1hMDM5LWYzZDY3YzNjMzMwMiJ9.FUhqzW HhXlOIsYu3YQMWsfpBujSktAldnnh70De8uKuuPGGlgIEmIrakQ91klV8rNeD2g tq9nOR748j8O-vp5oNKDmmt5ANo2qUoYZTaiwSthev6DQ2TLvxr45w4QCX0YmPTDtkue 9R7ZpnEhud51XlKfEOEMAZhdWoVDvL08xrwrL-yP2yfLGRZVtZfpaqrx7CxgUO3MT zXy8QuvHAvlwlgxIvkZhILdTbycyZHAtvRCeoMJ0G7REsQQYHfNNm87aXg9vwcjDu-YZGVaA27jHP2z-l4gbeg-sluoqafcQ8YwqPZ4nGcAMoMCTU6wtUICDMNw-qWpZwlHEixaw B. Configure Postman 1. URL GET https://sandbox.momodeveloper.mtn.com/collection/v1 0/requesttopay/b988a090-bbeb-46af-806c-db7fd8aeca7e 2. Params DO NOT PUT ANYTHING HERE 3. Authorization Select "Bearer Token" as Type In the Token field, put the Bearer Token created in Step 3 In our example, configuration for this should look like below: So this means your RequestToPay Transaction was approved by the Payer NOTE: -If the phone number used as PartyId, during the POST requesttopay, is any number other than the ones from the list of test numbers on MTN Documentation https://momodeveloper.mtn.com/api-documentation/testing/ , then the response returned will ALWAYS be SUCCESSFUL If you want to see a response with Status: PENDING or FAILED, then you need to use a test number from MTN's MoMo Documentation Website: https://momodeveloper.mtn.com/api-documentation/testing/ You are expected to have, at least, one Product Subscription before attempting to provision an API User Once you provision an API User in the Sandbox and the API Key, the two can then be used to create a Bearer Token Access Token The Bearer Token can then be used to make api calls for any of the Product Subscriptions. It will be sent as part of the Authorization Header of every api call. Note that each Bearer Token issued has an expiry, usually 3600 seconds The value for Ocp-Apim-Subscription-Key header will ALWAYS be the SAME for ALL Endpoints in a given Product Subscription The value for X-Reference-Id header should ALWAYS be UNIQUE/DIFFERENT for each POST Request where the X-Reference-Id is expected to be in the header Whenever the X-Reference-Id is expected to be passed as a Request Parameter either in a POST or GET request , use an existing X-Reference-Id corresponding to the referenced resource Hint Steps 1 through 5 can be used as the typical flow for implementing a MoMo Payment Integration for your payment solution After testing the steps in Postman, copy each step logic/flow and write the corresponding code in your preferred language .