Amazon Marketplace Web Service (MWS) will no longer be available after March 31, 2024. All MWS developers must migrate to Selling Partner API (SP-API) to avoid service disruptions. Refer to the Migration Hub for more information.
To build a web application for Amazon sellers, you must first register as a developer. See Registering as a developer. On the last page of the registration workflow, make note of your Developer ID, as you will need to provide this to sellers who want to use your developer services or web application. You can get your Developer ID at any time by going to the User Permissions page on Seller Central. For more information, see Where do I find my identifiers and credentials?.
When your web application is ready, provide sellers with your Developer ID, which they can use to authorize you for developer access to their selling accounts. A seller authorizes you as a developer from the User Permissions page in Seller Central. For more information, see I am a developer and I want to develop Amazon MWS applications for sellers. What should I do?.
The seller provides you with the MWS Auth Token associated with your developer account and their Seller ID. You can then make Amazon MWS requests on their behalf, using the seller's identifiers and your developer credentials.
For further assistance with building Amazon MWS applications, see Related Resources.