How to use NFT.Kred APIs?

Use the NFT.Kred API to build your own custom application or front end website.



The API offers two extension mechanisms:

Webhooks which are available for both developers building their own applications, and to end users of applications

Functions which are available only to developers.


Webhooks operate asynchronously. Any applicable webhooks are called after the API call is executed, and if the respective webhook service is down or not responding, are queued to be retried periodically until successful. A webhook service must respond with a 200 or 202 status code to confirm receipt.

Functions operate synchronously with the API, and may be inserted before or after the API call executes, or both. Pre-execution methods can return an error status (and HTTP status code of 400 or greater), in which case the API call itself will be aborted, and the function status returned to the API client. Post-execution function errors cannot in general roll back the API execution, as the blockchain may have been updated already. Instead, in case of a post-execution function returning an error, the API call will return a status of 207 instead of 200, and the details of the function response will be included.

Users of these features fall into three main groups: NFT owners, NFT creators, and application developers.

NFT owners can trigger notifications via webhook when any of the following events takes place on a NFT they currently own (for transfers, that they own before or after the transfer).

  • Sales
  • Purchases
  • Auction bids
  • Auction expiry
  • Likes
  • Comments
  • Replies
  • Showcase
  • Market listings
  • Requests
  • Claims
  • Gifts

NFT creators can trigger notifications on NFTs even after they are transferred (sold or given away), and continue to receive notifications for as long as the NFT remains in active circulation. Creators receive notifications for:

  • Transfers
  • New members (transfers to a user who has not held the NFT previously)
  • Likes
  • Comments
  • Replies
  • Bans
  • Metadata updates

Developers have the widest range of notifications available. As a developer you can add webhook notifications to all API methods that create or modify data, and add functions to all methods called by your users.

When your users perform actions that require you to initiate a blockchain transaction, a prebuilt transaction will be sent to your defined endpoint for you to verify, sign, and send.

Webhooks and functions can be implemented on any server (or serverless) architecture, and in any language, as long as it supports HTTPS and JSON. For functions performance is a consideration, and it is recommended that your services be located relatively close to the API servers (in terms of ping time) to avoid delaying API calls.