GooseFX Whitepaper
NFT Appraisal API Documentation
If you have any additional examples or added documentation that we could add please reach out to a team member in discord! We would love to include it.

For the past six months, we have been building what we believe to be one of the world's most accurate appraisal engines for non-fungible tokens. By combining mathematical modeling and machine learning, we have built an NFT appraisal tool with an R2 score of 0.92. We are currently packaging the model into a service we are calling the β€œGFX NFT Appraisal Engine”, which will be available from a web interface and through an API at

  • GFX Specific Rarity Appraisal - a unique appraisal value taking into account attributes and rarity of a specified NFT
  • GFX Collection Appraisal - a new appraisal value applying to any generic NFT in a collection. This is intended to replace the collection floor price metric as a much more appropriate data point.
  • Collection Mint ID List - Returns the complete collections mint ID list
  • GFX Appraisal Supported Collections List - Returns a complete list of Appraisal Engine-supported collections.
Let's look at the examples below for more details.

To get a real-time valuation (in SOL) of any NFT belonging to one of these collections, get a token_id, for instance, AVrGwmwkQkoaCBx3UcAhDHca9hJReEtjaG797UY5yHtp for SMB #664, and then call the API with the ID, like so:
To get a response in the following format.
This amount of 248.63 represents the Specific Rarity Appraisal of the #664, SMB NFT in Solana.

We have also developed a collection level appraisal metric that tracks the bottom quantile of NFT sales over time. This results in a metric that resembles some characteristics of the commonly used β€œfloor price”, but with less volatile fluctuations and fewer possible attack vectors for price manipulation, meaning that our appraisal engine is well suited to build products around.
The Collection Appraisal call takes in the collection name to return the value. replace the Collection name from the example call below and viola!
For instance, to get the Collection Appraisal of the Solana Monkey Business collection, call the API like this:
And you get the response: {"Solana_Monkey_Business":234.94823853138848}
This amount of 234.94.. represents the GFX Collection Appraisal for the SMB collection.

Much like above, just swap out the collection names and use the "+" for spaces to utilize this call.
Collection Mint ID List
Currently Supported Collections for GFX Appraisal Engine
Currently, the Appraisal Engine Supports these collections:
  • Solana Monkey Business = "Solana+Monkey+Business"
  • Thugbirdz = "Thugbirdz"
  • Pesky Penguins = "Pesky+Penguins"
  • Degen Ape Academy = "Degenerate+Ape+Academy"
  • Degods = "Degods"
  • Doge Capital = "Doge+Capital"
  • Famous Fox Federation = "Famous+Fox+Federation"
  • Stoned Ape Crew = "Stoned+Ape+Crew"
  • Aurory = "Aurory"
  • Blocksmith Labs = "Blocksmith+Labs"
  • Catalina Whale Mixer = "Catalina+Whales"
  • Cets on Creck = "Cets+On+Creck"

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Background - NFT Appraisal As a Service
Usage Examples