OpenSea has partnered with NFT analysis tool Curio, NFT analysis platform icy.tools, and Moonbirds parent company PROOF to develop the open standard OpenRarity for NFT rarity, which will be launched on OpenSea next week. OpenSea said that the current rarity rankings on the market are generated by closed source code, which is prone to disagreement, and tool providers often charge for rarity rankings, which cannot provide a level playing field for smaller budget projects. OpenRarity aims to provide a transparent, mathematically sound open-source rarity calculation, improving the transparency of NFT rarity rankings. Developers can access OpenRarity scores and rankings through an API.