Not an NFT. Not a token in the conventional sense. jPEG uses Uniswap v4 hooks to render unique 24×24 collectible images entirely on-chain. No external storage. No IPFS.
When v4 shipped, I noticed one detail that stood out: hooks. Custom logic that runs directly at the point of exchange, not wrapped around it or bolted on top. That's a small technical change with a large design space behind it. jPEG is an attempt to show what that actually means.
Each image is tied to a specific integer amount of jPEG — 1, 2, 3 and so on. When a swap occurs, the hook generates a hash encoding layers, colors, and the original owner. That hash is the input. The SVG renderer reads it and assembles a unique creature.
The object's appearance is a function of market activity. Every trade that touches the pool produces a new number. That number is what gets rendered.
A custom Uniswap v4 hook that intercepts swaps and generates deterministic hashes based on pool state, trading volume, and caller address.
On-chain SVG assembly. No off-chain computation. The hash is decoded into layers, colors, and traits — all rendered in solidity.
The appearance emerges from market activity. Not minted by clicking a button — minted by trading. Every swap is a birth event.
NFTs were always called JPEGs. Uniswap was almost called Unipeg.
A peg being a rule enforced at the point of exchange.