Lets creators build mystery packs with cryptographically fair odds and instant physical fulfillment.
Using provable fairness optimization for pack odds, computer vision card image authentication, and recommendation engines with dynamic marketplace pricing.

|
Consumer Marketplace
|
YC W26

Last Updated:
March 19, 2026

iOS and web platform that lets creators build custom mystery packs with personalized odds, cryptographically trusted tooling, and a $1 marketplace for digital pack openings with optional physical card fulfillment and instant payouts via Venmo and PayPal.
Custom mystery pack creation with personalized chase odds, digital pack openings with animations, $1 marketplace, instant buyout offers with Venmo/PayPal payouts. Partnership with Nexus Labs for blockchain-backed transparency.
iOS-first with web secondary. No Android app yet. Nexus mainnet integration hints at on-chain verification and possible NFT features. Community demand for more card types beyond Pokemon and sports.
<p>A machine-learning model dynamically assembles mystery packs by optimizing card allocation against creator-defined odds while a cryptographic commitment scheme lets buyers independently verify that every pull was fair.</p>
It's like a slot machine that publishes its own math homework so you can check it never cheated.
CatchBack Cards pairs a constrained optimization model with a cryptographic commitment protocol anchored on the Nexus mainnet. When a creator sets chase odds (e.g., 1-in-50 for a rare insert), the ML layer solves a bin-packing-style allocation problem across available inventory, balancing rarity targets, pack price points, and remaining stock levels in real time. Before any pack is opened, a hash of the pack contents is committed on-chain; after the reveal, the buyer can verify the pre-image against the hash, proving the outcome was determined before purchase. The model continuously recalibrates as inventory depletes, ensuring advertised odds hold across the full print run rather than just on average—addressing a persistent trust gap in the hobby where breakers have historically been accused of cherry-picking hits. This closes the loop between marketplace liquidity (buyers trust the product) and creator retention (creators see higher sell-through rates).
It's like a magician doing a card trick, except the audience gets to watch the security-camera footage afterward and confirm nothing was up the sleeve.
<p>A computer-vision pipeline analyzes user-uploaded card photos to authenticate cards against a reference database and assign a preliminary condition grade, reducing fraud and enabling confident instant buyout pricing.</p>
Your phone's camera becomes a tiny card-grading expert that spots fakes and surface scratches before money changes hands.
When a seller lists a card or a buyer receives a physical card from a pack, the platform prompts a multi-angle photo upload. A fine-tuned convolutional neural network (EfficientNet backbone) first performs authentication by comparing extracted visual embeddings against a canonical reference set of known printings, flagging reprints, proxies, and counterfeits with a confidence score. A second model head, trained on labeled datasets of PSA/BGS-graded cards, predicts a preliminary condition tier (e.g., Near Mint, Lightly Played) by detecting centering offsets, corner whitening, surface scratches, and edge wear at sub-millimeter resolution. The combined output feeds directly into the instant-buyout pricing engine: authenticated cards in higher condition tiers receive higher offers, while flagged cards are routed to manual review. This creates a trust layer that is critical for a marketplace where buyers never physically inspect cards before purchasing, and it lets CatchBack Cards offer competitive buyout prices with controlled risk exposure.
It's like having a jeweler with a loupe inspect every card at the speed of a barcode scanner.
<p>A recommendation engine analyzes buyer behavior, market comps, and creator inventory to surface the highest-affinity packs per user while a dynamic pricing model adjusts pack prices in real time to maximize sell-through and creator revenue.</p>
The app figures out which mystery packs you'll love most and prices them just right so creators sell out and buyers feel like they got a deal.
The system ingests three signal streams: (1) user interaction data (views, wishlist adds, purchases, pack-opening watch time), (2) external market comps from eBay sold listings and price guide APIs for the underlying cards, and (3) creator inventory metadata (card set, era, sport/brand, stated chase value). A collaborative-filtering model (matrix factorization augmented with content-based features via a two-tower neural retrieval architecture) generates ranked pack recommendations for each buyer session, surfacing creators and card categories the buyer is statistically most likely to purchase. Simultaneously, a contextual bandit adjusts pack prices within creator-defined bounds based on real-time demand velocity, remaining inventory, time since drop, and comparable pack sell-through curves. When demand spikes, prices nudge upward to capture surplus; when packs stall, the model applies micro-discounts or bundles complementary packs to restart momentum. The feedback loop is tight: every purchase or skip updates both models, and creators receive a dashboard showing recommended price adjustments and audience insights, turning the platform into a data-driven sales partner rather than a passive listing tool.
It's like a flea-market vendor who somehow already knows you collect '90s basketball rookies and adjusts the sticker price right as you walk up to the table.
Combines cryptographically trusted odds with instant physical-card fulfillment and frictionless payouts, creating a trust-and-liquidity moat that pure digital or pure physical competitors lack.