# Stackable DeFi Primitives #### “Structured Finance” is the process of abstraction: utilizing layers of liquidity mechanisms to achieve full risk transfer, like thermal dynamics but for finance, only achievable on-chain through stackable, composable DeFi primitives. USD.AI and the corresponding token representations (USDai and sUSDai) represent the latest progression of the legacy MetaStreet architecture & ecosystem around on-chain structured credit products. Given the nature of capital market assets (low mark-to-market), USD.AI rebuilds the entire DeFi stack to be oracleless & made for capital assets rather than just money assets (spot market & oracle-based) designed around three pillars: 1. [CALIBER](https://docs.usd.ai/solution-overview/1.-caliber-yield) — a framework for tokenization or Yield. Creating the ability to tokenize previously un-tokenizable assets 2. [FiLo](https://docs.usd.ai/solution-overview/2.-filo-curator-scale) — a process for risk curation or Scale. Allowing future asset financing demand to be vetted and publicly funded 3. [QEV](https://docs.usd.ai/3.-qev-redeem) — a system for liquidity or Redemption. Allowing fair and transparent access to liquidity Below is a detailed timeline and evolution of these stackable DeFi Primitives: ### Lending Without Price Oracles → [CALIBER](https://docs.usd.ai/solution-overview/1.-caliber-yield) * **Automatic Tranche Maker or "ATM"** (like Uniswap v3 for oracleless swaps) enables oracleless lending for low-liquidity assets (NFTs, RWAs, etc) * Launched in 2023, reached $3mm TVL ### Long-dated, Yield-Bearing Loans → [QEV](https://docs.usd.ai/3.-qev-redeem) * **Liquid Credit Token or "LCT"** (similar to Lido) enables trading of yield-bearing tranche positions, “rebases” upon loan repayments * Launched in 2024, reached $60mm TVL ### Modular Underwriting (RWA Asset Origination) → [CALIBER](https://docs.usd.ai/solution-overview/1.-caliber-yield) & [FiLo](https://docs.usd.ai/solution-overview/2.-filo-curator-scale) * **ObjectSDK** (comparable to Morpho Blue for DePIN/RWAs) enables modular underwriting system for low latency appraisals & amortization schedules * Launched in 2024, enabled 20 new assets ### Yield Splitting Without Spot LP → [CALIBER](https://docs.usd.ai/solution-overview/1.-caliber-yield) * **Yield Pass** (similar to Pendle but for NFTs) strips & isolates yields but for productive illiquid assets, such as Node Licenses * Launched in 2024, reached $202mm TVL ### USD.AI Synthetic Dollar for Unified Liquidity Layer ([CALIBER](https://docs.usd.ai/solution-overview/1.-caliber-yield) & [FiLo](https://docs.usd.ai/solution-overview/2.-filo-curator-scale)) * USD.AI (**like “GLP/HLP”** - a single token for multiple collateral types) is a yield-bearing synthetic dollar backed by loans against AI hardware (InfraFi) * Targeting 10-15% APR, but initially starting as a T-Bill yield-bearing product with plans to progressively diversify collateral base to InfraFi assets * Launched in 2025, current TVL can be viewed at ### Queue Extractable Value ([QEV](https://docs.usd.ai/3.-qev-redeem)) to Optimize Redemption Liquidity * QEV-Boost – a liquidity incentive system based on epoch timing (**similar to Flashbots**) that improves USD.AI liquidity allocation through **market-driven queue ordering** * Structured redemption queue based on payment schedules * Stakers can bid in QEV auctions for priority access to liquidity * Fair distribution through proportional queue advancement * Passive stakers earn rewards from smoothed yields and auction fees * Target: Enhance redemption efficiency to earn **up to 3% of protocol yield** via QEV prioritization {% hint style="info" %} For those who are curious on how the structure was created at the smart contract level please see the original documentation: docs.metastreet.xyz MetaStreet protocol was designed through the theory of Object Oriented Finance. Nansen report is here: {% endhint %}