> ## Documentation Index > Fetch the complete documentation index at: https://docs.kimia.live/llms.txt > Use this file to discover all available pages before exploring further. # Architecture > How six Anchor programs compose into one fixed-income stack. Kimia is not a monolith. Every responsibility, matching engine, hedging, tokenization, AMM, stablecoin, is a separate Anchor program, and the programs talk to each other via CPI. This makes each piece usable in isolation. ## Program map Matching engine, orderbook, funding, liquidation, spot pool. Holds USDC, opens/maintains a SOL-PERP short, mints vault shares. Wraps vault shares into `PT` + `YT` with MasterChef-style yield accounting. Yield-space AMM for PT ↔ underlying, with prices that decay into par at maturity. Session state machine that verifies a multi-step fixed-rate lock succeeded. Stablecoin with multi-reserve backing and staking-based yield distribution. ## Layered view Architecture diagram: frontend and Next.js, intent router with session state machine, protocol layer with split-engine, yield-amm, and kusd-mint, delta vault, Kimia perp, and Pyth Hermes pull oracles for price feeds.

Architecture diagram: frontend and Next.js, intent router with session state machine, protocol layer with split-engine, yield-amm, and kusd-mint, delta vault, Kimia perp, and Pyth Hermes pull oracles for price feeds.

## CPI graph Arrows mean "A invokes B via CPI" between Kimia's own programs. External programs can CPI in the same way, but note that Kimia does not publish its program crates to crates.io — consumers add them as `path` or `git` dependencies in their own `Cargo.toml` with `features = ["cpi"]`. Diagram: user opens a multi-tx session with intent-router; the router verifies by reading account state; delta-vault CPIs into kimia-perp for deposit_collateral, spot_swap, place_order, and settle_funding; split-engine reads vault share price from kimia-perp; yield-amm uses kimia-math and vault shares.

Diagram: user opens a multi-tx session with intent-router; the router verifies by reading account state; delta-vault CPIs into kimia-perp for deposit_collateral, spot_swap, place_order, and settle_funding; split-engine reads vault share price from kimia-perp; yield-amm uses kimia-math and vault shares.

## The fixed-rate lock, three transactions The canonical user flow uses all five programs to turn USDC into a guaranteed fixed rate: User calls `delta-vault::deposit(amount, open_perp=true)`. The vault splits the deposit 50/50, swaps one half into wSOL via `spot_swap`, and opens a matching SOL-PERP short via `place_order`. The user receives **vault shares**. User calls `split-engine::deposit(vault_shares)`. The engine escrows the vault shares and mints PT (1:1) and YT (1:1) to the user. User calls `yield-amm::swap(YT → underlying)`. YT trades at a discount, the difference between what you paid and what you got back is the prepaid yield. The intent-router recomputes the achieved APY from the swap receipts and reverts if it's below the user's `target_rate`. This is what makes it a "fixed-rate intent" instead of a hopeful multi-step script. ## Design principles Matching ≠ hedging ≠ tokenizing. Each program's account model is independently auditable, and integrations only need to grok the parts they use. `update_funding_rate`, `liquidate`, `update_rewards`, and `rebalance` can be called by anyone. The protocol pays the liquidator and skims yield for the insurance fund, incentives align, no whitelist. Open orders lock collateral at placement. You can't over-leverage by spamming the orderbook, a position and a resting order compete for the same free collateral. The shared `kimia-math` and `perps-math` crates always round down on the user's side. No "\$0.00000001 of free money" arbitrage.