> For the complete documentation index, see [llms.txt](https://docs.yodl.fi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yodl.fi/technical-components/smart-contracts.md).

# Smart Contracts

YODL’s on-chain architecture is modular and deterministic, ensuring transparent accounting for Operators and seamless integration with external vault systems such as Symbiotic.\
Each contract functions as a discrete, policy-enforced module within the execution, settlement, and restoration lifecycle.

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#### **Approver (with Registry & Policy)**

Acts as the central gatekeeper of the protocol.\
It binds the Curator Vault → Orchestrator → Operator relationship, enforces eligibility and top-up thresholds, and maintains allowlists for routers, oracles, and whitelisted taker tokens.\
All actions — quote execution, vault access, and policy enforcement — pass through the Approver to ensure compliance and risk isolation.

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#### **Orchestrator (per Execution Vault per Operator)**

Dedicated to each Vault–Operator pair, the Orchestrator manages execution and accounting.\
It holds pre-slashed vault inventory, validates RFQ + Permit2 witness signatures, records accounting transactions (`txn-s`), finalizes fees and converts taker proceeds into replenished vault inventory (`txn-f`), and enforces full epoch-end repayment.\
Because every Orchestrator is isolated, no cross-vault exposure exists — Operators never custody Curator capital, and all swaps occur atomically on-chain.

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#### **FeeManager (UUPS Upgradeable)**

Aggregates settlement data and routes fee-shares to Curators, Operators, and Delegators.\
It enforces fee-policy parameters (minimum Curator %, maximum gross %, venue-specific basis points), tracks fixed fee parameters, and allows all participants to claim their allocated fee-shares after settlement.

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#### **Delegation (Slashing & Restoration Utility)**

Handles slashing flows and deficit restoration during repayment or bounded liquidation.\
It converts slashed or held assets into the vault’s maker token via guarded, oracle-verified swaps, while maintaining cumulative deficit counters.\
This contract powers YODL’s bounded liquidation process and enforces full principal restoration for Curator vaults.

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#### **RewardsDistributor (Protocol Component)**

Routes surplus fee-shares allocated to Delegators for a given Operator.\
Upon notification from the FeeManager, it credits surplus allocations by operator and token, operating outside the fee-accounting path to keep the routing logic modular and auditable.

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#### **Execution Vault (External – Symbiotic)**

Represents the Curator’s single-asset vault allocated to an Operator.\
The vault’s base asset is the maker token that must be fully restored by the Operator each epoch.\
All interactions remain non-custodial and verifiable through YODL’s on-chain contracts, preserving solvency and neutrality at all times.

### <sup>YODL.sol — Token Contract</sup>

Implements the YODL ERC-20 token with a fixed supply cap, governance voting, and entity-based mint limits.\
Supports pausing, burning, and rescue of non-core tokens.

### Configuration Knobs

| Parameter         | Description                                                        | Changes Applicable    | Contract                       | Notes                                                         |
| ----------------- | ------------------------------------------------------------------ | --------------------- | ------------------------------ | ------------------------------------------------------------- |
| Fee Splits        | Operator defines fixed fee parameters for Curators and Delegators. | Next delegation epoch | FeeManager, RewardsDistributor | Must stay within DAO bounds; aggregator fee is independent.   |
| Surplus Share     | Operator sets surplus percentage allocated to Delegators.          | Next delegation epoch | RewardsDistributor             | Applies only if surplus is positive after deficit adjustment. |
| Accounting Inputs | Include quoted gross fee at each txn-s; must pass policy bounds.   | Per transaction       | Orchestrator, FeeManager       | Enforced fully on-chain.                                      |