StETHRedeemManager

Title: StETHRedeemManager

Abstract contract implementing EIP-7540 Asynchronous ERC-4626 Tokenized Vaults. LP shares are burned immediately on requestRedeem; WETH is delivered asynchronously in FIFO order as Lido withdrawal claims arrive. Supports partial fulfillment: a request can receive a portion of its WETH now and the remainder from future Lido claims.

Actors:

• owner - whose shares are burned on requestRedeem.
• controller - controls when and to whom assets are claimed.
• operator - approved by owner/controller to act on their behalf.

Flow:

1. Owner (or operator for owner) calls requestRedeem(shares, controller, owner). Shares burned immediately; a request record is created for controller.
2. As ETH arrives from Lido claims, _serveRedeemRequests allocates WETH to the oldest pending requests first (FIFO). Partial allocation is supported: _redeemHead advances only when a request is fully allocated.
3. Controller (or operator for controller) calls claimRedeem(receiver, controller) which transfers all currently claimable WETH for that controller to receiver.

Accounting invariants:

• _pendingRedeemAssets = sum of (assets - claimableAssets) for all requests. Subtracted from totalAssets() so remaining LPs see the correct share price.
• _reservedRedeemAssets = sum of (claimableAssets - claimedAssets) for all requests. Excluded from swap liquidity and from totalAssets().

Functions

setOperator

Grant or revoke operator privileges for msg.sender as controller. Operators can call requestRedeem and claimRedeem on behalf of the controller.

function setOperator(address operator, bool approved) external returns (bool);

Returns

Name	Type	Description
<none>	bool	Always true (EIP-7540 compliance).

isOperator

Returns whether operator is approved to act on behalf of controller.

function isOperator(address controller, address operator) public view returns (bool);

requestRedeem

Burn shares from owner and register an async redemption request. The WETH payout is delivered asynchronously (FIFO) as Lido withdrawal claims arrive. Caller must be owner or an approved operator for owner.

function requestRedeem(uint256 shares, address controller, address owner)
    public
    virtual
    returns (uint256 requestId);

Parameters

Name	Type	Description
shares	uint256	Vault shares to redeem.
controller	address	Address that will control when/to whom assets are claimed.
owner	address	Address whose shares are burned.

Returns

Name	Type	Description
requestId	uint256	Global ID for this request (use with claimRedeem).

claimRedeem

Transfer all currently claimable WETH for controller to receiver. Caller must be controller or an approved operator for controller.

function claimRedeem(address receiver, address controller) public virtual returns (uint256 totalClaimed);

Parameters

Name	Type	Description
receiver	address	Address to receive the WETH.
controller	address	The controller whose claimable assets are claimed.

Returns

Name	Type	Description
totalClaimed	uint256	Total WETH transferred (0 if nothing is currently claimable).

redeemRequestIds

Returns all request IDs controlled by controller (including fully claimed ones).

function redeemRequestIds(address controller) external view returns (uint256[] memory);

redeemRequest

Returns the full status of a single request.

function redeemRequest(uint256 requestId)
    external
    view
    returns (uint256 assets, address controller, uint256 claimableAssets, uint256 claimedAssets);

redeemQueueLength

Total number of requests ever created (includes fully claimed ones).

function redeemQueueLength() external view returns (uint256);

reservedRedeemAssets

WETH currently reserved for allocated (but not yet claimed) redeem requests. This WETH is excluded from swap liquidity.

function reservedRedeemAssets() external view returns (uint256);

pendingRedeemRequest

EIP-7540: assets still pending allocation for a specific request. Returns 0 if controller does not match the request's controller.

function pendingRedeemRequest(uint256 requestId, address controller) external view returns (uint256);

claimableRedeemRequest

EIP-7540: assets claimable but not yet claimed for a specific request. Returns 0 if controller does not match the request's controller.

function claimableRedeemRequest(uint256 requestId, address controller) external view returns (uint256);

Events

OperatorSet

Emitted when a controller grants or revokes operator status (EIP-7540).

event OperatorSet(address indexed controller, address indexed operator, bool approved);

RedeemRequested

Emitted when an LP submits a redemption request.

event RedeemRequested(
    uint256 indexed requestId,
    address indexed controller,
    address indexed owner,
    uint256 shares,
    uint256 assets
);

Parameters

Name	Type	Description
requestId	uint256	Global ID assigned to this request.
controller	address	Address that controls claiming for this request.
owner	address	Address whose shares were burned.
shares	uint256	Vault shares burned.
assets	uint256	WETH amount promised.

RedeemClaimed

Emitted when claimable WETH is transferred to a receiver.

event RedeemClaimed(address indexed receiver, address indexed controller, uint256 assets);

Parameters

Name	Type	Description
receiver	address	Address that received the WETH.
controller	address	Controller whose claimable assets were claimed.
assets	uint256	Amount of WETH transferred.

Errors

NotAuthorized

error NotAuthorized();

MinSharesRequired

error MinSharesRequired(uint256 shares, uint256 minimum);

InsufficientClaimable

error InsufficientClaimable();

Structs

RedeemRequest

One entry per redemption request.

struct RedeemRequest {
    uint256 assets;          // total WETH owed (fixed at requestRedeem time)
    address controller;      // address that controls when/to whom assets are claimed
    uint256 claimableAssets; // WETH allocated so far (may be partial)
    uint256 claimedAssets;   // WETH already transferred to a receiver
}