vlSDT: Vote Locked SDT

vlSDT is Stake DAO's new staking system that replaces the decaying vote-escrow model with flat voting power and flexible exit through an unstake queue.

Overview

vlSDT simplifies SDT staking while maintaining the core utility of veSDT:

• Flat voting power: 1 staked SDT = 1 vlSDT voting power (no decay)
• No lock duration: Stake and unstake anytime
• 8-week exit queue: Request unstake, receive SDT after 8 weeks
• Cancellable: Pending unstake requests can be cancelled to restore voting power
• Protocol fees: Earn your share of protocol revenue through epoch-based distribution

Architecture

vlSDT vs veSDT

Voting Power

Your vlSDT voting power is calculated as:

Unlike veSDT where voting power decays over time, vlSDT provides constant 1:1 voting power. When you stake 100 SDT, you get 100 vlSDT voting power until you request unstake.

Staking

To stake SDT and receive vlSDT voting power:

1. Approve the vlSDT contract to spend your SDT
2. Stake your SDT (you can stake for yourself or another address)
3. Voting power is credited immediately
4. A checkpoint is recorded for fee distribution eligibility

See the Stake vlSDT Guide for step-by-step instructions.

Unstaking

vlSDT uses an 8-week unstake queue instead of lock expiry:

1. Request unstake: Call unstake with the amount you want to withdraw
2. Voting power reduced: Your vlSDT is burned immediately
3. Wait period: SDT enters an 8-week withdrawal queue
4. Complete withdrawal: After 8 weeks, withdraw your SDT

Cancelling Unstake

Changed your mind? Pending unstake requests can be cancelled at any time before the 8-week period ends:

• Your voting power is restored immediately
• The unstake request is deleted
• You continue earning fee rewards

Fee Distribution

vlSDT holders earn a share of protocol fees distributed through the FeeDistributor contract.

How It Works

• Epoch duration: 7 days (aligned with gauge epochs)
• Epoch boundary: Thursday 00:00 UTC
• Eligibility: Based on your balance at the start of each epoch

Reward Calculation

Important Notes

• You earn rewards starting from the first full epoch after staking
• Claims can be made at any time for all accumulated epochs
• Anyone can trigger a claim on your behalf (rewards always go to you)

Operational Details

• Checkpoint frequency: checkpointToken() processes a maximum of 20 epochs per call. If many epochs have passed without a checkpoint, it may need to be called multiple times.
• Claim limits: claim() processes a maximum of 50 epochs per call. Users who haven't claimed for a long time may need to call claim() multiple times to collect all rewards.
• Auto-checkpoint: If more than 1 day has passed since the last token checkpoint, any claim() call will automatically trigger a checkpoint first, ensuring newly deposited tokens are distributed.
• Zero supply epochs: Tokens allocated to epochs where no one is staked are permanently unrecoverable. While deposit() requires at least one staker, edge cases remain if all users unstake after a deposit but before the epoch ends.

Migration from veSDT

Existing veSDT holders can migrate to vlSDT at any time. Migration:

• Transfers your full locked SDT amount (ignoring decay)
• Works for both active locks and expired locks
• Is a one-way process (cannot migrate back to veSDT)
• Is not blocked by old veBoost delegations. Note that boost from the old veBoost system no longer applies on sdToken vaults — only vlSDT and the new BoostMarketplace count. If you bought boost in the past, it's no longer credited to you; if you sold boost, it's no longer costing you anything.

See the Migration Guide for detailed instructions.

Boost and Delegations

vlSDT boost replaces veSDT's decaying delegation system with flat, non-decaying delegations.

BoostRegistry

The BoostRegistry enables flat boost delegations with week-aligned expiry timestamps.

• Choose an amount and expiry (must be a Thursday 00:00 UTC boundary, max 52 weeks out)
• The delegation stays at its full amount until expiry, then drops to zero
• Your delegable balance is your voting power minus active outgoing delegations
• Your adjusted balance (for strategies) is voting power - delegated out + delegated in

• You can approve other addresses (such as the BoostMarketplace) to create delegations on your behalf
• Call setOperator(address, true) to approve an operator
• Operators can only delegate your existing balance, not exceed it

See the developer integration page for technical details and code examples.

BoostMarketplace

The BoostMarketplace is an on-chain order book for buying and selling boost delegations.

• Create a listing with price per week, max duration, and payment token
• Buyers fill your listing and receive delegated boost automatically
• Your listing capacity is reserved (committed) until filled or cancelled
• Update or cancel listings at any time

• Create an offer by escrowing funds in the marketplace
• Sellers accept your offer and boost is delegated to you
• If your offer isn't filled, cancel it to reclaim escrowed funds
• Update or cancel offers at any time

• Buyers set maxTotalPayment when filling listings (slippage protection)
• Sellers set minTotalPayment when accepting offers (slippage protection)

• A configurable fee (in basis points) is deducted from trades, set by governance

See the developer integration page for API details, struct definitions, and code examples.

Coexistence with veSDT

Both systems still exist side by side, but they play different roles:

• veSDT: existing locks keep working for withdrawals at expiry and for Snapshot voting, but veSDT balances no longer give any boost on sdToken vaults.
• vlSDT: the only source of sdToken boost going forward, with flat 1:1 voting power.
• Migration is optional, not time-limited — but if you want to keep earning boosted rewards on sdToken vaults, you need to migrate.

Contract Addresses

See the Contract Addresses page for vlSDT contract addresses.

Related Documentation

• Stake vlSDT Guide
• Migration Guide
• Developer Integration
• veSDT (Sunset)
• SDT Token
• Governance