Products
Yield Marketplace. Sundial’s user-facing product: a marketplace where depositors choose among Yield Providers. The depositor picks a provider and never picks the rail behind it. Yield Provider. A party whose yield strategy is listed on the Yield Marketplace. A provider that already has an on-chain presence can list directly. One that doesn’t runs on a Sundial rail, which the provider chooses. Rail. A ready-made on-chain structure that a Yield Provider integrates with. Dawn and Solstice are rails. Dawn. The segregated rail. Each deposit is its own timelocked BTC escrow that earns a fixed rate from the provider behind it. Solstice. The pooled rail. Each provider has one vault that issues its own receipt token, redeemable at the vault’s Claim Ratio. Solstice is a peer of Dawn, not a successor to it. Claim Ratio. In Solstice, the amount of BTC that one receipt token redeems for. It rises as the vault’s BTC earns. Alchemy. A product in its own right, not a rail: one BTC reserve that issues two claims against it, FIRE and ICE. Built on Sunbeam. FIRE. Alchemy’s junior claim. It absorbs the reserve’s downside first and takes the residual upside. ICE. Alchemy’s senior claim: a lower-volatility, USD-denominated claim on the same reserve. It is not a short-Bitcoin position and not a stablecoin. Sunbeam. Sundial’s beaming product. It moves Bitcoin-native assets from Bitcoin to a destination chain, built on Charms. Charms. The open-source protocol that Sunbeam builds on: programmable assets attached to Bitcoin UTXOs, each transaction carrying a proof that its app contract was satisfied. Beaming. A cross-chain transfer in Charms: an asset is destroyed on the source chain and re-created on the destination chain, tied together by a hash commitment and a finality proof. btc-locker. The TypeScript library of Bitcoin scripts, timelocks and PSBT builders that Dawn and Solstice are built on. It is a library, not a product.Sundial L2
Sundial L2. Sundial’s optimistic rollup, built on the Midgard design by Anastasia Labs and settling to Cardano. Midgard. The optimistic rollup design that the Sundial L2 is built on. Package names such asmidgard-node and midgard-sdk come from it.
Operator. A party that receives L2 transactions, assembles blocks, publishes them and commits their headers during its shift.
Active operator. An operator in the active set, taking part in the rotating schedule.
Bond. The collateral an operator posts to back its promise to commit valid blocks. A block proven fraudulent forfeits it.
Watcher. Any party that reads committed blocks from the data availability layer and submits fraud proofs.
Fraud prover. The watcher that starts a computation thread and receives the reward when the proof removes a block.
Fraud proof. A demonstration, verified on the L1 by a computation thread, that a block violates a ledger rule.
Computation thread. A chain of spending validators, each one a step, that verifies a fraud proof in pieces small enough for L1 transaction limits.
State queue. The L1 linked list that holds committed block headers until they are merged or disqualified.
Confirmed state. The record at the root of the state queue: the last confirmed header’s hash, its UTXO root, its time bounds and its protocol version.
Maturity period. The time a committed header waits in the state queue before it can be merged.
Shift. An interval in which one operator has the exclusive right to commit blocks.
Scheduler. The L1 UTXO that names the operator of the current shift.
Operator directory. The three L1 lists of registered, active and retired operators.
Event interval. The half-open time interval that a block claims. A block must include every L1 user event whose inclusion time falls inside it.
Inclusion time. The time at which an L1 event must be included in a block: the upper bound of the creating transaction’s validity interval plus a fixed wait.
Deposit. An L1 event that moves a UTXO’s tokens to the L2 ledger.
Withdrawal order. An L1 event that orders the transfer of an L2 UTXO’s value to L1.
Transaction order. An L1 event that obliges operators to include a given L2 transaction.
Settlement queue. The set of settlement UTXOs, one per merged block with user events, that let users absorb deposits and pay out withdrawals.
Reserve. The L1 store of the funds of absorbed deposits.
Payout accumulator. An L1 UTXO that collects funds from the reserve until it can pay a confirmed withdrawal in full.
Escape hatch. The L1 mechanism that, when block production has stopped, opens an emergency period in which new operators can register with a reduced bond.
Archive node. A node that stores the block data of confirmed blocks.
Hub oracle. The L1 UTXO that stores the policy IDs and validator addresses of all Sundial L2 components.