A primer on the mental models

Five ideas make the rest of Atlas click. If your intuition comes from a single-chain world, these are the places it needs to bend. Read what Citrate is first if you have not.

What it is

A short tour of the concepts the deeper pages assume. Each one ends with a pointer to where it is treated in full.

Blue score, not height

On a single-parent chain, "block N" is unambiguous. On a BlockDAG, a block can name several parents, so height alone cannot order the ledger.

• Height is roughly how many layers deep a block sits. It is useful, but it is not the ordering key.
• Blue score is the ordering key GhostDAG uses: the cumulative count of a block's blue ancestors, the honest-majority-consistent set picked out by the k-cluster rule (k = 18). The tip with the highest blue score wins.

Blue score is the DAG's clock. When you read citrate_getDagStats, the field that tells you the head is maxBlueScore, not height. Full detail under Citrate Network.

Finality by depth

Citrate finalizes by depth, not by a single special block. A block is final once it sits 100 blocks (finality_depth) behind the selected tip, and any reorg that would rewrite a finalized block is rejected when the block is admitted. There is a BFT checkpoint mechanism layered on top, but depth is the everyday rule: the deeper a block, the more final it is, and past depth 100 it cannot be reorged. See finality.

Merge parents

A block names one selected parent, the place on the chain it builds on, plus zero or more merge parents, other tips it folds into the order. Merging is how the DAG stays one ledger instead of forking: a block absorbs its sibling tips rather than orphaning them. Selected parent is where you stand; merge parents are the siblings you are folding in. The block's mergeset is then interleaved into the canonical order. See Citrate Network.

Accounts without a seed phrase

Citrate accounts live in Citrate Keyring. An account is a smart contract, and you sign in with a passkey (WebAuthn over P-256) or an existing key, so there is no seed phrase to lose. Transactions are sent as user operations through a bundler, and a sponsor contract can pay the fee, so you can transact with no SALT in hand. Recovery is by guardians, two to seven of a set you choose, and Citrate is never one of your guardians. The account is a contract, the key is a passkey, and someone else can cover the fee. See Citrate Keyring, sponsorship, and guardians.

SALT, the unit you count in

SALT has 18 decimals and a one-billion supply cap, and it settles fees, block rewards, and staking. Amounts in the API are integers in the smallest unit, where 10^18 is one SALT, and supply is minted minus burned, held under the cap. SALT measures the work the network does; it is not a product to hold. See economics.

How to use it

Put the five together and a transaction's life reads cleanly. You sign a user operation with a passkey, a bundler submits it, the execution layer runs it (often alongside others, in parallel), and it lands in a block that names a selected parent and maybe some merge parents. GhostDAG assigns the block a blue score and places it in the total order. Once the block is 100 deep, it is final. The fee and any reward are denominated in SALT. If you can hold that sentence in your head, the rest of Atlas will read easily.

Reference

Idea	The key fact	Where it is treated in full
Blue score	ordering key; maxBlueScore is the head	consensus
Finality	final at depth 100, no reorg past it	consensus, finality
Merge parents	one selected parent, many merge parents	consensus
Citrate Keyring	smart-contract account, passkey, sponsored fees	Citrate Keyring
SALT	18 decimals, 1B cap, settles work	economics

Access and canon

Public. These are conceptual explainers only, with no secrets, keys, or private endpoints. The proofs behind GhostDAG and finality are academic-tier and live on the linked Citrate Network pages.

Source and verification

The numbers (k = 18, finality depth 100, SALT 18 decimals and 1B cap, chain id 40204) are verified against citrate-chain at 03d7851: core/consensus/src/types.rs and core/api/src/economics_rpc.rs, surfaced through the consensus and economics pages. Status: Implemented (testnet).