Registry contract

Source: contracts/registry/src/lib.rs. Interface version 0. Testnet only.

Registered attestors post reserve reports per asset, a supply witness posts the asset’s supply, and anyone reads a status computed on read. Amounts are integers with 7 decimals. The contract never converts units: a report must state reserves in the unit the asset was registered with.

Constants

Name	Value	Meaning
BPS	10,000	Basis points in 100%
MAX_ATTESTORS	20	Attestors per asset
HISTORY_LEN	10	Reports kept per attestor per asset; older ones are dropped
DEFAULT_MAX_AGE_SECS	3,024,000 (35 days)	Suggested max_age_secs at registration
DEFAULT_MISMATCH_TOLERANCE_BPS	50 (0.5%)	Suggested tolerance at registration

Functions

Setup and roles

Function	Auth	Does
__constructor(admin: Address)	at deploy	Sets the contract admin
version() -> u32	none	0
admin() -> Address	none	The contract admin
register_asset(asset: Address, asset_admin: Address, unit: Symbol, max_age_secs: u64, mismatch_tolerance_bps: u32)	contract admin	Registers an asset (its token contract). Errors: AlreadyRegistered, InvalidPolicy
add_attestor(asset, attestor)	asset admin	Adds an attestor. Errors: NotRegistered, AlreadyAttestor, TooManyAttestors
remove_attestor(asset, attestor)	asset admin	Removes an attestor; its reports stay readable but stop counting. Errors: NotRegistered, NotAttestor
set_supply_witness(asset, witness)	asset admin	Sets the one supply witness and clears the previous witness’s post

In v0 only the contract admin registers assets. Issuers claiming their own asset through stellar.toml, and a timelock on attestor changes, are planned for T2.

Posting

Function	Auth	Does
post_supply(asset, amount: i128, ledger: u32)	the witness	Records supply measured at ledger. Errors: NotRegistered, NoWitness, NegativeAmount, FutureLedger, StaleLedger
post_report(asset, attestor, report: Report)	the attestor	Appends a report to the attestor’s history. Errors: NotRegistered, NotAttestor, UnitMismatch, NegativeAmount, FutureTimestamp, FutureLedger, OutOfOrder

Reading (no auth, no writes)

Function	Returns
status(asset) -> Status	Status under the asset’s own max age and tolerance
status_with(asset, max_age_secs: u64, mismatch_tolerance_bps: u32) -> Status	Status under the caller’s (used by the guard)
asset(asset) -> Option<AssetConfig>	The asset’s configuration
attestors(asset) -> Vec<Attestor>	Current attestors
reports(asset, attestor) -> Vec<ReportEntry>	Kept history, oldest first
supply(asset) -> Option<SupplyPost>	The latest supply post

How Status is computed: Status rules.

Types

pub struct AssetConfig {
    pub asset_admin: Address,
    pub unit: Symbol,               // what the asset is backed by, e.g. USD
    pub max_age_secs: u64,
    pub mismatch_tolerance_bps: u32,
    pub witness: Option<Address>,
    pub registered_at: u64,
}

pub struct Attestor { pub address: Address, pub added_at: u64 }

pub struct Report {
    pub reserves: i128,
    pub reserves_unit: Symbol,
    pub liabilities: i128,          // as stated by the report, in token units
    pub as_of: u64,                 // Unix seconds the figures are as of
    pub ledger: u32,
    pub uri: String,                // where the full report document is
    pub sha256: BytesN<32>,         // SHA-256 of that document
}

pub struct ReportEntry { pub report: Report, pub posted_at: u64, pub posted_ledger: u32 }

pub struct SupplyPost { pub amount: i128, pub ledger: u32, pub posted_at: u64 }

pub struct Status {
    pub coverage_bps: u32,
    pub newest_age_secs: u64,
    pub attestor_count: u32,
    pub disagreement_bps: u32,
    pub supply_mismatch: bool,
    pub supply_age_secs: u64,
}

Events

Every write emits one event. The first topic is the event’s name in snake case; the other topics are the fields marked #[topic] in the source.

Event	Topics	Data
AssetRegistered	asset_registered, asset	asset_admin, unit, max_age_secs, mismatch_tolerance_bps
AttestorAdded	attestor_added, asset, attestor	at
AttestorRemoved	attestor_removed, asset, attestor	at
WitnessSet	witness_set, asset	witness
SupplyPosted	supply_posted, asset	amount, ledger
ReportPosted	report_posted, asset, attestor	reserves, liabilities, as_of, ledger, sha256

Errors

Error	Code
AlreadyRegistered	1
NotRegistered	2
AlreadyAttestor	3
NotAttestor	4
TooManyAttestors	5
NoWitness	6
UnitMismatch	7
FutureTimestamp	8
FutureLedger	9
StaleLedger	10
OutOfOrder	11
NegativeAmount	12
InvalidPolicy	13

When each one is raised: Status rules.

Storage

All entries are persistent and extended to the maximum TTL on every write to the asset, so status keeps working as long as the asset is in use.