Glossary

Each entry uses the same word as the rest of the docs.

Anchor. An institution that issues a fiat-backed token on Stellar, such as USDC, EURC or ARST, and redeems it for the underlying money.

API token. The secret a caller sends as Authorization: Bearer <token> to start a cycle through the orchestrator's REST API.

Attestation. A report by an independent accountant on an institution's reserves at a date. A coverage record adds regular evidence between attestations and does not replace them.

attestation_of_reserve. A SEP-1 field in an issuer's stellar.toml that holds a link to evidence of its reserves. An anchor points it at a page that names its registry.

Attested reserve source. A reserve source where the custodian signs each reserve balance. Solva checks the signature, and the trust in the figure sits with the custodian.

Audit. An independent examination of an institution's accounts and controls. A record is evidence an auditor can use. It is not an audit.

Commitment root. One value that stands for the whole customer list and its total. Changing or removing any balance changes it, and no balance can be read from it.

Coverage. The state in which reserves are at least what is owed, written R >= L. As a percentage, it is reserves divided by what is owed, cut off at two decimals and never rounded up.

Covered. The status of an asset whose latest record shows reserves at or above what is owed and is recent. Statuses belong to public record pages. The registry stores none, so today a reader works the status out from the record.

Custodial app. A wallet, exchange or other app that holds customer money and moves it over Stellar.

Custodian. The firm that holds an institution's reserves and, for an attested source, signs the reserve balances.

Cycle. One full run that reads the reserves, takes the customer list, builds a proof and publishes it to the registry. Cycles run on request today. The orchestrator's scheduler, off by default, runs them daily for the free plan and hourly for pro.

Growth bound. The rule that reserves may grow by at most 10 percent from one record to the next. The first record must state no growth.

Holder. Anyone who holds an anchor's token or keeps a balance with a custodial app.

Horizon. The Stellar network's HTTP API for accounts and balances. The read on chain reserve source reads reserve balances from it.

Inclusion check. The check a holder runs to confirm that their own balance was counted in a record. The registry on Stellar answers true or false.

Inclusion path. The values a holder needs to rebuild the commitment root from their own balance. For each level of the tree, it holds the neighbouring branch's value and total.

Institution. An anchor or a custodial app that publishes records to its own registry.

is_covered Coming soon. A contract call that answers in one read whether an asset is covered.

Ledger. One block of the Stellar network. Each record is tied to the ledger that included it, which serves as its timestamp.

Liabilities. What an institution owes its customers, the total of every customer balance. Plain pages call this "what is owed".

Merkle sum tree. The structure behind the commitment root. Each entry holds a hashed customer reference and a balance, and each branch carries the total of the balances below it.

Orchestrator. The Solva service that runs each cycle. It reads and checks the reserve balances, sends the inputs to the prover and publishes the proof.

Passkey. A sign-in key held on a person's device or security key. Its private part never leaves the device.

Passkey smart wallet. A smart wallet on Stellar controlled by a passkey. It can own an institution's registry, so only that institution can publish to it.

Previous reserves. The reserves total of the record before the current one. The proof uses it for the growth bound, and the registry checks it matches.

Proof. See zero-knowledge proof.

Proof id. A record's number in its registry. The first record is 1.

Prover. The Solva service that builds the zero-knowledge proof from the reserve figures and the customer list.

Public record page Coming soon. A web page for each institution and asset that shows its status and history, with a stable address an anchor can link from stellar.toml.

Read on chain reserve source. A reserve source that reads balances of Stellar accounts from the ledger, through Horizon, on every cycle.

Record. One entry in a registry, holding the reserves total, the liabilities total, the commitment root, the time and the proof id. It is written after the proof passes every check.

Registry. The contract on Stellar that belongs to one institution. It checks each proof and keeps that institution's records.

Reserve source. Where a cycle gets the reserve figures, from an attested custodian or, for a read on chain source, the Stellar ledger.

Reserves. The money an institution holds to back what it owes.

Sandbox. A stand-in custodian used by the public demo. Its signatures are real and its balances are synthetic.

Scoped publishing key. The orchestrator's key, added to the passkey smart wallet as a signer limited to one registry, so cycles can publish without a person present.

Selective disclosure Coming soon. Scoped access for one named party, such as a supervisor or an auditor, to more detail than the public record.

SEP. A Stellar Ecosystem Proposal, the name for a Stellar standard.

Short. The status of an asset whose latest cycle found reserves below what is owed. Such a cycle is refused, so there is no proof that day and no new record. Shown on public record pages.

Soroban. The smart contract platform on Stellar. The registry is a Soroban contract.

Stale. The status of an asset with no new record inside the expected window. Coverage is unknown until the next record. Shown on public record pages; today a reader applies the rule from the record's time.

stellar.toml. The file an issuer publishes on its domain to describe itself and its tokens, defined by SEP-1.

Tenant. An institution's entry in the orchestrator, with an id, a name and a plan.

Testnet. Stellar's public test network. Solva runs there today.

Verifier. The code in the registry that checks a proof on Stellar.

What is owed. See liabilities.

Zero-knowledge proof. A short piece of data that shows a statement is true. In Solva, it shows reserves cover what is owed, and no balance is a public input, so a record reveals none. The proof system's hiding setting, in development, also keeps the proof data from revealing anything about the private inputs. See Privacy.