Signed reserve reports

Today a reserve report is usually a PDF. A person can read it; a computer can’t. Nobody can tell from the link alone how old it is, and if it stops being updated, nothing notices.

Assay proposes a small change: publish the same figures as a short JSON file, signed with a Stellar key, next to the PDF you already have.

What’s in one

{
  "sep": "reserve-report-v0",
  "asset": "YOURCODE:GYOURISSUER…",
  "as_of": "2026-09-30T23:59:59Z",
  "reserves": [{ "type": "cash", "amount": "1010000.00", "unit": "USD" }],
  "liabilities": { "supply": "1000000.00", "unit": "YOURCODE" },
  "attestor": { "name": "Your firm", "role": "auditor", "domain": "yourfirm.com" },
  "evidence": [{ "uri": "https://yourfirm.com/reports/2026-09.pdf", "sha256": "…" }],
  "signature": "…"
}

• as_of: the date the figures are true for. That’s how report age is measured.
• reserves and liabilities: what’s held and what’s owed, as text so no rounding creeps in.
• evidence: your existing PDF, with its fingerprint (SHA-256), so anyone can check the PDF wasn’t swapped later.
• signature: made with the attestor’s Stellar key.

Why sign it

A signature says who made the statement. Anyone can check it with free tools, and if a single figure is changed afterwards, the check fails. You can see that happen in Verify a report.

A signature does not prove the figures are true. It ties them to a named signer, which is what an audit trail needs.

Is it a standard?

It’s a draft. The format is written up as a proposed Stellar Ecosystem Proposal (SEP), and builds on two existing standards: SEP-1 (stellar.toml) and SEP-53 (signed messages). Read the draft.

Publishing one is optional, like the attestation_of_reserve field itself. The step-by-step guide for issuers and attestors is here.