openbooks.fyi
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Transparency you can independently verify.

Every entry openbooks.fyi records — contribution, expenditure, filing, or classification — is chained with SHA-256 to the entry before it. A nightly checkpoint publishes the head hash so anyone can independently verify the record over time. This is a cryptographic hash chain, not a blockchain: no token, no consensus, no marketing.

Verify this ledger — live demo

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How it works

  1. Every write to a tenant's books produces one ledger event with the payload, actor, and timestamp.
  2. The event is hashed with SHA-256 over a canonical JSON encoding that also folds in the previous event's hash.
  3. The database blocks UPDATE and DELETE on the events table via an immutability trigger; the chain is append-only.
  4. Every night the head hash is anchored to a stable URL and, when configured, submitted to OpenTimestamps.
  5. Anyone with the tenant slug can independently recompute the chain and compare — instructions on each verify page.

Explore the endpoints: /api/ledger/demo-transparency/head · /verify?from=0 · /anchor.json · human page

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