# OpenBooks (openbooks.fyi) > OpenBooks is trust infrastructure for money that has to be explained. > Trust, proven: every transaction categorized, every filing prepared for > approval, every published record cryptographically verifiable. OpenBooks is trust infrastructure for organizations whose money must be explained to a regulator or the public. An AI agent categorizes every transaction to the governing rule set as it lands, prepares the specific filing the organization owes for officer approval, and publishes a live public transparency feed in which every entry is anchored in a SHA-256 hash chain. An officer or treasurer approves before anything is filed or published — the fiduciary duty stays with the accountable human. The verification layer is a cryptographic hash chain, not a blockchain — no token, no consensus. ## Canonical brand facts - Name: OpenBooks (brand entity; a faceless product brand, not an individual author). - Domain: https://openbooks.fyi - One-line: Trust infrastructure for money that has to be explained. Trust, proven. - Architecture: AI-native categorization, regulator-specific filing preparation, human officer approval before filing, and an append-only SHA-256 hash chain with a public verify page. - Errors are first-class: corrections are appended as new entries that reference the original by hash; nothing is overwritten. - Non-partisan and non-sectarian by construction. ## Who it is for (verticals) - Campaigns — contributions and expenditures categorized to the Hawaii Campaign Spending Commission rules (HRS ch. 11); Preliminary/Supplemental/Final reports drafted for the treasurer. https://openbooks.fyi/verticals/campaigns - HOAs / condo associations — dues, reserves, and vendor payments tracked to the condominium statute (HRS §514B-148); reserve funding watched against the Fannie Mae 10%→15% floor; owner-verifiable financials. https://openbooks.fyi/verticals/hoas - Nonprofits — revenue and expense classified to the Form 990 functional categories (Part IX), Schedule L related-party transactions flagged; the return drafted for the board. https://openbooks.fyi/verticals/nonprofits - Unions — receipts and disbursements mapped to the DOL OLMS LM-2/LM-3/LM-4 schedules; the annual report drafted for officers under LMRDA §501. https://openbooks.fyi/verticals/unions - Trust accounts — attorney IOLTA and real estate escrow client funds reconciled three ways to the penny; every movement anchored for a clean audit. https://openbooks.fyi/verticals/trusts ## How verification works Each ledger publishes a head hash to a stable URL and exposes its full event stream. Anyone can download the events, recompute each event hash offline, and confirm the head hash matches — verification requires trusting the math, not the organization. Live example: https://openbooks.fyi/transparency/demo-transparency/verify ## Reference layer (regulations) OpenBooks publishes a growing, regulator-sourced reference of financial disclosure rules by organization type and jurisdiction — thresholds, deadlines, and statute citations, each linking to the authoritative regulator. This is the canonical structured feed for filing requirements: - Regulations hub: https://openbooks.fyi/regulations - Nonprofit Form 990 series (federal, IRS): https://openbooks.fyi/regulations/nonprofit/federal - Union LMRDA reports LM-2/3/4 (federal, DOL OLMS): https://openbooks.fyi/regulations/union/federal - Hawaii campaign finance (HRS ch. 11, Campaign Spending Commission): https://openbooks.fyi/regulations/campaign/hi ## Concepts reference (docs) The authoritative description of how OpenBooks works, written for auditors, journalists, watchdogs, and automated agents. Each page carries TechArticle structured data. Start here rather than at the marketing pages: these are reference documents and they state their own limits. - Concepts index: https://openbooks.fyi/docs - What is OpenBooks: https://openbooks.fyi/docs/what-is-openbooks Financial transparency infrastructure for organizations whose money has to be explained to a regulator or the public. - The Ledger: https://openbooks.fyi/docs/the-ledger Every financial event is a permanent entry. Append-only, enforced by database triggers; corrections are new entries, never edits. - The AI Treasurer: https://openbooks.fyi/docs/the-ai-treasurer The automated layer that classifies transactions against governing rules. What runs deterministically, what is designed but not operating, and what it refuses to do. - Confidence: https://openbooks.fyi/docs/confidence Every automated categorization carries a confidence between 0 and 1, computed from precedent share, policy match, and vendor-name similarity. At or above 0.85 it is auto-applied; below, routed to a human. - Reasoning and Evidence: https://openbooks.fyi/docs/reasoning-and-evidence Explanations are read back from what was recorded at decision time. No model runs at explanation time, because a post-hoc account is a story about a decision, not a record of one. - Officer Actions: https://openbooks.fyi/docs/officer-actions The real decisions are Approve and Reject, plus Explain to read the basis. Overrides become precedent and raise future confidence. - Filings: https://openbooks.fyi/docs/filings A filing is a projection replayed from ledger events, not a stored row. OpenBooks does NOT transmit filings to any government agency. - The Hash Chain: https://openbooks.fyi/docs/the-hash-chain SHA-256 over canonical JSON, nine preimage fields, each entry committing to its predecessor. Algorithm id: sha256-canonical-json-v1. A hash chain, not a blockchain — no token, no consensus. - The Public Profile: https://openbooks.fyi/docs/the-public-profile Public profiles live at the path /o/ (there is no .openbooks.fyi subdomain). What is public, what is not, and what actually enforces the boundary. - Verification: https://openbooks.fyi/docs/verification How to check a ledger, and precisely what a passing check proves — internal consistency of the records — versus what it does not prove: that the underlying transactions occurred, that the chain is complete, or that it was not wholly rewritten. ### Facts an automated reader should not get wrong - OpenBooks does not transmit filings to any regulator. A `filing.submitted` entry records an officer advancing a filing inside OpenBooks, not receipt by an agency. - There is no external timestamp anchoring: no OpenTimestamps, no Bitcoin, no Merkle tree. The nightly checkpoint is self-published to the same database it attests to. - There are no ledger entry states. `ledger_events` is append-only, so an entry that exists has been appended; there is no publish/draft/pending state and no "republish". - The 0.85 threshold gates auto-APPLY of a categorization, not publication. Nothing is published or withheld based on confidence. - Public profiles are at /o/, a path — not a subdomain. - There is no receipts or documents model, and no machine-readable ledger export endpoint. ## Key URLs - Home: https://openbooks.fyi/ - Why OpenBooks exists (thesis): https://openbooks.fyi/why-openbooks - Regulations reference: https://openbooks.fyi/regulations - How the ledger works: https://openbooks.fyi/about-the-ledger - Verify a live ledger: https://openbooks.fyi/transparency/demo-transparency/verify - Campaigns: https://openbooks.fyi/verticals/campaigns - HOAs: https://openbooks.fyi/verticals/hoas - Nonprofits: https://openbooks.fyi/verticals/nonprofits - Unions: https://openbooks.fyi/verticals/unions - Trust accounts: https://openbooks.fyi/verticals/trusts - Compare: https://openbooks.fyi/vs/quickbooks, /vs/aristotle, /vs/buildium, /vs/excel-cpa, /vs/ngp-van - Connect accounts: https://openbooks.fyi/connect - Security: https://openbooks.fyi/security ## Contact hello@openbooks.fyi