swaitsandClaude Opus 5.5
ad572ae89d
Stephen asked that specs come from recognized documents, not from anyone's memory. There is no single US bookkeeping bible; authority is layered, and this records it: - docs/spec/sources/: verbatim excerpts (whitespace normalized), each with URL, retrieval date, and the SHA-256 of the fetched file, of public-domain texts: Pacioli's 1494 treatise in Geijsbeek's 1914 translation (double entry, the trial balance, one money, write only forward, correct by opposite entry, close into capital); IRS Pub. 583, 538, 946, 15; the 1099-MISC/NEC instructions (2025 and 2026); 26 U.S.C. §6041, §6041A, §704; Treas. Reg. §1.263(a)-1(f) and -4(f); Notice 2015-82; Rev. Proc. 98-25; Form 1065 instructions; 17 U.S.C. §105. The excerpts were extracted by matching each passage against the fetched file, so none can contain text the source doesn't. - docs/spec/rules.md: the rule catalog, B-1 to B-22. Each rule says AUTHORITY, CONVENTION, or DECISION; cites its sources (FASB's Codification and Concepts Statement 8 and OpenStax quoted briefly, never copied: copyright and CC BY-NC-SA); and names the code that enforces it and the tests and proofs that check it. - Spec blocks in the code now carry SOURCE: lines into the catalog; AGENTS.md makes sourcing rule 0 of the formal-methods bar. Corrections the sources turned up: the de minimis limit is $500 in the regulation and $2,500 by Notice 2015-82 (both now cited); 1099 thresholds after 2026 are inflation-indexed, so the engine's flat $2,000 for 2027+ is an open question (B-19). Unverified ASC paragraphs (360-10-35-4, 340-10, 230-10-45-10, 606-10-55-37B, 210) are listed in docs/spec/README.md until someone with a FASB basic-view login reads them. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
wanderbooks
Canonical double-entry bookkeeping, rebuilt from scratch. The engine is verified against oracles, parity is tracked automatically, and the primary interface is AI-first: you talk to an agent, the agent drives the books through MCP. Self-hosted, no rent.
What it is
ledger-core— the semantics engine. Exact decimal money, five account types, balanced journal entries, immutable posted log with reversing entries, trial balance, P&L, balance sheet, indirect-method cash flow, fixed-asset register with straight-line depreciation.ledger-store— durable storage. The source of truth is an append-only, hash-chained JSONL journal; SQLite is a disposable projection rebuilt from it; receipts live in a content-addressed blob store. Drafts are durable, corrupt projections self-heal.ledger-mcp— the AI-first interface. 64 MCP tools over stdio or Streamable HTTP: draft → preview → post workflow, server-side receipt policy (>$25), anti-splitting detection, asset management, digest for human review, plus read-only resources for dashboards.ledger-import— QuickBooks interop. Import bank/credit-card CSVs and chart-of-accounts CSVs; export IIF journal entries (for QuickBooks Desktop) and XLSX reports.ledger-config— the company settings in a books dir'swanderbooks.toml.ledger-gui— the viewer: a read-only, live window on the books for owners and their accountant (egui). Answers first (cash, runway, profit, what needs attention), then every number drills down to its lines, its entry, the rendered receipt, and the journal history. Follows the journal live: a change the agent makes appears in milliseconds.--demoopens a realistic demo company.
Verification
This is the storytold way applied to accounting: agents verify against oracles, never ship what they haven't demonstrated.
- 190+ workspace tests: invariant tests encoding accounting law, golden-file report snapshots, property tests (proptest), end-to-end MCP stdio tests.
- Formal proofs of the accounting laws (
just prove,docs/verification.md). Kani model-checks the engine's arithmetic kernel exhaustively within bounds. Lean 4 proves that, after any sequence of commands, the trial balance balances, the accounting equation holds, posted entries are forever, closed periods stay frozen, and a close moves exactly the net income to equity. The first pass found three engine bugs that every test, fuzzer, and mutant had missed: negative amounts accepted, and two crashes on oversized amounts. It also caught a soundness bug in the model checker itself. - Mutation testing via cargo-mutants; fuzzing via cargo-fuzz (11.5M+ executions, zero crashes).
- GnuCash is a behavioral cross-check, never the authority and never a code source (clean room, MIT OR Apache-2.0). Accounting principles, proved, are the spec. Where any other program disagrees, we work out from principles who is right.
Status
Parity is 12 of 12 against the spreadsheet workflow it replaces
(docs/capability-parity.md). The parallel-run plan
(docs/parallel-run.md) is written; the Google Sheet stays the system of
record until a clean month and explicit cutover approval.
See plan/STATUS.md for where things stand and
plan/roadmap.md for where it's going.
Quickstart
cargo test # whole suite
cargo run -p ledger-mcp -- --data-dir /tmp/books # MCP server over stdio
cargo run -p ledger-gui -- --demo # the viewer, on a demo company
New books, one command (installs Rust and wanderbooks if needed, makes the books dir with the MCP server registered for it, and starts the agent):
curl -fsSL https://wanderbooks.ai/install.sh | sh -s -- ~/Books/Acme
Already installed: wanderbooks new ~/Books/Acme (add --codex to keep the
books with Codex instead of Claude Code). In a books dir, just
lists the shortcuts (just gui, just agent, just backup).
Developing
Every tool the recipes use (Rust, just, Kani, Lean, cargo-mutants,
cargo-fuzz, Node for deploys) is pinned in mise.toml:
mise install
just # lists the recipes: check, build, prove, demo, ...
Layout
crates/ledger-core/ # engine: money, accounts, journal, ledger, reports
crates/ledger-store/ # journal + SQLite projection + blob store
crates/ledger-mcp/ # MCP server: 64 tools, resources, receipt policy
crates/ledger-import/ # QBO CSV import, IIF/XLSX export
crates/ledger-config/ # wanderbooks.toml company settings
crates/ledger-cli/ # `wanderbooks new`: one-command books dir + agent
crates/ledger-gui/ # the viewer: read-only, live (egui)
docs/ # requirements, architecture, oracle, parity, glossary
plan/ # STATUS.md, roadmap.md
AGENTS.md # operating manual for agents working here
License
MIT OR Apache-2.0. See LICENSE-MIT and LICENSE-APACHE.