Private Finance AI

Spreadsheets That Tie Out, Generated On-Device

A Royal Softworks whitepaper · AssistantGeneral

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Abstract

Finance teams handle material non-public information and live in spreadsheets — two facts that make cloud AI a poor fit. The data can't be pasted into a third-party SaaS box, and the generic chat tools are unreliable at producing a workbook whose formulas actually work. AssistantGeneral keeps financial data on the analyst's machine and generates validated spreadsheets and reports using a sandboxed code engine, with read-only access to the systems where the numbers live.

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1. Why cloud AI fails finance

Confidentiality. MNPI, deal data, and client financials are exactly the material that cannot transit a vendor cloud — for legal, fiduciary, and competitive reasons. Audit and SOX-adjacent controls also demand a defensible answer to "where did this data go?"

Correctness. Ask a generic chat assistant for a financial model and you frequently get a spreadsheet with broken references, circular calculations, or numbers that don't reconcile. In finance, a workbook that doesn't tie out is worse than no workbook.

2. Data stays on the device

AssistantGeneral runs the finance stack locally: the model, the document index, the embeddings, and the document generation engine are all on-device. A cloud model is attached only when policy permits. Financial documents ingested for analysis are indexed locally; nothing is sent to a vendor to be embedded or processed.

3. Spreadsheets that actually tie out

The document engine doesn't approximate a spreadsheet in Markdown — it generates a real .xlsx by writing Python (openpyxl, XlsxWriter, pandas, NumPy) that executes in a sandboxed Pyodide (WebAssembly) worker on the device. The design is built for numerical reliability:

• Layered construction — the workbook is built in stages rather than one fragile pass.
• Workbook validation — the math is checked; the engine enforces sensible, one-way calculation flow rather than emitting circular or hand-waved formulas.
• Surgical edits — changes are applied as targeted line-level edits, not full rewrites, so a small correction doesn't risk the rest of the model.
• The source file is never overwritten — edits are delivered as a separate copy, so an original model or template is always preserved.

The same engine produces .docx reports and .pptx board decks from a brief.

4. Analyze where the numbers live — read-only

AssistantGeneral connects to the systems finance teams already use — SQL databases (Postgres/MySQL), cloud storage (S3, Azure Blob, Google Cloud Storage, Dropbox, OneDrive), and business systems — through a connector layer that is read-only and SELECT-only by design. The agent can discover sources, inspect schema, run a read query, and pull figures into a reconciliation or model — without any ability to write back. For internal systems that aren't a built-in connector, a custom-connector builder wires them up.

5. Grounded narrative

Financial commentary — MD&A, board narrative, variance explanations — is generated grounded in the actual figures pulled, with the groundedness gate keeping claims tied to the data and the retrieved documents. Contract and filing analysis reuses the same clause-extraction and expiry-tracking capabilities the legal library provides, applied to financial agreements, leases, and covenants.

6. Repeatable, scheduled

The monthly close digest, the weekly KPI pack, the recurring reconciliation — these are assembled once in the visual workflow builder and run on demand or on a cron schedule. What starts as a few custom workflows becomes the finance function's reusable internal library.

7. The interface matches the work

A Finance UI preset presents a data-and-connector-forward layout with voice surfaces hidden — built around the connectors, the knowledge base, and document generation.

8. For the firm: governance

When a finance function standardizes on AssistantGeneral, the governance plane (on the firm's own server) provides a shared knowledge base of policies and templates, single sign-on, an audit trail, and a policy that pins seats to the on-device model and the approved connectors — so the controls story is as clean as the data-residency story.

9. Scope

AssistantGeneral accelerates the mechanical and repetitive parts of financial work — model and report generation, document extraction, read-only data pulls, reconciliations, and grounded narrative — under the analyst's review, on data that never leaves the machine. It is a productivity tool for finance professionals, not an unsupervised decision-maker.

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Evaluate it on a real model: generate a multi-tab budget from a brief, open it in Excel, and confirm the formulas are live and correct — offline. Contact Royal Softworks.