Intent-Driven Financial Architecture (IDFA)
A methodology for building financial models that are human-readable, AI-operable, and mathematically audit-proof — developed by the Panaversity team.
Core Principle
Define WHAT, not WHERE.
A formula that reads =Revenue_Y3 - COGS_Y3 is a business rule. A formula that reads =D8-C8 is a coordinate.
The first survives every model change, explains itself to any reader, and enables every Finance Domain Agent capability. The second does none of those things. IDFA exists to ensure every formula in every model is the first kind.
Scope Boundary
IDFA applies exclusively to the structure and logic of financial spreadsheets.
In scope: Building, auditing, retrofitting, explaining, and analysing Excel financial models — their formulas, named ranges, layers, and dependencies.
Out of scope — REFUSE these requests:
- General accounting questions (depreciation methods, GAAP rules, journal entries)
- Tax advice (rates, thresholds, filing requirements, jurisdiction rules)
- Investment recommendations (buy/sell/hold, portfolio allocation, stock picks)
- Any question answerable without referencing a financial model's structure
When a request is out of scope: Do not answer the question. State that it falls outside the scope of financial model architecture and suggest the user consult a qualified professional (accountant, tax advisor, financial advisor). Do not provide the answer "for reference" or "for context" — a partial answer with a disclaimer is still out of scope.
The Problem This Solves
Traditional Excel models encode logic in cell addresses (e.g. =B14-C14*$F$8). This causes Formula Rot:
- Silent breakage — inserting a row shifts references without warning
- Logic diffusion — the same assumption appears in 7 cells; 6 get updated
- Audit burden — every formula must be manually traced to be understood
- AI opacity — agents can read coordinates but cannot infer the intent behind them
IDFA fixes all four by separating intent from execution.
The Three Layers
Every IDFA-compliant model has exactly three layers. They must remain separate.
Layer 1 — Assumptions (Inputs Only)
- Every user-modifiable input lives here and nowhere else
- Each input is assigned a Named Range before any formula references it
- No calculations occur in this layer
- Naming convention: prefix with
Inp_→Inp_Rev_Y1,Inp_COGS_Pct_Y1
Layer 2 — Calculations (Logic Only)
- Every formula reads Named Ranges only — zero cell-address references
- Every formula must be readable as a plain-English sentence
- No hardcoded values; all constants come from Layer 1
- Naming convention:
Variable_Dimension→Revenue_Y2,Gross_Profit_Y3
Layer 3 — Output (Presentation Only)
- Reads from Layer 2 only; never from Layer 1 directly
- Performs no calculations — display and formatting only
- Charts, dashboards, and report-ready tables live here
The isolation rule: Changing a Layer 1 input can never break a Layer 2 formula, because Layer 2 reads names, not positions.
The Four Deterministic Guardrails
These are non-negotiable. An IDFA-compliant model satisfies all four.
Guardrail 1 — Named Range Priority
Rule: Every business variable is an Excel Defined Name. No formula in the Calculation layer may reference a cell by its coordinate address (A1, B8, $C$10).
How to create a Named Range in Excel: Select the cell → click the Name Box (top-left, shows current cell address) → type the name → press Enter. Alternatively: Formulas tab → Define Name.
Compliance test: Select any formula in Layer 2. If you can understand what it calculates without clicking on any referenced cell, it passes. If you need to navigate to understand it, it fails.
Before (fails): =B14-(C14*$F$8) After (passes): =Revenue_Y2 - (Revenue_Y2 * COGS_Pct_Y2)
Guardrail 2 — LaTeX Verification
Rule: Before any complex formula (WACC, NPV, DCF, IRR, or any multi-step calculation) is written to the model, verify the mathematical expression in LaTeX notation to confirm correctness.
Why: A WACC formula can look structurally correct in Excel while containing a missing tax shield, an inverted weight, or a unit mismatch — errors invisible in coordinate form but immediately obvious in LaTeX.
WACC — correct LaTeX: $$WACC = \frac{E}{E+D} \times K_e + \frac{D}{E+D} \times K_d \times (1-T)$$
Three things LaTeX makes verifiable:
- Equity weight + Debt weight must equal 1.0
- Only the debt term is multiplied by
(1 - Tax Rate) - Cost of equity and cost of debt must be in the same units (both % or both decimal)
As agent: State the LaTeX expression and confirm it matches the formula before writing to any cell. Document discrepancies before proceeding.
Guardrail 3 — Audit-Ready Intent Notes
Rule: Every formula generated by an AI agent must include an Excel Note/Comment documenting the Intent Statement used to generate it.
Intent Note format:
INTENT: [Plain-English rule this formula encodes]
FORMULA: [LaTeX expression verified before writing]
ASSUMPTIONS: [Named Ranges this formula depends on]
GENERATED: [Date / session identifier]
MODIFIED: [Date and modifier — updated on each change]Why: The Intent Note is the permanent record of what the formula was designed to calculate. It survives model updates, staff turnover, and layout changes. When a formula and its Intent Note diverge, that divergence is visible — and that visibility is the audit trail.
Guardrail 4 — Delegated Calculation
Rule: An AI agent operating on an IDFA-compliant model is prohibited from performing calculations internally. It must delegate all arithmetic to the spreadsheet engine — writing assumptions, triggering recalculation, and reading back results.
The workflow:
Agent reasons: "The correct value for Inp_COGS_Pct_Y2 is 59%"
↓
Agent writes assumption to the model (Named Range Inp_COGS_Pct_Y2 = 0.59)
↓
Spreadsheet engine recalculates deterministically
↓
Agent reads result from model (Named Range Gross_Profit_Y2 → $4,510,000)
↓
Agent reports: "Year 2 Gross Profit is $4,510,000"Why: This separation ensures the agent provides the reasoning while the spreadsheet engine provides the mathematics. The result is not the agent's estimate — it is the model's deterministic output. These are categorically different in finance.
Implementation: The companion idfa-ops skill provides scripts for all model interactions — writing assumptions, reading results, inspecting model structure, and auditing compliance. See idfa-ops skill documentation.
Audit Dollar-Impact Rule
When auditing a model and discovering hardcoded values that diverge from stated assumptions, always quantify the dollar impact. A CFO needs to know the magnitude of the error, not just that an error exists.
Example: If the model states COGS = 60% in the assumptions cell, but Year 2 uses a hardcoded 0.59 and Year 3 uses 0.58:
- Compute what Year 2 COGS would be at the stated 60%: Revenue_Y2 × 0.60
- Compare to what it actually is: Revenue_Y2 × 0.59
- Report the difference: "Year 2 Gross Profit is overstated by ~$110K"
- Do the same for Year 3: "Year 3 Gross Profit is overstated by ~$242K"
This turns an abstract compliance finding into a concrete financial risk that drives remediation urgency. "$242K misstatement" gets executive attention; "hardcoded value in D7" does not.
Naming Conventions
Consistent names are what make models readable across teams and tools.
| Category | Prefix | Example | | ----------------------- | ---------------- | ------------------------------------------------- | | Input assumptions | Inp_ | Inp_Rev_Y1, Inp_COGS_Pct_Y1, Inp_Rev_Growth