FX Revaluation

The gate

The script refuses to produce a clean revaluation workbook when:

1. A row has no explicit monetary flag. monetary must be y or n per row, stated by the client. A blank is an exception, never assumed to be "no" — guessing wrong here means a real monetary balance never gets revalued.
2. A row flagged monetary=y has no period-end rate for its currency. The rate table is client-supplied; a missing currency is a visible exception, never defaulted to 1.00 and never interpolated from a nearby currency or period.
3. The proposed revaluation JE doesn't balance. Each row's entry — the account moving to its new functional-currency value, offset by FX Gain/(Loss) — is self-balancing by construction; a failure here means something upstream is broken and the workbook should not go out.

Nonmonetary accounts (monetary=n) are never silently dropped. They're logged to their own tab so a reviewer can see exactly what was excluded and why, rather than wondering whether an account was missed.

Inputs

1. GL detail by currency — account, currency, the foreign-currency amount, the functional- currency amount currently recorded, and an explicit monetary/nonmonetary flag per row.
2. Period-end spot rates by currency.
3. Settlement detail (optional) — foreign-currency items that settled during the period, so their gain/loss is classified realized rather than unrealized.
4. The beginning CTA balance, to roll forward.

Step 1 — Build the worksheet

python3 scripts/fx_revaluation.py --gl gl_detail.csv --template --out gl_worksheet.csv

Step 2 — Run the revaluation

python3 scripts/fx_revaluation.py --gl gl_worksheet.csv --rates rates.csv \
  --beginning-cta -42500.00 --settlements settlements.csv \
  --client "Northwind Systems Inc" --period-end 2025-12-31 \
  --out "Northwind - Q4 2025 FX Revaluation.xlsx"

Deliver

Workbook tabs:

1. Workpaper Summary — unrealized and realized gain/loss totals, the CTA rollforward, whether the proposed JE balances, and the conclusion.
2. Revaluation Workbook — every monetary row with its FC amount, old and new functional equivalents, the period-end rate applied, the gain/loss, and realized/unrealized status.
3. Proposed JEs — the balanced two-line entry per account with a nonzero revaluation effect: the account itself moving to its new value, offset by FX Gain/(Loss).
4. CTA Rollforward — beginning CTA, the period's unrealized translation adjustment, ending CTA.
5. Nonmonetary Accounts Excluded — the transparency log of every account flagged monetary=n.
6. Exceptions — every missing rate, unstated flag, or unparseable amount.

Then, in chat: total unrealized and realized gain/loss first, then the CTA rollforward, then any account whose gain/loss is unusually large relative to its balance.

What to escalate

• A large gain/loss relative to the account's recorded balance — the script flags these as judgment items; confirm the rate, the FC amount, and whether the account was already partially revalued elsewhere before accepting the figure.
• An account the client flagged monetary=n that functions like a monetary balance (an intercompany loan booked to a balance-sheet-only account, for instance) — report what the flag says and what the account appears to be, and let the engagement decide the classification.
• A settlement whose settlement_rate differs sharply from the nearby spot rate, which can indicate a forward contract, a hedge, or a data entry error — not something this skill resolves.
• Any currency with a rate the engagement hasn't independently verified for the period — this skill applies whatever rate you give it and recomputes faithfully; it does not validate the rate itself.

Report each as a fact with the account and currency. Do not characterize intent.

Security posture

Fully local: standard library plus openpyxl. No network calls, no uploads, no telemetry. GL and currency data never leave the machine.

Dependencies

pip install openpyxl

Built by Adopt AI — free to use and modify.