FX rates¶

Keep prices.bean filled with official rates, so every foreign amount converts to CHF the way the tax authorities accept. For VAT, a foreign amount is converted at the rate the ESTV publishes, either the monthly average or the daily selling rate, and you keep your choice for at least a tax period.¹ quints uses the daily rate and fetches it from the BAZG at full precision.

Keep rates current¶

quints prices sync                     # fill gaps and extend to today
quints prices sync --from 2026-01-01   # repair mode: re-check every day

Needs network. Every run extends each currency forward to today and fills interior gaps — days missing anywhere in the file's history are fetched too. Days the source has no rate for (weekends, holidays) are checked once and recorded in a ; quints: verified … comment in the file header, so they are never re-fetched. A day only counts as checked once a newer rate is in the file: today, before the source publishes, is asked again next time. The scan never reaches back more than ten years, the time books are kept,³ so a mistyped year in an old line can't start a century of requests. The file is written as rates arrive: interrupt a long backfill and the next run resumes where it left off. --from ignores the verified record and re-checks the whole range.

The BAZG API has no bulk endpoint — the fetch is one request per calendar day per currency, so a first backfill takes a while; a live per-currency progress bar shows how far along it is. Rates already in the file are never touched — manual overrides survive a sync, with any ; comment on their line. The file is replaced in one step, so a crash mid-write leaves the old file. A line below the first price that isn't a price (another directive, a stray note) is refused before anything is fetched, because the rewrite would drop it.

Which currencies to fetch, and from which source, comes from the ledger — the same commodity price: metadata bean-price reads, with the same syntax, so quints and the standard beancount tooling always agree on where rates come from:

2026-01-01 commodity EUR
  price: "CHF:beanprice_bazg/EUR"

Any beanprice source works — bundled ones by short name (ecbrates/EUR-CHF), third-party ones by module path — whether it serves bulk series or single days; quints drives it day-by-day when it has to. The full bean-price syntax is supported: fallback chains ("CHF:beanprice_bazg/EUR,ecbrates/EUR-CHF" — the first source that answers wins), inverted pairs (^ prefix stores the reciprocal rate), several quote currencies separated by spaces, and price: "" to opt a commodity out. quints additionally refuses rates quoted in the wrong currency, so a wrong ticker fails loudly instead of corrupting the file. A price: value quints can't parse is listed, the other currencies still sync, and the run then exits 1, so a currency never goes unfetched quietly.

When the ledger declares no priced commodities (or you run outside a ledger), a [prices] section in quints.toml supplies the plan instead — and --source MODULE forces a specific module either way:

[prices]
source = "ecbrates"             # ECB reference rates, "BASE-SYMBOL" tickers
currencies = ["EUR"]
tickers = { EUR = "EUR-CHF" }   # 1 EUR = x CHF

Why quints prices sync and not bean-price?¶

Both read the same commodity metadata and drive the same sources — bean-price works fine against a quints ledger, and quints' own beanprice-bazg source is tested against it. The difference is what happens around the fetch:

• The file is maintained, not just appended to. bean-price prints directives for you to paste; sync owns prices.bean — sorted, one entry per day, weekend echoes de-duplicated, manual overrides left alone.
• Gaps heal themselves. bean-price fetches the dates you ask for. Every sync run re-checks the whole history and fills any missing day, so a stretch lost to a laptop shutdown or a source outage doesn't stay missing silently. Days the source genuinely has no rate for (weekends, holidays) are recorded in the file header and checked exactly once.
• Interrupts are cheap. Rates are written as they arrive; killing a 2-year backfill loses at most one window, and the next run resumes.
• Full precision. bean-price --update rounds through the ledger's display_precision; sync writes the raw source rate (BAZG publishes five decimals), which is what the ESTV-accepted daily rate actually is.
• Daily rates, by day. quints converts at the official rate of the transaction day (the daily option of Art. 45 MWSTV), not the latest quote — so the unit of work here is "keep a complete daily series current", which is a loop and a file format, not a one-shot fetch.

Year-end revaluation¶

quints fx revalue --at 2026-12-31

Prints the year-end revaluation transaction:² unrealized FX differences on non-CHF balances, booked against the configured fx_gain/fx_loss accounts. Review it, paste it into books/<year>.bean. Like everything in quints, it's printed for review — never written into your books directly.

It is one step of the year-end sequence — quints close check says whether it is still outstanding; see Close the year.

For VAT amounts on foreign invoices, use quints vat convert instead of manual conversion.