Maurice
7da0080557
* docs(wiki): correct the install and operations pages for 4.0.0 Quick Start passed docker an empty ENCRYPTION_KEY: an assignment prefix is not expanded on the same command line, so the server silently generated its own key instead of taking the one the page told you to set. The tag examples pinned to the 3.x line, the documented tmpfs size did not match the shipped compose file, and several .env values were described as reaching the container when compose never interpolates them. * docs(wiki): match the MCP reference to the registered surface The scope table was missing the whole Collections group and the totals said 27 scopes across 13 groups where the code registers 29 across 14. The Cloudflare link on the setup page pointed at an anchor on its own page instead of the heading on Troubleshooting. * docs(wiki): correct the plugin and admin pages Three links to Plugin-Development carried a .md suffix, which does not resolve on the wiki. The admin pages described tabs, permissions and storage behaviour that had moved on. * docs(wiki): bring the feature pages back in line with the app Costs still documented the old panel, where categories could be added, renamed, reordered and deleted; they are fixed now and the panel is a day-grouped ledger with settlements. Trip sharing, journeys, maps, packing, reservations and the account pages had all drifted in the same way. * docs(wiki): cover the pages the first pass did not reach The MCP catalog listed 168 of the 201 registered tools; the settlement tools and rate_place were missing here and the Collections family from the addon page. Several resource rows claimed a trips:* scope where the handler asks for trips:read. * docs(wiki): tighten the corrections a review picked apart The audit-log resource is the row id, not the credential id; an admin password reset does not bump password_version the way the page implied; and a few of the new paragraphs described behaviour more confidently than the code supports. * docs(wiki): fix what a last read-through caught Costs shows every figure in your display currency, not the trip's, and an expense with no payer still counts against the members it is split between. Studio's cutoff is a 1024px viewport rather than phones alone, and the Integrations tab is gated on the providers an admin has configured. * docs(wiki): the last few the review caught A passkey satisfies the MFA policy everywhere except the WebSocket handshake, which still asks for TOTP, so a passkey-only account under that policy gets no live updates. Mobile optimizes a day from two places, not three. The ctx.db row carried an unescaped pipe that split the table, and the Backups table linked with a wiki link whose pipe did the same.
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Currencies
TREK has three currency settings, and they answer three different questions. Most confusion about the Costs tab comes from mixing them up, so this page is the one place they are defined together.
| Setting | Where | Question it answers | Affects |
|---|---|---|---|
| Trip currency | Trip → Edit trip | What is this trip's money? | Stored data — the base every balance is calculated in |
| Expense currency | Costs → expense modal | What currency did I actually pay in? | Stored data — that one expense |
| Display currency | Settings → General | What currency do I want to read? | Presentation only — never the stored data |
The short version: the trip currency is the accounting base, the expense currency is the receipt, and the display currency is your reading glasses.
Trip currency
Every trip has exactly one currency. It is set when you create the trip and can be changed later in the trip edit dialog (requires the trip_edit permission). The new-trip dialog pre-fills it with your display currency, falling back to EUR when you have left that on Trip currency. This is the one moment the display currency touches stored data: it seeds the field, and from then on the trip's currency is its own.
This is the trip's accounting base. It is not a cosmetic label:
- Every balance, debt and settle-up suggestion is calculated in it.
- Every expense in another currency is converted into it and stored with the rate it was converted at.
- It is what the Costs tab falls back to when nobody has expressed a display preference.
Pick the currency of the place you are travelling to (or the one you will actually settle up in), and you will rarely think about currencies again.
Changing the trip currency
Changing it is not a relabelling — it is a re-basing, and TREK does the work for you so that no money moves:
- Expenses that had no currency of their own (they simply inherited the trip's) are pinned to the old currency first. A 9 000 ₽ expense on a trip switching from RUB to EUR stays 9 000 ₽; it does not silently become 9 000 €.
- Every frozen exchange rate is re-anchored to the new base, because a frozen rate is stored relative to the trip currency (see below).
- Place prices are pinned the same way. A place price also inherits the trip's currency unless you gave it one of its own, so a €15 museum on a trip switching to JPY is stamped EUR rather than starting to read as ¥15.
The numbers you typed are never rewritten. Each expense keeps its original amount, in its original currency, and its real-world value survives the switch — only the base the balances are expressed in changes.
Expense currency
Each expense in the Costs tab carries its own currency, chosen in the expense modal. Enter what the receipt says: a $100 dinner on a rouble trip is entered as 100 USD, not as its rouble equivalent.
When an expense's currency differs from the trip currency, TREK looks up the live rate once, at the moment you save it, and freezes it on the expense. That frozen rate is what converts the expense into the trip currency forever after.
Why freeze it? Because a debt settled today shouldn't reopen tomorrow. If balances were recomputed at live rates, a settled-up trip would drift back into a few cents of debt every time the FX market moved. The rate you booked at is the rate you owe at.
Rates come from Frankfurter (European Central Bank data, no API key needed). 165 currencies are supported. If the rate lookup fails (the instance is offline, or the upstream is down), the expense is stored without a frozen rate and falls back to live conversion when it is next read — TREK never invents a rate.
Settle-up payments
A payment recorded in Settle Up also carries its own currency, for the same reason: settling a rouble debt with a euro transfer is perfectly normal. Its rate is frozen at the moment you record it, exactly like an expense's, so the payment keeps cancelling the debt it was meant to cancel.
Display currency
Settings → General → Currency is a per-user, presentation-only preference. It converts what you read in the Costs tab — totals, the category chart, balances, the settle-up amounts — into a single currency, so a trip with dollars, yen and roubles in it still adds up to one number you understand.
It never changes what is stored. Two people looking at the same trip can read it in different currencies and both see correct, consistent balances.
It has two modes:
| Value | Behaviour |
|---|---|
| Trip currency (the default) | Each trip is shown in its own currency. A Tokyo trip reads in yen, a Moscow trip in roubles. |
A specific currency (e.g. USD) |
Every trip is converted into that currency for you, whatever its own currency is. |
Leave it on Trip currency unless you specifically want everything in your home currency regardless of where you are going.
An administrator can set an instance-wide default (Admin → User Defaults), and it interacts with Trip currency: picking Trip currency stores an empty value, and an empty value on a defaultable setting counts as "not set", so the admin's currency is applied again (#1634). While an instance-wide default currency is configured, there is no way back to per-trip currencies from the Settings page — the admin has to clear it.
Display conversion uses live rates, not the frozen ones — it is a view, and a view should reflect today. This is why a converted total can shift slightly day to day while the underlying balances stay rock steady.
How they fit together
An expense flows through all three:
100 USD ≈ 7 668 ₽ ≈ 87 €
┌───────────┐ frozen ┌───────────────┐ live ┌───────────────┐
│ expense │ ─────────► │ trip │ ─────────► │ display │
│ currency │ rate │ currency │ rate │ currency │
└───────────┘ (at entry)└───────────────┘ (at read) └───────────────┘
what you what the trip is what you read,
actually paid settled in ← balances if you asked for
live here a display currency
Balances are always netted in the trip currency and converted to your display currency once, at the end — never per-expense. That ordering is deliberate: netting in a moving display currency would let rounding drift shuffle a settled trip into phantom one-cent debts.
The public share link
A public share page has no logged-in viewer, so it cannot use "your" display currency. It uses the sharer's display currency, falling back to the trip's own currency — i.e. a guest sees the trip the way the person who shared it sees it. If the sharer left their display currency on Trip currency, guests read the trip in the trip's currency.
Relationship with the Costs addon
The trip currency lives on the trip itself, not in the Costs addon — it is set in the trip dialog and remains set even if Costs is disabled. Expense currencies, frozen rates and settle-up all belong to Costs (addon id budget), which an admin can toggle in Admin-Addons. Turning Costs off hides the money features; it does not clear the trip's currency.
Changing the trip currency requires trip_edit. Adding or editing expenses (and their currencies) requires budget_edit. See Admin-Permissions.
Troubleshooting
"My balances are huge / nonsense on a trip with a foreign expense." Fixed in v3.4.0 (#1543). The settlement was reading the trip currency incorrectly and treating every trip as EUR, which inflated balances on any non-EUR trip that had a foreign-currency expense. Upgrade; no data was damaged and nothing needs fixing by hand.
"The totals move slightly from day to day." Expected, if your display currency differs from the trip currency: the display conversion uses live rates. The underlying balances and debts do not move.
"An expense shows an odd converted value." Its rate was frozen when it was entered, and the market has moved since. That is by design — see the note above.
See also
- Budget-Tracking — the Costs tab
- Creating-a-Trip — where the trip currency is set
- Display-Settings — where the display currency is set
- Public-Share-Links
- Admin-Addons