MHM Currency Switcher

Changelog

2.1.0

• BREAKING: switcher CSS classes were renamed from mhm-cs-* to mhmcs-*.
  Every class in the switcher’s CSS and JS — .mhm-cs-switcher,
  .mhm-cs-dropdown, .mhm-cs-size--small, and the rest — now uses the
  mhmcs- prefix instead. If you have written custom CSS or JavaScript
  that targets one of the old mhm-cs-* classes, it will stop matching
  after you update: change your selectors to the new mhmcs- names. No
  alias is kept for the old classes.
• BREAKING: the mhmcs_fallback_rates_url filter’s $source argument is
  now always ecb. The exchange-rate fallback no longer has two stages
  (currency-api then frankfurter); it is now a single request to the
  European Central Bank’s daily reference feed. Code that checked for
  $source === ‘currency-api’ or 'frankfurter' will no longer see those
  values.
• BREAKING: the settings migration for sites still on a pre-1.0.0 install
  was removed, along with its matching legacy-license cleanup and the
  equivalent old-option branches in the uninstall routine. Every version
  released since 1.0.0 (2026-07) is unaffected; only a site that has never
  updated past the 2026-03 release would have skipped a migration it
  otherwise would have received on activation.
• Changed: the exchange-rate fallback is now a single European Central Bank
  request instead of the two-stage currency-api.pages.dev then
  Frankfurter chain added in 2.0.0. Coverage is unchanged — the same
  roughly thirty currencies — because that was already the final stage of
  the old chain; the extra intermediate stage is removed as no longer
  useful.
• Added: a snooze option for the two cache-compatibility admin notices.
  Dismissing a notice now clears it only for the specific problem currently
  detected — it comes back automatically if a new, different cache problem
  appears later, instead of going silent for good.
• Added: the WooCommerce-missing notice and both cache-compatibility
  notices now only appear on the screens where they belong, instead of on
  every admin screen. Capability requirements differ by notice: the
  WooCommerce-missing notice needs activate_plugins (the capability to
  act on it — you install a plugin), and the two cache-compatibility
  notices need manage_woocommerce.
• Fixed: every remaining mhm-cs- / mhm_cs_ / mhm_currency_switcher_
  legacy naming token still in the plugin — across CSS, JavaScript, the
  admin panel source and its compiled build, tests and documentation — has
  been renamed to the current mhmcs prefix. This is the last of the
  prefix cleanup that started with the 2.0.0 shortcode and option rename.
• Fixed: the public, unauthenticated GET /rates REST endpoint was
  removed. It duplicated information already visible in the page itself;
  the authenticated /rates/sync and /rates/preview endpoints used by
  the admin panel are unaffected.
• For developers: languages/ is no longer included in the release ZIP —
  WordPress.org compiles translations from the .pot file, which is still
  kept in the plugin’s repository.

2.0.0

• BREAKING: the two shortcode tags were renamed. [mhm_currency_switcher]
  is now [mhmcs_currency_switcher], and [mhm_currency_prices] is now
  [mhmcs_currency_prices]. The old tags are gone; a page still holding one
  will show the raw text instead of the switcher, so update any page, post or
  template that uses them. WordPress.org’s prefix check splits a prefix at the
  first underscore, which read the old tags as “mhm” — three letters, under
  the four-letter minimum — and a plugin cannot be reviewed under a name the
  review tool cannot attribute to it. Stored data is untouched: option names,
  order meta and per-product fixed prices all keep the names they had.
• Changed: the fallback exchange rate source is served from a different host.
  Rates now fall back to latest.currency-api.pages.dev instead of the
  jsDelivr CDN. Same upstream project, same payload; only the host changed.
  WordPress.org’s review tool keeps a fixed list of public CDN domains and
  treats a shipped source naming one as an error, whatever the URL fetches.
  If your store restricts outbound requests to an allow-list, permit the new
  host — or redirect it with the filter below.
• Added: a SECOND fallback rate source, so a blocked network is no longer a
  dead end. The host serving the first fallback is unreachable from some
  national networks — Turkey, measured — and not merely by DNS: resolving it
  over DNS-over-HTTPS and connecting straight to the real addresses with the
  correct SNI still times out, while other hosts on the same infrastructure
  answer normally. A server there cannot route around it by changing
  resolvers, the old host cannot be restored (that is the rule above), and the
  upstream project documents no third mirror. The chain now ends at
  Frankfurter, a different provider serving European Central Bank reference
  rates: no API key, commercial use permitted, no attribution required. The
  trade is coverage — around thirty currencies rather than hundreds — which
  is the right trade for a source reached only after two others have failed,
  and the set includes the currencies shops actually price in.
• Added: a filter, mhmcs_fallback_rates_url, which receives the URL, the base
  currency code and which source is being filtered (currency-api or
  frankfurter), so a store can move one source without moving the others.
• Added: an About tab, with links to the documentation site, the WordPress.org
  support forum and the issue tracker, plus how to reach the developer.
• Added: the Advanced tab now says WHEN the next automatic rate update is due,
  not only how often it repeats. It gives the scheduled time in the store’s own
  timezone and format, how long that is from now, and states plainly that
  WordPress runs scheduled work on the first visit after that time rather than
  exactly on the hour.
• Fixed: currencies with no minor unit, or with three, were given two decimals.
  When a currency carried no explicit decimal setting the fallback was a fixed
  2 rather than the store’s own configuration, so a shop adding JPY saw
  100.00 and one adding BHD lost a digit. The table is derived from ICU’s
  minor-unit data; 37 of the 163 codes WooCommerce offers are not
  two-decimal currencies. No intl extension is required.
• Fixed: the Advanced tab claimed nothing was scheduled right after it
  scheduled something. Switching from “Manual only” to a recurring interval
  and saving armed the event, but the panel kept the schedule it had read when
  the page loaded and showed “Automatic updates are switched on, but no update
  is scheduled. Re-save this setting to schedule one.” Re-saving changed
  nothing; only reloading the page did. The save response now carries the
  schedule it armed.
• Fixed: saving unrelated settings moved the next rate update. The panel sends
  the whole settings form, and the scheduler asked whether the interval had
  been submitted rather than whether it had changed — so toggling anything on
  that screen re-armed the event at the current moment, shifting a daily
  store’s update time and making the next visit run a full sync. Saving now
  reconciles the schedule with the stored interval instead: it re-arms on a
  real change, restores an event that has gone missing while the setting still
  promises one, and clears one left standing behind “Manual only”.
• Fixed: rate-limited responses (HTTP 429) from the public conversion endpoint
  carried no cache headers, so a proxy or page cache could store a rejection
  and serve it to callers who were not over the limit.
• Fixed: the admin styles for the per-currency price fields on the product and
  variation screens moved out of the markup and into a stylesheet.
• Fixed: a translator note on one admin message was placed where the linter
  could not see it, so that string had been shipping without its note attached.
• For developers: the plugin’s source and build steps are now named in
  readme.txt, and every URL the About tab shows is a plain link with no
  tracking parameters.

1.3.1

• Fixed: a currency with no usable exchange rate could still be used for
  prices, and the amount and the currency it was shown in came from different
  decisions. A currency added in the panel starts at a rate of 0 until the
  first sync, and a per-product fixed price was applied under it while the
  symbol and code fell back to the base currency — a foreign amount wearing
  the base currency’s identity, on the catalogue and in the cart and the
  charge. Such a currency now resolves to the base currency everywhere, which
  is what the panel already said would happen.
• Fixed: the WooCommerce REST API (wc/v3) applied a per-product fixed price for
  that same unusable currency when one was asked for with ?currency=, while
  every other field in the response, and the currency a client reads it under,
  stayed in the base currency. Feeds, stock syncs and marketplace integrations
  took that price as fact.
• Fixed: orders placed in the shop’s own currency recorded an exchange rate of
  1. That field is the record of what the customer was charged, so anything
     reconstructing it — a report, an accounting export, a refund — had nothing
     to work from. New orders record a rate of 1. Orders already placed keep the
     value they were saved with.
• Fixed: a save that never reached the database was reported as a success.
  This affected the currency list, the settings screen, and all three ways
  rates are synced — the panel button, the hourly schedule and WP-CLI — and
  in the sync case the “last synced” time moved forward regardless, so the
  panel said the rates were current while it served the old ones. Every one of
  them now reports the failure, and saving again with nothing changed is still
  reported as a success.
• Fixed: upgrading from a pre-0.3.0 version could lose the currency
  configuration. The migration copied the old settings across, then deleted
  the originals and marked itself finished — without checking that the copy
  had been written. If it had not, there was nothing left and nothing tried
  again. It now leaves everything in place and retries on the next request.
• Fixed: the rate, fee and rounding fields accepted numbers that cannot be
  stored — text, a value too large to represent, or a negative rate — and a
  single one of them discarded every other currency in the same save. They are
  now corrected and the panel names each correction, as it already did for the
  decimal count.
• Fixed: a per-product fixed price entered as a number too large to represent
  was stored in a form that reads back as zero, which offered the product for
  nothing in that currency. A negative fixed price was accepted as well. Both
  are now refused, on the product page and the variation rows alike.

1.3.0

• Added: the settings screen was rebuilt. Currencies are now one table where
  each row carries its own rate, fee and rounding controls and shows the price
  a customer would actually see in that currency — computed on the server with
  the store’s own price formatter, not estimated in the browser.
• Added: a number format editor per currency — symbol, symbol position,
  decimals, and the decimal and thousand separators. WooCommerce stores one set
  of these for the whole shop because it assumes one currency; this plugin
  shows several. Until now the data was stored but there was no field to edit
  it with, so a currency saved with the wrong symbol — which happens when
  another multi-currency plugin is filtering WooCommerce at the time — could
  not be corrected from the panel at all.
• Added: a rate freshness indicator, on each currency row and on the Advanced
  tab. Where no sync has been recorded it says exactly that — “No sync
  recorded yet” — rather than claiming a sync never ran, so a shop upgrading to
  this version is not told its working rates are missing.
• Added: an option, off by default, to delete all of the plugin’s data when the
  plugin is removed. Left off, your settings and the currency and exchange rate
  recorded on each order survive uninstalling. Those records are the only basis
  for multi-currency sales history and cannot be rebuilt afterwards. On a
  multisite network the switch clears the site the plugin is removed from.
• Added: the “How to use” tab now documents the navigation menu item, and says
  plainly that Appearance → Menus only appears when the active theme supports
  menus or widgets, which most block themes do not.
• Added: Turkish translations for everything above.
• Fixed: an exchange rate below 1 could not be typed into the panel. Typing
  0.0211 left 211 in the field, and 0.05 left 5, without warning. A shop whose
  base currency is weaker than the currencies it sells in has no rate above 1,
  so the field could not take a single realistic value. The rate, fee and
  rounding amounts were all affected, in 1.2.0 as well. All of them now keep
  what you type.
• Fixed: the switcher preview on Display Options left out the base currency and
  ignored the “show currency symbol” toggle, so it showed a different list from
  the one a visitor gets. It now matches. The product price widget’s currency
  field, separately, shows how many of its five allowed currencies are chosen.
• Fixed: the product price list’s five-currency limit was enforced only in the
  browser. A sixth currency sent to the REST API was stored and then silently
  dropped when the list rendered. The server now applies the same limit and
  reports it instead of dropping the extra quietly.
• Fixed: a variable product’s advertised price range could be served from an
  old exchange rate. WooCommerce caches that range for up to 30 days, keyed by
  a hash this plugin only put the currency code into — so after a rate update
  the range kept coming from the old rate while every other price on the site
  used the new one. A shopper could read one range and be charged more than its
  top end. The key now includes the rate and rounding the amounts depend on.
• Fixed: GET /settings returned the whole stored option, including keys whose
  controls were removed in an earlier release. One of them, provider_api_key,
  is a credential you supplied. Saving settings has always dropped those keys,
  but a shop that had not pressed Save since then still held the value, and the
  read route handed it to anyone with the “manage WooCommerce” capability —
  which includes shop managers, who are not administrators. The read route now
  filters the same list the save route and the uninstaller do.
• Fixed: the currency picker’s popover did not close on Escape, and closing it
  did not return keyboard focus to the button that opened it.
• Fixed: values typed into the new format fields are corrected rather than
  silently accepted — a separator longer than one character, a decimal count
  outside 0 to 4, or identical thousand and decimal separators — and the screen
  names every correction it made instead of changing your input without saying.
• Changed: the REST API now refuses a save or preview request carrying more than
  500 currency rows, rather than accepting a payload of any size. The panel
  cannot produce such a request — WooCommerce offers 163 currency codes in
  total — so the guard only fires on something that did not come from it.
• Changed: the settings screen is wider, 1200px rather than 900px. Below that
  width the currency table stacks into one card per currency, each field
  labelled, rather than being cut off at the edge.

1.2.0

• Added: a “How to use” tab in the plugin’s settings screen. The plugin can be
  placed in five different ways — two shortcodes, two Elementor widgets and a
  navigation menu item — and none of them were named anywhere in the admin, so
  after adding currencies there was nothing to tell you why the switcher had
  not appeared on your site. The new tab lists every option with copyable code,
  a table of the price-list shortcode’s attributes, and a note that the
  Appearance → Menus route only exists on classic themes.
• Fixed: five labels in the currency picker on the settings screen were written
  in Turkish, so they stayed Turkish in every other language, English included.
  They are English now, and the Turkish wording moved into the Turkish
  translation file.
• Fixed: the navigation menu switcher printed its CSS class twice in the menu
  item’s class attribute. This was not visible on the storefront, but it was
  wrong.
• Fixed: when your browser does not allow a page to write to the clipboard, the
  copy buttons on the new tab select the code and tell you to copy it. That
  message named a Windows keystroke; it no longer names a key at all.

1.1.3

• Fixed: upgrading from a version older than 0.3.0 reset the plugin’s settings,
  and on a shop that had configured currencies it lost the currency list
  entirely. The option names changed in 0.3.0 without a migration, and the
  current names are only written when the plugin is activated — which does not
  happen during an in-place update. A one-time migration now carries the old
  settings and any configured currencies onto the current names, removes the
  old rows, and cancels the pre-0.3.0 rate-update task so it cannot keep firing.
  Sites that never configured anything simply get the standard defaults: the
  four currency codes the old installer wrote were in a format the plugin could
  never read, so they were never in use and are not carried over.
• Fixed: the Advanced tab showed “Daily” as the automatic rate-update interval
  on sites that had never chosen one, but nothing was scheduled — the setting
  screen and the scheduler disagreed about what an unset interval means. The
  screen now shows “Manual only”, which is what the plugin actually does until
  you pick an interval.
• Fixed: the multi-currency price display showed prices for currencies you had
  not configured, and the figure it showed was the base price wearing the other
  currency’s code and flag. On a shop with nothing configured, the Elementor
  price widget did this out of the box, because its default currency list is
  USD, EUR, GBP. Currencies you have not configured are now left out.
• Documented the [mhm_currency_switcher] and [mhm_currency_prices]
  shortcodes and their attributes, which this file advertised but never named.
• Fixed: on a shop running a second currency plugin, adding a currency could
  save it with the wrong symbol — every new currency picked up the symbol of
  whichever currency was being displayed, so a US Dollar currency could print
  your base currency’s sign on the storefront. New currencies now take their
  symbol from WooCommerce’s own currency table. Currencies added before this
  release keep whatever symbol was stored; if one of yours shows the wrong
  sign, remove it and add it again.

1.1.2

• Requires WordPress 6.6. The settings screen never loaded on 6.0 to 6.5:
  the admin bundle depends on a script handle WordPress only registers from
  6.6, and an unregistered dependency makes WordPress drop the script silently.
  Every release to date claimed 6.0 and none of them could show that screen on
  it. If you are on an older WordPress, staying on 1.1.1 keeps the storefront
  working — the conversion scripts have no such dependency — but the settings
  screen will not open there either.
• Fixed: every control in the currency table was unnamed for screen readers —
  the enable toggle, both rate controls, both fee controls and both rounding
  controls. Each now says what it changes and which currency it belongs to.
• Fixed: the currency picker was announced as an unlabelled button, because its
  visible label was never associated with the control.
• Declared compatibility with the Cart & Checkout Blocks. The plugin already
  worked with them — they read their amounts from the Store API, which is
  converted on the server — but without the declaration WooCommerce warned
  shop owners about the plugin on those screens.

1.1.1

• The settings screen no longer triggers WordPress’s deprecation notice for the
  36px control size; its selects and text fields opt into the 40px size that
  becomes the default in WordPress 7.1.
• Corrected the Plugin URI, which pointed at a page that does not exist.
• Declared WooCommerce as a required plugin, and corrected the tested-against
  WooCommerce range to the versions the test suite actually runs (7.4 to 10.9).

1.1.0

• Cache compatibility mode, on by default. Anonymous shop, archive and product
  pages are rendered in your base currency so a page cache can serve the same
  HTML to everyone, and the browser converts the displayed prices afterwards.
  Cart, checkout, order totals, order emails and the WooCommerce REST API are
  still converted on the server.
• The currency switcher no longer reloads the page when cache compatibility is
  on; it sets the cookie, converts the prices in place and refreshes the
  mini-cart.
• Fixed: prices were converted on admin screens and in admin AJAX, which could
  write a converted price into an order line item.
• Fixed: wc/v3 REST reads now return the base currency unless the request
  asks for one, so the response no longer depends on the caller’s cookies.
• Fixed: scheduled tasks and WP-CLI no longer convert prices.
• Fixed: cart totals are recalculated when the visitor changes currency, so the
  mini-cart can no longer show an amount from the previous currency.
• Fixed: prices inside WooCommerce block themes are no longer overwritten with
  base amounts after the page has loaded.
• Fixed: a percentage fee per currency was never applied, because the admin
  screen and the sanitiser disagreed on the stored value.
• Fixed: a currency with a zero exchange rate no longer falls back to showing
  base prices as though they were converted.
• Fixed: rounding is now applied to shipping, fees and coupon discounts as well
  as product prices.
• Fixed: shipping tax is converted along with the shipping amount.
• The plugin now warns in the admin when cache compatibility is silently not
  being applied, and when a mini-cart is left in the base currency because
  WooCommerce’s cart-fragment script is not loaded.
• New public REST endpoint POST mhmcs/v1/convert, rate limited to 120
  requests a minute per address (mhmcs_convert_rate_limit filter).
• See “Known limits” above for the accepted trade-offs of cache mode.

1.0.0

• First public release.
• All features are available to everyone: unlimited currencies, automatic
  exchange rate updates, geolocation-based currency detection, fixed
  per-product prices, and a WooCommerce REST API currency filter.
• Identifiers renamed to the mhmcs prefix. Settings from earlier
  development builds are not carried over.