--- title: "CNB CZK Exchange Rates" description: "Daily Czech National Bank (ČNB) CZK fixing rates for 30 currencies as TapHome sensors, via the public CNB API with no API key, refreshed hourly." url: "https://taphome.com/en/compatibility/cnb-czk/" language: en lastmod: 2026-10-08 generator: hugo ai: topics: ["http","data-service","exchange-rates","currency","cloud-api","packet-parser"] questions: ["How to integrate CNB exchange rates with TapHome?","What currencies does the CNB CZK exchange rate template support?","How to automate actions based on currency exchange rates in TapHome?","How often are CNB exchange rates updated?","How to track EUR/CZK or USD/CZK rate in TapHome?"] --- # CNB CZK Exchange Rates Communication: Packet Parser → HTTP - [Czech National Bank](https://www.cnb.cz/en/) ## Integration guide The Czech National Bank (CNB) publishes official CZK exchange rates daily for 30 foreign currencies. These rates are the official fixing rates used as a reference across the Czech financial system. The TapHome template fetches all 30 exchange rates from the public CNB REST API (`api.cnb.cz`) via HTTP Packet Parser. Each currency is exposed as a separate read-only sensor showing its current CZK rate. The API is completely public — no authentication, API key, or registration is required. TapHome fetches the rates once per hour; CNB publishes new rates once per working day around 14:30. ## Configuration The template connects to `api.cnb.cz` over HTTPS (port 443). No IP address, credentials, or API key are needed — the endpoint is a fully public government API. There are no user-configurable variables. The only custom variable (`responsejson`) is an internal HTTP response cache used by the template scripts — it does not need to be modified. ## How it works The module sends a single HTTP GET request once per hour (3,600,000 ms polling interval): ``` GET /cnbapi/exrates/daily?date={today}&lang=CZ ``` The response is a JSON object containing a `rates[]` array with all 30 currency entries. Each entry includes the currency code, country name, amount, and rate. The module stores the full JSON response in the `responsejson` variable. Each currency device then parses its rate from the cached response using `PARSEJSON(responsejson, "$.rates[N].rate")`, where N is the fixed array index for that currency. The device poll interval is 15 seconds, but since all devices read from the cached `responsejson`, no additional API calls are made between hourly refreshes. > [!NOTE] > The template uses `lang=CZ` in the API request. This is critical because the `rates[]` array is sorted alphabetically by country name in the selected language. Changing to `lang=EN` would produce a different sort order and break all array index mappings. ## Device capabilities The template provides 30 read-only sensor devices, one for each currency. All values are in CZK. ### Major currencies The most commonly tracked rates include EUR (Euro), USD (US Dollar), GBP (British Pound), CHF (Swiss Franc), and PLN (Polish Zloty). These are quoted per 1 unit of foreign currency — for example, a USD rate of 21.315 means 1 USD = 21.315 CZK. ### Multi-unit currencies Nine currencies use multi-unit rates due to their low per-unit CZK value: | Currency | Amount | Meaning | |----------|--------|---------| | HUF (Hungarian Forint) | 100 | Rate per 100 HUF | | INR (Indian Rupee) | 100 | Rate per 100 INR | | ISK (Icelandic Krona) | 100 | Rate per 100 ISK | | JPY (Japanese Yen) | 100 | Rate per 100 JPY | | KRW (South Korean Won) | 100 | Rate per 100 KRW | | PHP (Philippine Peso) | 100 | Rate per 100 PHP | | THB (Thai Baht) | 100 | Rate per 100 THB | | TRY (Turkish Lira) | 100 | Rate per 100 TRY | | IDR (Indonesian Rupiah) | 1000 | Rate per 1000 IDR | The template reads the raw `rate` value from the API without dividing by the `amount`. For example, a JPY rate of 13.328 in TapHome means 100 JPY = 13.328 CZK, not 1 JPY = 13.328 CZK. ### Complete currency list All 30 currencies: AUD, BRL, CAD, CHF, CNY, DKK, EUR, GBP, HKD, HUF, IDR, ILS, INR, ISK, JPY, KRW, MXN, MYR, NOK, NZD, PHP, PLN, RON, SEK, SGD, THB, TRY, USD, XDR (IMF Special Drawing Rights), ZAR. ## Automation examples ### Notify on rate threshold Use a currency sensor in a smart rule condition to receive notifications when a rate crosses a threshold: - Condition: EUR value crosses above 25.00 - Action: Send push notification ### Rate-based switching Trigger actions based on exchange rate movements — for example, switch display indicators or control outputs when a monitored currency reaches a target range. ## Troubleshooting ### All devices show zero or no data 1. Check internet connectivity on TapHome Core — the template requires outbound HTTPS access to `api.cnb.cz` 2. Verify the API is responding — open `https://api.cnb.cz/cnbapi/exrates/daily?date=2026-03-28&lang=CZ` in a browser 3. New exchange rates are published every working day around 14:30 CET. On weekends and holidays, the API returns the last valid rates ### Values seem incorrect for some currencies Check the multi-unit rates table above. Currencies like JPY, HUF, KRW, and IDR are quoted per 100 or 1000 units, not per 1 unit. This is the standard CNB convention, not a template error. ### Data stops updating The template polls the API once per hour. If rates appear stale, verify that TapHome Core has internet access and that the CNB API is reachable. The API has no documented rate limits, but prolonged connectivity issues will prevent updates. ## Available devices 30 These devices appear in TapHome after import. CNB CZK Exchange Rates Module Custom Variables Read (module) ```taphome VAR today := tostring(NOW(), "yyyy-MM-dd"); VAR response := SENDHTTPREQUEST("/cnbapi/exrates/daily?date=" + today + "&lang=CZ"); IF response.IsSuccess responsejson := response.Content; ELSE ADDERROR(response.StatusCode + " (" + response.ReasonPhrase + ")"); END ``` Australian Dollar (AUD) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[0].rate"); ``` Brazilian Real (BRL) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[1].rate"); ``` Canadian Dollar (CAD) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[13].rate"); ``` Chinese Renminbi (CNY) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[2].rate"); ``` Danish Krone (DKK) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[3].rate"); ``` Euro (EUR) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[4].rate"); ``` British Pound (GBP) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[29].rate"); ``` Hong Kong Dollar (HKD) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[6].rate"); ``` Hungarian Forint (HUF) Variable Read-only Rate per 100 HUF string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[15].rate"); ``` Swiss Franc (CHF) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[25].rate"); ``` Indonesian Rupiah (IDR) Variable Read-only Rate per 1000 IDR string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[8].rate"); ``` Israeli Shekel (ILS) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[10].rate"); ``` Indian Rupee (INR) Variable Read-only Rate per 100 INR string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[7].rate"); ``` Icelandic Krona (ISK) Variable Read-only Rate per 100 ISK string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[9].rate"); ``` Japanese Yen (JPY) Variable Read-only Rate per 100 JPY string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[11].rate"); ``` South Korean Won (KRW) Variable Read-only Rate per 100 KRW string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[14].rate"); ``` Mexican Peso (MXN) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[17].rate"); ``` Malaysian Ringgit (MYR) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[16].rate"); ``` Norwegian Krone (NOK) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[19].rate"); ``` New Zealand Dollar (NZD) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[20].rate"); ``` Philippine Peso (PHP) Variable Read-only Rate per 100 PHP string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[5].rate"); ``` Polish Zloty (PLN) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[21].rate"); ``` Romanian Leu (RON) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[22].rate"); ``` Swedish Krona (SEK) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[24].rate"); ``` Singapore Dollar (SGD) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[23].rate"); ``` Thai Baht (THB) Variable Read-only Rate per 100 THB string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[26].rate"); ``` Turkish Lira (TRY) Variable Read-only Rate per 100 TRY string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[27].rate"); ``` US Dollar (USD) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[28].rate"); ``` IMF SDR (XDR) Variable Read-only IMF Special Drawing Rights — composite reserve asset string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[18].rate"); ``` South African Rand (ZAR) Variable Read-only string Unit: CZK json\_path Read ```taphome PARSEJSON(responsejson, "$.rates[12].rate"); ``` **Connection:** Packet Parser → HTTP ## Sources - CNB API — OpenAPI Specification [api.cnb.cz](https://api.cnb.cz/cnbapi/api-docs) 2026-03-28 - CNB Exchange Rate Format & Currency List [www.cnb.cz](https://www.cnb.cz/en/faq/Format-of-the-foreign-exchange-market-rates/) 2026-03-28 ## Related Documentation - [Packet Parser Integration](https://taphome.com/en/compatibility/packet-parser-guide/) - [Packet Parser (HTTP, TCP, UDP, FTP, MQTT)](https://taphome.com/en/docs/integration/packet-parser/) - [Packet parser functions](https://taphome.com/en/docs/script/packet-parser/) - [Parsing functions](https://taphome.com/en/docs/script/parsing-functions/)