🇨🇭 SNB — Swiss National Bank
| Property | Value |
|---|---|
| Code | SNB |
| Base Currency | CHF |
| API Endpoint | https://data.snb.ch/api/cube |
| API Format | JSON — /devkum/dimensions/en (currency list), /devkum/data/json/en (rates) |
| API Key | Not required |
| Currencies | ~25, read from the dataset's dimensions at first use (e.g. USD, EUR, GBP, JPY, CNY, AUD, CAD, …) |
| Dataset | devkum — monthly averages (M0); month-end values (M1) are not used |
| Update Frequency | Monthly, published around the 2nd business day of the following month |
| API Docs | SNB Data Portal — devkum |
⚙️ How It Works
The Swiss National Bank provides exchange rates through their Data Portal API. The SNB offers no daily-rate API: the devkum dataset holds monthly averages, and the provider stores each one on the 1st of its month to fit the daily-rate storage model.
- Currency map: loaded once per process from the
dimensionsendpoint (class-level cache). Forward rates (USD3M,USD6M) and the SDR (XDR1) are skipped. If the call fails, the provider raisesFXServiceError("Cannot load SNB currency list"). - Request: the filtered JSON endpoint with
dimSel=D0(M0),D1(…)— only monthly averages, only the requested currencies — andfromDate/toDateinYYYY-MM. - Quotation: "X CHF per 1 (or 100) units of the foreign currency". The provider divides by the unit count and returns CHF per 1 unit; the FX service normalizes the direction for storage.
🔢 Multi-Unit Currency Handling
Each series id carries its unit count: EUR1 is CHF per 1 EUR, CNY100 is CHF per 100 CNY. The provider parses it (CNY100 → CNY, 100) and divides the value by it, so a CNY100 value of 12.5 becomes 0.125 CHF per CNY.
⚠️ Limitations
- One value per month, dated the 1st: no daily movement.
- In chain routes,
compute_chain_rateneeds a rate on the exact same date for every leg, so a chain through SNB yields rates only on the 1st of each month. The provider'swarning_i18nsurfaces this as ⚠️ on such routes. - Multi-unit quotation requires special handling (automated by the provider).