UniRate Currency Converter — Open WebUI Tool

A single-file Open WebUI Tool that gives your local LLM live currency exchange rates, currency conversion, and VAT rates via the free UniRate API.

Zero third-party dependencies. The tool is written against the Python standard library only (urllib, json, asyncio). It declares no requirements:, so installing it pulls nothing from PyPI. pydantic (used only for the Valves config UI) is provided by the Open WebUI runtime, with a stdlib fallback if it is ever missing.

What the model can do

Once installed and enabled for a model, the assistant can call:

Tool function	What it does
get_exchange_rate(from_currency, to_currency)	Current rate between two currencies
convert_currency(amount, from_currency, to_currency)	Convert an amount at the current rate
list_supported_currencies()	List every supported currency code
get_vat_rate(country_code)	A country's VAT rate (ISO 3166-1 alpha-2)

Example prompts:

• "What's the EUR to USD rate right now?"
• "Convert 250 CAD to Japanese yen."
• "Which currencies does the converter support?"
• "What's the VAT rate in Germany?"

Install

1. Get a free API key at https://unirateapi.com.
2. In Open WebUI, go to Workspace → Tools → Import/Create, paste the contents of unirate_converter.py, and save. (Or install it from the Open WebUI community site.)
3. Open the tool's Valves and set api_key. Optionally set a per-user key in UserValves.
4. Enable the tool on any model that supports tool/function calling.

Configuration (Valves)

Valve	Default	Description
api_key	""	Your UniRate API key (stored as a password field)
base_url	https://api.unirateapi.com	API base URL
timeout_seconds	30	Per-request timeout

Per-user UserValves.api_key overrides the admin api_key when set.

Error handling

HTTP errors are mapped to clear, model-friendly messages rather than raised exceptions, so the assistant can relay them:

Status	Message
401	Missing or invalid API key
403	Endpoint requires a UniRate Pro subscription
404	Currency not found or no data available
429	Rate limit exceeded
503	Service temporarily unavailable
network	"Could not reach the UniRate API"

Only free-tier endpoints are used (/api/rates, /api/convert, /api/currencies, /api/vat/rates). Historical/time-series endpoints are Pro-gated and intentionally not exposed by this tool.

Testing

# Mock suite — stdlib only, no network, no pytest:
python test_unirate_tool.py

# Live free-tier suite (self-skips without a key):
UNIRATE_API_KEY=your-key python test_live.py

Related UniRate clients

Full client libraries in 20+ languages and framework integrations: https://github.com/UniRate-API

License

MIT © 2026 Unirate Team