flask-unirate

Flask extension for the UniRate currency-exchange API:

• Drop-in UniRate(app) extension — follows the standard init_app factory pattern, registers itself on app.extensions["unirate"].
• Jinja filters — {{ amount|to_currency('EUR') }}, {{ amount|convert_currency('USD', 'JPY') }}, {{ price|format_money('USD') }}, plus to_usd / to_eur / to_gbp shortcuts.
• Optional Flask-Caching integration — set UNIRATE_CACHE_TIMEOUT and the extension caches latest-rate / supported-currency lookups through whatever Flask-Caching backend you already have.
• Wraps the official unirate-api Python client; full method surface is reachable through unirate.client if you need historical rates / VAT / time series.

UniRate covers 593+ fiat, crypto, and commodity codes. Latest rates and conversion are on the free tier; historical endpoints (get_historical_rate, convert_historical) require Pro.

Install

pip install flask-unirate

With Flask-Caching support:

pip install "flask-unirate[caching]"

Quick start

import os

from flask import Flask, render_template_string

from flask_unirate import UniRate

app = Flask(__name__)
app.config["UNIRATE_API_KEY"] = os.environ["UNIRATE_API_KEY"]
unirate = UniRate(app)


@app.route("/rate/<base>/<quote>")
def rate(base: str, quote: str):
    return {"rate": unirate.get_rate(base, quote)}


@app.route("/checkout/<int:amount_usd>")
def checkout(amount_usd: int):
    return render_template_string(
        """
        <p>USD: {{ amount|format_money('USD') }}</p>
        <p>EUR: {{ amount|to_eur|format_money('EUR') }}</p>
        <p>JPY: {{ amount|to_currency('JPY')|format_money('JPY', decimals=0) }}</p>
        """,
        amount=amount_usd,
    )

Configuration

Factory pattern

from flask import Flask
from flask_unirate import UniRate

unirate = UniRate()


def create_app() -> Flask:
    app = Flask(__name__)
    app.config.from_pyfile("config.py")
    unirate.init_app(app)
    return app

Inside any view (or template) you can also reach the extension through current_app:

from flask import current_app

current_app.extensions["unirate"].get_rate("USD", "EUR")

…or through the convenience helper:

from flask_unirate import get_unirate

get_unirate().get_rate("USD", "EUR")

Jinja filters

Every filter is registered automatically when you call UniRate(app) / init_app(app):

Chain them: {{ amount|to_eur|format_money('EUR') }}.

Flask-Caching integration

from flask import Flask
from flask_caching import Cache

from flask_unirate import UniRate

app = Flask(__name__)
app.config.update(
    UNIRATE_API_KEY="...",
    UNIRATE_CACHE_TIMEOUT=300,         # 5 minutes
    CACHE_TYPE="RedisCache",
    CACHE_REDIS_URL="redis://localhost",
)
Cache(app)
UniRate(app)

The extension auto-discovers the Cache instance off app.extensions['cache'] — so all of Flask-Caching's backends (SimpleCache, RedisCache, MemcachedCache, FileSystemCache, …) work with no extra wiring. Failures fall through to a fresh API call rather than raising.

Errors

Errors come from the underlying unirate-api client and propagate unchanged:

Wrap the call site in try / except UnirateError to catch the whole family.

Compatibility

• Python 3.9 – 3.13
• Flask ≥ 2.0
• unirate-api ≥ 1.0
• (Optional) flask-caching ≥ 2.0

Related

• unirate-api — base sync Python client (this package wraps it).
• fastapi-unirate — async sibling for FastAPI.
• langchain-unirate — LangChain partner package.
• Other UniRate integrations: dbt, Airflow, n8n, Raycast, MCP server. Full list at https://unirateapi.com.

License

MIT