diff --git a/.gitea/workflows/python-package.yml b/.gitea/workflows/python-package.yml
new file mode 100644
index 0000000..f0512f8
--- /dev/null
+++ b/.gitea/workflows/python-package.yml
@@ -0,0 +1,14 @@
+name: Test and Package Python
+on: [push]
+
+jobs:
+  Test:
+    uses: jmaa/workflows/.gitea/workflows/python-test.yaml@v6.21
+  Package:
+    uses: jmaa/workflows/.gitea/workflows/python-package.yaml@v6.21
+    with:
+      REGISTRY_DOMAIN: gitfub.space
+      REGISTRY_ORGANIZATION: usagi-keiretsu
+    secrets:
+      PIPY_REPO_USER: ${{ secrets.PIPY_REPO_USER }}
+      PIPY_REPO_PASS: ${{ secrets.PIPY_REPO_PASS }}
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..e6e989c
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,18 @@
+# Program specific
+/output/
+/deps/
+/secrets/
+/private_deps/
+/data/
+
+# Python
+__pycache__/
+/build/
+/dist/
+*.egg-info/
+
+# Python, Testing
+/test/secrets.py
+/.coverage
+/.hypothesis/
+/htmlcov/
diff --git a/fin_defs/__init__.py b/fin_defs/__init__.py
new file mode 100644
index 0000000..bf65ad7
--- /dev/null
+++ b/fin_defs/__init__.py
@@ -0,0 +1,412 @@
+import abc
+import dataclasses
+import datetime
+import re
+from collections.abc import Iterator
+from decimal import Decimal
+
+import enforce_typing
+
+## Ids
+
+RE_TICKER_FORMAT = r'^[A-Z0-9_]+$'
+RE_TICKER_FORMAT_FLEXIBLE = r'^[^:\s]+$'
+RE_CRYPTO_TICKER_FORMAT = r'^\S+$'
+
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True)
+class StockExchange:
+    """Unified Stock Exchange identifiers."""
+
+    name: str
+    mic: str
+    bloomberg_id: str | None = None
+    crunchbase_id: str | None = None
+    yahoo_id: str | None = None
+    eod_id: str | None = None
+
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True)
+class Asset:
+
+    def names(self) -> list[str]:
+        return COMMON_NAMES.get(self, [])
+
+    def to_polygon_id(self) -> str:
+        # TODO: Support currency pairs not involving USD.
+        if isinstance(self, Stock):
+            return f'{self.ticker}'
+        if isinstance(self, Index):
+            return f'I:{self.ticker}'
+        if isinstance(self, FiatCurrency):
+            return f'C:{self.iso_code}USD'
+        if isinstance(self, CryptoCurrency):
+            return f'X:{self.ccxt_symbol}USD'
+
+        # Else
+        msg = f'Unknown self type: {self}'
+        raise Exception(msg)
+
+    @staticmethod
+    def from_polygon_id(polygon_id: str) -> 'Asset':
+        if polygon_id.startswith('I:'):
+            return Index(polygon_id.removeprefix('I:'))
+        if polygon_id.startswith('X:'):
+            return CryptoCurrency(
+                polygon_id.removeprefix('X:').removesuffix('USD'),
+                None,
+            )
+        if polygon_id.startswith('C:'):
+            return FiatCurrency(polygon_id.removeprefix('C:').removesuffix('USD'))
+        return Stock.from_polygon_id(polygon_id)
+
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True)
+class Currency(Asset):
+    pass
+
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True, eq=True, order=True)
+class FiatCurrency(Currency):
+    iso_code: str
+
+    def __post_init__(self):
+        if not re.match(RE_TICKER_FORMAT, self.iso_code):
+            msg = f'iso_code was not in correct format: {self.iso_code}'
+            raise ValueError(msg)
+
+    def __str__(self):
+        return self.iso_code
+
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True, eq=True)
+class CryptoCurrency(Currency):
+    ccxt_symbol: str
+    coingecko_id: str | None
+
+    def __post_init__(self):
+        '''TODO
+        if not re.match(RE_CRYPTO_TICKER_FORMAT, self.ccxt_symbol):
+            msg = f'ccxt_symbol was not in correct format: {self.ccxt_symbol}'
+            raise ValueError(msg)
+        '''
+
+    def __str__(self):
+        return self.ccxt_symbol
+
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True, eq=True)
+class Stock(Asset):
+    ticker: str
+    exchange: StockExchange
+
+    def __post_init__(self):
+        if not re.match(RE_TICKER_FORMAT_FLEXIBLE, self.ticker):
+            msg = f'ticker was not in correct format: {self.ticker}'
+            raise ValueError(msg)
+
+    def __str__(self):
+        return f'{self.ticker}.{self.exchange.mic}'
+
+    @staticmethod
+    def from_polygon_id(polygon_id: str, stock_exchange: StockExchange) -> 'Stock':
+        return Stock(polygon_id, stock_exchange)
+
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True, eq=True)
+class Index(Asset):
+    ticker: str
+
+    def __post_init__(self):
+        if not re.match(RE_TICKER_FORMAT_FLEXIBLE, self.ticker):
+            msg = f'ticker was not in correct format: {self.ticker}'
+            raise ValueError(msg)
+
+    def __str__(self):
+        return self.ticker
+
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True, eq=True)
+class Commodity(Asset):
+    alpha_vantage_id: str
+
+    def __post_init__(self):
+        if not re.match(RE_TICKER_FORMAT, self.alpha_vantage_id):
+            msg = f'alpha_vantage_id was not in correct format: {self.alpha_vantage_id}'
+            raise ValueError(msg)
+
+    def __str__(self):
+        return self.alpha_vantage_id
+
+
+Commodity.CRUDE_OIL_WTI = Commodity('WTI')
+Commodity.CRUDE_OIL_BRENT = Commodity('BRENT')
+Commodity.NATURAL_GAS = Commodity('NATURAL_GAS')
+Commodity.COPPER = Commodity('COPPER')
+Commodity.WHEAT = Commodity('WHEAT')
+Commodity.CORN = Commodity('CORN')
+Commodity.COTTON = Commodity('COTTON')
+Commodity.SUGAR = Commodity('SUGAR')
+Commodity.COFFEE = Commodity('COFFEE')
+
+# Well known
+
+DKK = FiatCurrency('DKK')
+USD = FiatCurrency('USD')
+EUR = FiatCurrency('EUR')
+BTC = CryptoCurrency('BTC', coingecko_id='bitcoin')
+MPC = CryptoCurrency('MPC', coingecko_id='partisia-blockchain')
+SPX = Index('SPX')
+NDX = Index('NDX')
+
+COMMON_NAMES: dict[Asset, list[str]] = {
+    FiatCurrency('USD'): ['U.S. Dollar'],
+    FiatCurrency('DKK'): ['Danske Kroner', 'Danish Crowns'],
+    FiatCurrency('EUR'): ['Euro'],
+    FiatCurrency('JPY'): ['Japanese Yen'],
+    FiatCurrency('CAD'): ['Canadian Dollar'],
+    FiatCurrency('GBP'): ['British Pound'],
+    FiatCurrency('CNY'): ['Renminbi'],
+    FiatCurrency('PLN'): ['Polish Zloty'],
+    FiatCurrency('ILS'): ['Israeli new Shekel'],
+    FiatCurrency('CHF'): ['Swiss Franc'],
+    FiatCurrency('ZAR'): ['South African Rand'],
+    FiatCurrency('CZK'): ['Czech Koruna'],
+    SPX: ['Standard and Poor 500', 'S&P 500'],
+    NDX: ['Nasdaq 100'],
+    BTC: ['Bitcoin BTC'],
+    MPC: ['Partisia Blockchain MPC Token'],
+    CryptoCurrency('ETH', 'ethereum'): ['Ethereum Ether'],
+    CryptoCurrency('DOGE', 'dogecoin'): ['Dogecoin'],
+    CryptoCurrency('SOL', 'solana'): ['Solana SOL'],
+    CryptoCurrency('ADA', 'cardano'): ['Cardano ADA'],
+    CryptoCurrency('BNB', 'bnb'): ['Binance BNB'],
+    CryptoCurrency('MATIC', 'polygon'): ['Polygon MATIC'],
+    # Stable-coins
+    CryptoCurrency('DAI', 'dai'): ['DAI'],
+    CryptoCurrency('USDC', 'usdc'): ['USD Coin'],
+    CryptoCurrency('USDT', 'tether'): ['Tether USDT'],
+}
+
+WELL_KNOWN_SYMBOLS = (
+    {
+        sym: FiatCurrency(sym)
+        for sym in [
+            'USD',
+            'DKK',
+            'EUR',
+            'JPY',
+            'CAD',
+            'GBP',
+            'CNY',
+            'PLN',
+            'ILS',
+            'CHF',
+            'ZAR',
+            'CZK',
+        ]
+    }
+    | {str(k): k for k in COMMON_NAMES}
+    | {'SPX500': SPX, 'SP500': SPX, 'Nasdaq 100': NDX}
+)
+
+NYSE = StockExchange(
+    name='New York Stock Exchange',
+    mic='XNYS',
+    bloomberg_id='UN',
+    crunchbase_id='NYSE',
+)
+
+EXCHANGES = [
+    NYSE,
+    StockExchange(name='Nasdaq', mic='XNAS', bloomberg_id='US', crunchbase_id='NASDAQ'),
+    StockExchange(
+        name='Hong Kong Exchanges And Clearing',
+        mic='XHKG',
+        bloomberg_id='HK',
+        crunchbase_id='SEHK',
+    ),
+    StockExchange(
+        name='Moscow Exchange',
+        mic='MISC',
+        bloomberg_id='RX',
+        yahoo_id='ME',
+        eod_id='MCX',
+        crunchbase_id='MOEX',
+    ),
+    StockExchange(name='Shanghai Stock Exchange', mic='XSHG'),
+    StockExchange(name='Euronext Amsterdam', mic='XAMS'),
+    StockExchange(name='Euronext Brussels', mic='XBRU'),
+    StockExchange(name='Euronext Dublin', mic='XMSM'),
+    StockExchange(name='Euronext Lisbon', mic='XLIS'),
+    StockExchange(name='Euronext Milan', mic='XMIL'),
+    StockExchange(name='Euronext Oslo', mic='XOSL'),
+    StockExchange(name='Euronext Paris', mic='XPAR'),
+    StockExchange(name='Japan Exchange Group', mic='XJPX'),
+    StockExchange(name='Shenzhen Stock Exchange', mic='XSHE'),
+    StockExchange(name='Indian National Stock Exchange', mic='XNSE'),
+    StockExchange(
+        name='Bombay Stock Exchange',
+        mic='XBOM',
+        bloomberg_id='IB',
+        crunchbase_id='BOM',
+        yahoo_id='BO',
+    ),
+    StockExchange(name='Toronto Stock Exchange', mic='XTSE'),
+    StockExchange(name='London Stock Exchange', mic='XLON'),
+    StockExchange(name='Saudi Stock Exchange', mic='XSAU'),
+    StockExchange(name='German Stock Exchange', mic='XFRA'),
+    StockExchange(name='SIX Swiss Exchange', mic='XSWX'),
+    StockExchange(name='Nasdaq Copenhagen Stock Exchange', mic='XCSE'),
+    StockExchange(name='Nasdaq Stockholm Stock Exchange', mic='XSTO'),
+    StockExchange(name='Nasdaq Helsinki Stock Exchange', mic='XHEL'),
+    StockExchange(name='Nasdaq Tallinn Stock Exchange', mic='XTAL'),
+    StockExchange(name='Nasdaq Riga Stock Exchange', mic='XRIS'),
+    StockExchange(name='Nasdaq Vilnius Stock Exchange', mic='XLIT'),
+    StockExchange(name='Nasdaq Iceland Stock Exchange', mic='XICE'),
+    StockExchange(name='Korea Exchange', mic='XKOS'),
+    StockExchange(name='Taiwan Stock Exchange', mic='XTAI'),
+    StockExchange(name='Australian Securities Exchange', mic='XASX'),
+    StockExchange(name='Johannesburg Stock Exchange', mic='XJSE'),
+    StockExchange(name='Tehran Stock Exchange', mic='XTEH'),
+]
+
+EXCHANGES_BY_IDS = {}
+if True:
+
+    def add_by_id(exchange: StockExchange, key: str):
+        exchange_id = getattr(exchange, key)
+        if exchange_id is not None:
+            if exchange_id in EXCHANGES_BY_IDS:
+                msg = f'Exchange {exchange_id} is already present'
+                raise ValueError(msg)
+            EXCHANGES_BY_IDS[exchange_id] = exchange
+
+    for exchange in EXCHANGES:
+        add_by_id(exchange, 'mic')
+        add_by_id(exchange, 'bloomberg_id')
+        add_by_id(exchange, 'crunchbase_id')
+        add_by_id(exchange, 'yahoo_id')
+        add_by_id(exchange, 'eod_id')
+        del exchange
+    del add_by_id
+
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True, slots=True)
+class AssetInformation:
+    """Extensive information about a given asset."""
+
+    asset: Asset
+    full_name: str
+    description: str | None = None
+    asset_base: Asset | None = None
+    sec_cik: str | None = None
+    # TODO: FIGI types? (https://www.openfigi.com/)
+
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True, eq=True, slots=True)
+class AssetAmount:
+    """Decimal with associated asset unit."""
+
+    asset: Asset
+    amount: Decimal
+
+    def __str__(self):
+        specificity = '2' if self.amount >= 0.10 else '3'
+        return ('{:.' + specificity + 'f} {}').format(self.amount, self.asset)
+
+    def __mul__(self, other: Decimal):
+        if not isinstance(other, Decimal):
+            msg = f'other must be decimal, but was {type(other)}'
+            raise TypeError(msg)
+        return AssetAmount(self.asset, self.amount * other)
+
+    def __add__(self, other):
+        if not isinstance(other, AssetAmount):
+            msg = f'other must be AssetAmount, but was {type(other)}'
+            raise TypeError(msg)
+        if self.asset != other.asset:
+            msg = (
+                f'AssetAmount must have same asset, but: {self.asset} != {other.asset}'
+            )
+            raise ValueError(msg)
+
+        return AssetAmount(self.asset, self.amount + other.amount)
+
+    def __sub__(self, other):
+        if not isinstance(other, AssetAmount):
+            msg = f'other must be AssetAmount, but was {type(other)}'
+            raise TypeError(msg)
+        if self.asset != other.asset:
+            msg = (
+                f'AssetAmount must have same asset, but: {self.asset} != {other.asset}'
+            )
+            raise ValueError(msg)
+        return AssetAmount(self.asset, self.amount - other.amount)
+
+    def __truediv__(self, other):
+        if isinstance(other, AssetAmount):
+            if self.asset != other.asset:
+                msg = f'AssetAmount must have same asset, but: {self.asset} != {other.asset}'
+                raise ValueError(msg)
+            return self.amount / other.amount
+        return AssetAmount(self.asset, self.amount / other)
+
+    def __lt__(self, other):
+        if not isinstance(other, AssetAmount):
+            msg = f'other must be AssetAmount, but was {type(other)}'
+            raise TypeError(msg)
+        if self.asset != other.asset:
+            msg = (
+                f'AssetAmount must have same asset, but: {self.asset} != {other.asset}'
+            )
+            raise ValueError(msg)
+        return self.amount < other.amount
+
+
+@dataclasses.dataclass(frozen=True, eq=True)
+class ExchangeRateSample(Asset):
+    """Single exchange rate sample with a timestamp and various stats."""
+
+    timestamp: datetime.date | datetime.datetime
+    _average: Decimal | None = None
+    last: Decimal | None = None
+    open: Decimal | None = None
+    close: Decimal | None = None
+    high: Decimal | None = None
+    low: Decimal | None = None
+    volume: Decimal | None = None
+    market_cap: Decimal | None = None
+
+    @property
+    def average(self) -> Decimal:
+        if self._average:
+            return self._average
+        return (self.high + self.low) / 2
+
+    def replace_timestamp(self, timestamp):
+        return dataclasses.replace(self, timestamp=timestamp)
+
+    def invert_exchange_rate(self):
+        one = Decimal('1')
+        return dataclasses.replace(
+            self,
+            _average=one / self._average if self._average else None,
+            last=one / self.last if self.last else None,
+            open=one / self.open if self.open else None,
+            close=one / self.close if self.close else None,
+            high=one / self.low if self.low else None,
+            low=one / self.high if self.high else None,
+            # TODO: Support volume
+            # TODO: Support market_cap
+        )
diff --git a/fin_defs/_version.py b/fin_defs/_version.py
new file mode 100644
index 0000000..850505a
--- /dev/null
+++ b/fin_defs/_version.py
@@ -0,0 +1 @@
+__version__ = '0.1.10'
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..63a601e
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+enforce-typing
diff --git a/requirements_test.txt b/requirements_test.txt
new file mode 100644
index 0000000..e079f8a
--- /dev/null
+++ b/requirements_test.txt
@@ -0,0 +1 @@
+pytest
diff --git a/setup.py b/setup.py
new file mode 100644
index 0000000..091c8a2
--- /dev/null
+++ b/setup.py
@@ -0,0 +1,68 @@
+#!/usr/bin/env python
+#
+# WARNING
+#
+# THIS IS AN AUTOGENERATED FILE.
+#
+# MANUAL CHANGES CAN AND WILL BE OVERWRITTEN.
+
+import re
+
+from setuptools import setup
+
+PACKAGE_NAME = 'fin_defs'
+
+with open('README.md') as f:
+    readme = f.read()
+
+with open(PACKAGE_NAME + '/_version.py') as f:
+    text = f.read()
+    match = re.match(r'^__version__\s*=\s*(["\'])([\d\.]+)\1$', text)
+    version = match.group(2)
+    del match, text
+
+
+def parse_requirements(text: str) -> list[str]:
+    return text.strip().split('\n')
+
+
+def read_requirements(path: str):
+    with open(path) as f:
+        return parse_requirements(f.read())
+
+
+def get_short_description(readme: str):
+    readme = re.sub(r'#+[^\n]*\n+', '', readme)
+    m = re.search(r'^\s*(\w+[\w\s,`-]+\.)', readme)
+    try:
+        return m.group(1)
+    except AttributeError as err:
+        msg = 'Could not determine short description'
+        raise Exception(msg) from err
+
+
+REQUIREMENTS_MAIN = """
+enforce-typing
+"""
+
+REQUIREMENTS_TEST = """
+pytest
+"""
+
+
+setup(
+    name=PACKAGE_NAME,
+    version=version,
+    description=get_short_description(readme),
+    long_description=readme,
+    long_description_content_type='text/markdown',
+    author='Jmaa',
+    author_email='jonjmaa@gmail.com',
+    url='https://gitfub.space/Jmaa/' + PACKAGE_NAME,
+    packages=[PACKAGE_NAME],
+    install_requires=parse_requirements(REQUIREMENTS_MAIN),
+    extras_require={
+        'test': parse_requirements(REQUIREMENTS_TEST),
+    },
+    python_requires='>=3.9',
+)
diff --git a/test/__init__.py b/test/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/test/test_data.py b/test/test_data.py
new file mode 100644
index 0000000..055c933
--- /dev/null
+++ b/test/test_data.py
@@ -0,0 +1,23 @@
+import pytest
+
+import fin_defs
+
+BAD_TICKERS = ['TEST123', '123', 'TEST.EUR', 'TEST:EUR', 'EUR:TEST']
+
+
+@pytest.mark.parametrize('ticker', BAD_TICKERS)
+def test_bad_tickers(ticker):
+    try:
+        fin_defs.Stock(ticker)
+    except Exception as e:
+        assert e
+
+
+@pytest.mark.parametrize('ticker', BAD_TICKERS)
+def test_crypto_tickers(ticker):
+    fin_defs.CryptoCurrency(ticker, 'not-known')
+
+
+def test_str():
+    NVO = fin_defs.Stock('NVO', fin_defs.EXCHANGES_BY_IDS['NYSE'])
+    assert str(NVO) == 'NVO.XNYS'