feat: EXAA client for Austrian day-ahead prices

.env.example

@@ -6,3 +6,10 @@ NORDPOOL_PASSWORD=
 # ENTSO-E Transparency Platform security token
 # Obtain from: https://transparency.entsoe.eu/usrm/user/myAccountSettings
 ENTSOE_API_KEY=
+
+# EXAA (Energy Exchange Austria) — certificate-based authentication
+# Register at: https://www.exaa.at/en/trading/registration
+EXAA_USERNAME=
+EXAA_PASSWORD=
+EXAA_PRIVATE_KEY_PATH=/path/to/exaa_private_key.pem
+EXAA_CERTIFICATE_PATH=/path/to/exaa_certificate.pem

README.md

@@ -27,6 +27,7 @@ Handles 15-minute MTU resolution, rate limiting, response caching, timezone norm
 | Core types & exceptions | ✅ |
 | Unified `NexaClient` | 🚧 |
 | ENTSO-E client | ✅ |
+| EXAA client (AT day-ahead) | ✅ |
 | EPEX SPOT client | ⬜ |
 | EEX client | ⬜ |
 | Response caching | ⬜ |
@@ -71,6 +72,10 @@ Set API credentials as environment variables:
 export NORDPOOL_USERNAME="your-username"
 export NORDPOOL_PASSWORD="your-password"
 export ENTSOE_API_KEY="your-key-here"
+export EXAA_USERNAME="your-exaa-username"
+export EXAA_PASSWORD="your-exaa-password"
+export EXAA_PRIVATE_KEY_PATH="/path/to/exaa_private_key.pem"
+export EXAA_CERTIFICATE_PATH="/path/to/exaa_certificate.pem"
 ```
 
 Or use a `.env` file (see `.env.example`).

pyproject.toml

@@ -28,6 +28,7 @@ pydantic = ">=2.0"
 pandas = ">=2.0"
 tenacity = ">=8.0"
 entsoe-py = ">=0.6"
+nexa-connect-exaa = {git = "https://github.com/phasenexa/nexa-connect-exaa.git"}
 
 [tool.poetry.group.dev.dependencies]
 pytest = ">=8.0"
@@ -60,6 +61,8 @@ ignore = []
 
 [tool.ruff.lint.per-file-ignores]
 "tests/**" = ["ANN"]
+# exaa.py wraps an untyped third-party library; Any is unavoidable there.
+"src/nexa_marketdata/exaa.py" = ["ANN401"]
 
 [tool.mypy]
 python_version = "3.11"
@@ -72,6 +75,10 @@ explicit_package_bases = true
 module = ["entsoe", "entsoe.*"]
 ignore_missing_imports = true
 
+[[tool.mypy.overrides]]
+module = ["nexa_connect_exaa", "nexa_connect_exaa.*"]
+ignore_missing_imports = true
+
 [tool.pytest.ini_options]
 testpaths = ["tests"]
 addopts = "--cov=src/nexa_marketdata --cov-report=term-missing --cov-report=xml"

src/nexa_marketdata/client.py

@@ -8,6 +8,7 @@
 import pandas as pd
 
 from nexa_marketdata.entsoe import ENTSOEClient
+from nexa_marketdata.exaa import EXAAClient
 from nexa_marketdata.exceptions import DataNotAvailableError
 from nexa_marketdata.nordpool import NordPoolClient
 from nexa_marketdata.types import BiddingZone, Resolution
@@ -28,7 +29,6 @@
         BiddingZone.DK2,
         BiddingZone.FI,
         BiddingZone.DE_LU,
-        BiddingZone.AT,
         BiddingZone.BE,
         BiddingZone.NL,
         BiddingZone.FR,
@@ -44,6 +44,16 @@
     }
 )
 
+# Zones served by EXAA (Energy Exchange Austria).
+# AT is EXAA's home market; the Classic auction at 10:15 CET is the
+# authoritative Austrian day-ahead price and the only source of 15-minute
+# products for AT.
+_EXAA_ZONES: frozenset[BiddingZone] = frozenset(
+    {
+        BiddingZone.AT,
+    }
+)
+
 
 class NexaClient:
     """Unified client for European power market data sources.
@@ -55,13 +65,25 @@ class NexaClient:
             ``NORDPOOL_PASSWORD`` environment variable.
         entsoe_api_key: ENTSO-E Transparency Platform security token. Falls
             back to ``ENTSOE_API_KEY`` environment variable.
+        exaa_username: EXAA trading account username. Falls back to
+            ``EXAA_USERNAME`` environment variable.
+        exaa_password: EXAA trading account password. Falls back to
+            ``EXAA_PASSWORD`` environment variable.
+        exaa_private_key_path: Path to EXAA RSA private key PEM file. Falls
+            back to ``EXAA_PRIVATE_KEY_PATH`` environment variable.
+        exaa_certificate_path: Path to EXAA X.509 certificate PEM file. Falls
+            back to ``EXAA_CERTIFICATE_PATH`` environment variable.
     """
 
     def __init__(
         self,
         nordpool_username: str | None = None,
         nordpool_password: str | None = None,
         entsoe_api_key: str | None = None,
+        exaa_username: str | None = None,
+        exaa_password: str | None = None,
+        exaa_private_key_path: str | None = None,
+        exaa_certificate_path: str | None = None,
     ) -> None:
         username = nordpool_username or os.environ.get("NORDPOOL_USERNAME")
         password = nordpool_password or os.environ.get("NORDPOOL_PASSWORD")
@@ -73,6 +95,16 @@ def __init__(
             ENTSOEClient(self._entsoe_api_key) if self._entsoe_api_key else None
         )
 
+        exaa_user = exaa_username or os.environ.get("EXAA_USERNAME")
+        exaa_pass = exaa_password or os.environ.get("EXAA_PASSWORD")
+        exaa_key = exaa_private_key_path or os.environ.get("EXAA_PRIVATE_KEY_PATH")
+        exaa_cert = exaa_certificate_path or os.environ.get("EXAA_CERTIFICATE_PATH")
+        self._exaa = (
+            EXAAClient(exaa_user, exaa_pass, exaa_key, exaa_cert)
+            if (exaa_user and exaa_pass and exaa_key and exaa_cert)
+            else None
+        )
+
     def day_ahead_prices(
         self,
         zone: BiddingZone,
@@ -114,6 +146,14 @@ def day_ahead_prices(
             return self._entsoe.day_ahead_prices(
                 zone, start, end, resolution=resolution
             )
+        if zone in _EXAA_ZONES:
+            if self._exaa is None:
+                raise DataNotAvailableError(
+                    f"No EXAA credentials configured for zone {zone!r}. "
+                    "Set exaa_username, exaa_password, exaa_private_key_path, and "
+                    "exaa_certificate_path or the EXAA_* environment variables."
+                )
+            return self._exaa.day_ahead_prices(zone, start, end, resolution=resolution)
         raise DataNotAvailableError(
             f"No data source available for bidding zone {zone!r}."
         )