aranet-cloud

Async Python client for the Aranet Cloud REST API.

Wraps the public Aranet Cloud OpenAPI 3.0 spec — 25 of its 27 read-only GET endpoints (all but the two attachment-metadata endpoints) — and returns typed dataclass models. Designed primarily as the backing library for the aranet-cloud-homeassistant HACS integration, but usable as a standalone Python client.

Status: Alpha (0.2.x). The OpenAPI mapping is stable; the public Python surface may still evolve as the HA integration drives requirements. Pin to a minor version in production.

Install

pip install aranet-cloud

Python 3.11+ required. Single runtime dependency: aiohttp.

Quick start

import asyncio
from aranet_cloud import AranetCloudClient

async def main() -> None:
    async with AranetCloudClient(api_key="...") as client:
        # List every sensor on your account
        sensors = await client.get_sensors()
        for s in sensors:
            print(f"  {s.serial}  {s.name:<30s}  type={s.type}")

        # Latest reading per (sensor × metric), with name resolution
        readings, links = await client.get_measurements_last()
        for r in readings:
            metric = links.name("metric", r.metric) or r.metric
            unit   = links.name("unit",   r.unit)   or r.unit
            print(f"  {r.sensor:>10s}  {metric:>22s}: {r.value} {unit}")

asyncio.run(main())

Output against a typical home/garden account:

  A0005  Bedroom               type=S4V1
  A0001  Kitchen                       type=S4V1
  ...

  4000005           Temperature: 72.5 °F
  4000005              Humidity: 30 %
  4000005                    CO₂: 757 ppm
  4000005   Atmospheric Pressure: 697.9 mmHg
  ...

Authentication

The Aranet Cloud API uses a single header — ApiKey: <your-key>. No OAuth, no token refresh. Generate a key from your Aranet Cloud dashboard under Account → API.

AranetCloudClient(api_key="vku...")

What's covered

25 of the 27 GET endpoints in the public OpenAPI spec (all but the two attachment-metadata endpoints — the file/thumbnail downloads are wrapped):

See docs/architecture.md for the full API reference, edge cases discovered during live probing, and design notes.

Pagination

History endpoints are paginated by the server. The library hides the mechanics via async iterators:

async for reading in client.iter_measurements_history(sensor="4000005", hours=24):
    print(reading.time, reading.value)

The iterator follows the next token transparently until the server returns no more data. Mind the time windows — /measurements/history without a sensor filter caps at 7 days; with a sensor filter it caps at 6 months.

Exception hierarchy

AranetError                       ← base; catch this for a blanket handler
├── AranetConnectionError         ← network, timeout, TLS, DNS
├── AranetAuthError               ← 401 (key wrong/missing/revoked) - NOT transient
├── AranetValidationError         ← 400 (carries correlation_id from API)
├── AranetRateLimitError          ← 429 (with retry_after if present)
├── AranetServerError             ← 5xx after exhausted retries
└── AranetNotFoundError           ← 404 (rare; API often returns 200 {} instead)

Auth errors deserve special handling — the Aranet API returns 401 as plain text (not JSON), so AranetAuthError doesn't carry a correlation ID. Validation errors are JSON with error[].id correlation tokens, preserved on AranetValidationError.correlation_id for support escalations.

Design

• Async-first (aiohttp). Use as an async context manager (auto session) or inject an existing ClientSession — the HA-friendly pattern.
• Typed: every response shape modelled as a dataclass with from_dict that ignores unknown fields, forward-compatible with new server fields.
• Pagination hidden: iter_*_history() async generators follow next tokens transparently.
• Retry/backoff on 5xx, 429, and transient network failures. Exponential backoff 1s, 2s, 4s, … capped at 30 s; 3 retries by default (so 1s, 2s, 4s). A server Retry-After on 429 is honoured — also clamped to the 30 s cap, so a hostile/misconfigured value can't stall the caller.
• Polite-spacing floor (250 ms) between successive requests. The Aranet API has no documented rate limit, but we don't hammer.
• Never logs the API key. Debug logs cover request method, path, status, and body size; the key is in headers only.

Standalone usage outside Home Assistant

The library has no HA dependencies and is fine to use in standalone Python scripts, FastAPI services, data-ingestion pipelines, etc.:

async with AranetCloudClient(api_key="...") as client:
    # Pull 24 hours of CO₂ readings for a single sensor
    readings = [
        r async for r in client.iter_measurements_history(
            sensor="4000005", metric="3", hours=24,
        )
    ]
    print(f"got {len(readings)} CO₂ samples")

Development

git clone https://github.com/jasonjhofmann/aranet-cloud
cd aranet-cloud
python -m venv .venv
source .venv/bin/activate
pip install -e ".[dev]"

pytest               # 50 tests
ruff check .         # lint
mypy src             # type-check (strict)
uv build             # build wheel + sdist (what CI publishes)

License

Apache 2.0