py-nationalgrid

Async Python client for National Grid's GraphQL and REST APIs.

Installation

pip install py-nationalgrid

Quick Start

import asyncio
from py_nationalgrid import NationalGridClient, NationalGridConfig

async def main() -> None:
    config = NationalGridConfig(
        username="user@example.com",
        password="your-password",
    )

    async with NationalGridClient(config=config) as client:
        accounts = await client.get_linked_accounts()
        for account in accounts:
            acct_id = account["billingAccountId"]
            next_read = account["billingAccount"].get("nextSchedReadingDate")
            print(f"Account: {acct_id}  next read: {next_read}")

            # Single call: balance, autopay, paperless, scheduled payments, recent bills
            dashboard = await client.get_account_dashboard(acct_id)
            print(f"  Balance: ${dashboard['currentBalance']:.2f}")
            print(f"  Paperless: {dashboard['paperlessBilling']['status'] if dashboard['paperlessBilling'] else 'N/A'}")
            print(f"  Autopay: {'enrolled' if dashboard['isEnrolledInRecurringPay'] else 'not enrolled'}")
            for bill in dashboard["recentBills"]:
                print(
                    f"  {bill['statementDate']}  due {bill['dueDate']}  "
                    f"${bill['totalDueAmount']:.2f}"
                )

if __name__ == "__main__":
    asyncio.run(main())

API Methods

Method	Returns	Description
get_linked_accounts()	list[AccountLink]	Linked billing account IDs and next scheduled meter read date
get_billing_account(account_number)	BillingAccount	Account details: region, address, fuel types, and meter info (including smart meter flags)
get_bills(account_number)	list[Bill]	Bill history, newest first — statement date, due date, charges, and status
get_energy_usage_costs(...)	list[EnergyUsageCost]	Daily energy costs for a billing period
get_energy_usages(...)	list[EnergyUsage]	Monthly historical usage data
get_ami_energy_usages(...)	list[AmiEnergyUsage]	Primary AMI method. Tries the daily NrtDailyUsage endpoint first (no chunking required). Falls back to get_ami_energy_usages_15min() automatically on GraphQL errors or 504. See below.
get_ami_energy_usages_15min(...)	list[AmiEnergyUsage]	AMI 15-minute interval data. Call directly only when you specifically need 15-minute granularity. Auto-chunks large ranges, falls back to daily on API errors, and handles the ~45-day hot storage limit gracefully.
get_payment_history(account_number)	list[Payment]	Payment history — payment date, amount, status, method, and error info
get_account_dashboard(account_number)	AccountDashboard	Account summary — balance, autopay/paperless status, scheduled payments, and recent bills in one call
get_paperless_billing(account_number)	PaperlessBilling | None	Paperless billing enrollment status
get_balanced_billing(account_number)	BalancedBilling | None	Budget billing plan status and monthly payment details
get_payment_plans(account_number)	list[PaymentPlan]	Active payment plans — installment amounts, counts, and status
get_collection_arrangements(account_number)	list[CollectionArrangement]	Collection arrangements — total due, installment schedule, and status
get_meter_reading(account_number)	MeterReading | None	Current meter read eligibility and last submitted reading
get_interval_reads(...)	list[IntervalRead]	Real-time meter interval reads. Returns [] for meters with no interval data (e.g. GAS).
get_premise(...)	list[PremiseNode]	Look up premise number and meter info by address. Does not require authentication.
get_electric_bill_history(account_number, customer_number)	list[ElectricBillRecord]	Per-billing-period electric data: utility/supplier charge breakdown, total kWh, avg daily usage, and demand fields (TOU, peak kW). More detail than get_bills().
get_gas_bill_history(account_number, customer_number)	list[GasBillRecord]	Per-billing-period gas data: utility/supplier charge breakdown, total therms, avg daily usage. More detail than get_bills().

All methods return typed results using TypedDict models.

AMI Energy Usage

Primary method: get_ami_energy_usages()

This is the recommended entry point for AMI data. It sends a single full-range request to the NrtDailyUsage (daily) endpoint — no chunking required. If that request returns GraphQL errors or a 504 Gateway Timeout, it automatically falls back to get_ami_energy_usages_15min() (with chunking) and returns whatever that produces.

from datetime import date, timedelta

date_to   = date.today()
date_from = date_to - timedelta(days=60)

usages = await client.get_ami_energy_usages(
    meter_number=meter["meterNumber"],
    premise_number=billing_account["premiseNumber"],
    service_point_number=meter["servicePointNumber"],
    meter_point_number=meter["meterPointNumber"],
    date_from=date_from,
    date_to=date_to,
    fuel_type=meter.get("fuelType"),   # forwarded to the fallback path if triggered
)

Explicit 15-minute method: get_ami_energy_usages_15min()

Use this directly only when you specifically need 15-minute interval granularity. It handles several API constraints automatically.

Chunking

The National Grid API imposes a hard limit of approximately 10,000 records per response, and the Azure Application Gateway enforces a backend timeout on large requests.

The method automatically splits any date range that exceeds 60 days into 60-day chunks and concatenates the results. Chunks are requested newest-first to ensure the most recent data is always fetched before older chunks that may hit the cold-storage boundary. Each chunk is logged at DEBUG level.

If a 60-day chunk returns a 504 Gateway Timeout or a request timeout, the method automatically retries that chunk split into 45-day sub-chunks before giving up:

WARNING amiEnergyUsages15Min: request failed on 60-day chunk 4/7 (2025-11-04 to 2026-01-02) — retrying as 45-day sub-chunks.

Hot Storage Window (~45 days)

National Grid's API only serves data from "hot" (immediately accessible) storage for approximately the last 45 days from today. Data older than that sits in cold/archive storage. Any query that touches cold storage will trigger a 504 Gateway Timeout or a request timeout.

This is a server-side constraint. There is no client-side configuration that can change it.

Because chunks are fetched newest-first, a failure on an older chunk does not discard the recent data already collected. When a 45-day sub-chunk also times out, the method logs a warning and returns whatever records were successfully retrieved:

WARNING amiEnergyUsages15Min: request failed on sub-chunk (2025-09-05 to 2025-10-19) —
data is likely beyond the ~45-day accessible window. Returning 19101 record(s)
collected so far.

Callers should not assume the returned list covers the full requested date range. If you request 365 days, you will receive roughly the last 45 days of records without an exception being raised.

Fallback to Daily Endpoint

Some meters do not support the 15-minute (amiEnergyUsages15Min) GraphQL operation and return a GraphQL error response instead of data. When this happens on the first chunk, the method transparently falls back to a single full-range request against the standard daily endpoint (amiEnergyUsages). The fallback is automatic and invisible to the caller.

Example

from datetime import date, timedelta

date_to   = date.today()
date_from = date_to - timedelta(days=90)   # > 60 days → auto-chunked into 60-day windows

usages = await client.get_ami_energy_usages_15min(
    meter_number=meter["meterNumber"],
    premise_number=billing_account["premiseNumber"],
    service_point_number=meter["servicePointNumber"],
    meter_point_number=meter["meterPointNumber"],
    date_from=date_from,
    date_to=date_to,
    fuel_type=meter.get("fuelType"),   # "ELECTRIC" or "GAS"; controls chunk size
)
# usages may cover less than the full range if older data is beyond the ~45-day window

Premise Lookup

get_premise() targets the premise-cu-uwp-gql endpoint, which does not require authentication. Any address in National Grid's service territory can be queried to obtain the premise number and associated meter information:

premises = await client.get_premise(
    city="Anytown",
    state="NY",
    street_name="1 Example Road",
    zip_code="12345",
)
for p in premises:
    print(p["premiseNumber"], p["premiseStatus"])
    for m in p["meter"]["nodes"]:
        print(m["meterNumber"], m["fuelType"])

Examples

uv run python examples/list-accounts.py      --username user@example.com --password secret
uv run python examples/account-info.py       --username user@example.com --password secret
uv run python examples/billing-info.py       --username user@example.com --password secret
uv run python examples/bill-history.py       --username user@example.com --password secret
uv run python examples/payment-history.py    --username user@example.com --password secret
uv run python examples/account-dashboard.py  --username user@example.com --password secret
uv run python examples/energy-usage.py       --username user@example.com --password secret
uv run python examples/interval-reads.py     --username user@example.com --password secret
uv run python examples/ami-usage.py          --username user@example.com --password secret
uv run python examples/ami-usage.py       --username user@example.com --password secret --fuel-type ELECTRIC
uv run python examples/ami-usage.py       --username user@example.com --password secret --fuel-type GAS --days 30
uv run python examples/ami-usage.py       --username user@example.com --password secret --15min

# Premise lookup (no auth required)
uv run python examples/premise-lookup.py  --street "1 Example Road" --city Anytown --state NY --zip 12345

Development

Requires Python 3.13+ and uv.

uv sync                # install dependencies
uv run pytest          # run tests
uv run ruff check .    # lint
uv run ruff format .   # format
uv run mypy src        # type-check