FPRates API

GET /api/rates/<region>

Returns the current 48 half-hourly slots for the specified region, ordered most recent first.

Example: /api/rates/G

[
  {
    "slot_time_utc": "2026-06-15T22:00:00Z",
    "fp_rate": 17.052,
    "cost_price": 17.052,
    "period_class": "green",
    "source": "edf"
  },
  ...
]

GET /api/ha/<region>/standard-unit-rates/

Same current-48-slot data as /api/rates/<region>, reshaped to match the industry-standard Octopus/Kraken tariff-rates format used by home-automation tools (e.g. predbat). Use this if your tool expects an Octopus-style rates feed rather than fprates' native shape.

Example: /api/ha/G/standard-unit-rates/

{
  "count": 48,
  "next": null,
  "previous": null,
  "results": [
    {
      "value_exc_vat": 16.105,
      "value_inc_vat": 16.9103,
      "valid_from": "2026-06-15T22:00:00Z",
      "valid_to": "2026-06-15T22:30:00Z",
      "payment_method": null
    },
    ...
  ]
}

GET /api/rates/<region>/best

Returns the cheapest N slots of the day, sorted by price ascending. Free (0p) slots always appear first. Ideal for scheduling battery charging.

Parameter: slots — number of half-hour slots to return (default: 8 = 4 hours)

Example: /api/rates/G/best?slots=8

[
  {
    "slot_time_utc": "2026-06-13T11:00:00Z",
    "fp_rate": 0.0,
    "cost_price": 0.0,
    "period_class": "amber",
    "source": "edf"
  },
  ...
]

GET /api/rates/<region>/history

Returns all stored EDF half-hourly slots for a date range, ordered chronologically. Data available from 29th October 2025 onwards.

Parameters:

• start — start date in YYYY-MM-DD format (required)
• end — end date in YYYY-MM-DD format (required)

Example: /api/rates/G/history?start=2026-06-01&end=2026-06-15

[
  {
    "slot_time_utc": "2026-06-01T00:00:00Z",
    "fp_rate": 7.53,
    "period_class": "green"
  },
  ...
]

💡 Excel Power Query: Use the history endpoint to pull data automatically into Excel. See the download page for a ready-to-use Power Query script.

GET /api/rates/<region>/download

Downloads a CSV file of all stored EDF half-hourly slots for a date range. Data available from 29th October 2025 onwards.

Parameters:

• start — start date in YYYY-MM-DD format (required)
• end — end date in YYYY-MM-DD format (required)

Example: /api/rates/G/download?start=2026-06-01&end=2026-06-15

CSV columns: slot_time_utc, local_time, fp_rate, period_class

Prefer a user-friendly interface? Use the CSV download page.

GET /api/forecast/<region>

Returns today + 3 days of predicted rates with wind, solar and demand forecast data. Used to power the forecast charts.

Example: /api/forecast/G

[
  {
    "time": "15 Jun 06:00",
    "fp_rate": 20.602,
    "band": "amber",
    "wind": 1823,
    "solar": 4521,
    "demand": 22100
  },
  ...
]

GET /api/wholesale/<region>

Half-hourly wholesale price comparison: Elexon market index prices (MID) alongside the wholesale cost implied by EDF's published FreePhase rates, back-calculated using EDF's published regional coefficients (C & P). Data available from 29th October 2025 onwards. Add /download to the path for CSV.

Parameters:

• start — start date in YYYY-MM-DD format
• end — end date in YYYY-MM-DD format
• date — single day shortcut (alternative to start/end)

Example: /api/wholesale/G?date=2026-06-27

[
        {
        "slot_time_utc": "2026-06-27T12:00:00Z",
        "local_time": "2026-06-27 13:00:00",
        "fp_rate": 10.7741,
        "band": "amber",
        "edf_implied_wholesale": 5.1799,
        "flag": "ok",
        "mid_wholesale": 2.2853
        },
        ...
        ]

Each slot carries a flag: ok (back-calculation valid), free (0p free period — implies nothing about wholesale), capped (rate hit the 75p ceiling — wholesale not recoverable), missing (no published rate).

Worth knowing: implied wholesale assumes EDF's published formula (rate = wholesale x C, plus P at peak) per half-hour. EDF actually sets one price per band per day from day-ahead wholesale, so implied values reflect the band-level figure EDF used, not the half-hourly market. The gap between the two columns is real and informative — that's rather the point.