Can we get access to the OVO energy online account API to download our smart meter usage data?

​@Firedog 

This is what my daily usage looks like on the website on my phone, as you can see it correctly starts at 00:00 BST

​@Firedog 

Is the difference an electric only quirk???

If I remember correctly you are electric only customer.

​@Firedog I have sussed the difference.

The OVO website calls

https://smartpaymapi.ovoenergy.com/usage/api/half-hourly-local/nnnnnnn?date=2025-10-09

Which gives the date stamps in UTC

Whereas my app calls

https://smartpaymapi.ovoenergy.com/usage/api/half-hourly/nnnnnnn?date=2025-10-09

Which gives the date stamps in local

Quite clearly the -local version is wrongly named I would have called it -utc

For those enquisitive people you can switch my app from local timestamps to UTC by changing AppSettings.json from this

{
    "LoginUri": "https://my.ovoenergy.com/api/v2/auth/login",
    "TokenUri": "https://my.ovoenergy.com/api/v2/auth/token",
    "AccountsUri": "https://api.eu1.prod.kaluza.com/graphql/1",
    "MonthlyUri": "https://smartpaymapi.ovoenergy.com/usage/api/monthly/{0}?date={1}",
    "DailyUri": "https://smartpaymapi.ovoenergy.com/usage/api/daily/{0}?date={1}",
    "HalfHourlyUri": "https://smartpaymapi.ovoenergy.com/usage/api/half-hourly/{0}?date={1}",
    "DumpData": "true"
}

to this

{
    "LoginUri": "https://my.ovoenergy.com/api/v2/auth/login",
    "TokenUri": "https://my.ovoenergy.com/api/v2/auth/token",
    "AccountsUri": "https://api.eu1.prod.kaluza.com/graphql/1",
    "MonthlyUri": "https://smartpaymapi.ovoenergy.com/usage/api/monthly/{0}?date={1}",
    "DailyUri": "https://smartpaymapi.ovoenergy.com/usage/api/daily/{0}?date={1}",
    "HalfHourlyUri": "https://smartpaymapi.ovoenergy.com/usage/api/half-hourly-local/{0}?date={1}",
    "DumpData": "true"
}

It might be prudent to delete/rename the file {accountNo}.db from the folder C:\ProgramData\OvoData before trying this out.

/MIke

Just done an experiment using the endpoint “api/half-hourly” vs “api/half-hourly-local” and I have found that my program is over writing some of the values.

api/half-hourly (which gives local time)

As you can see for the last change over date two readings have been over written.
 

api/half-hourly-local (which gives UTC)

So I would recomend altering the appsettings.json as follows

"HalfHourlyUri": "https://smartpaymapi.ovoenergy.com/usage/api/half-hourly-local/{0}?date={1}",

​@Firedog It will be interesting to see which API the OVO web site calls after we switch back to GMT

​@MikeWilliams Thanks for looking into this. I went cross-eyed on Sunday trying to find out why I first complained about this BST nonsense and decided to do other stuff yesterday in the hope that I could get back to it with a clearer brain this morning. Now I find you’ve beaten me to it!

We have several sources of usage data, and they all have their own way of presenting the figures. This can make it easy for the unwary to get waylaid if data from different sources are mixed up. I did a comparison some time ago to illustrate how the same dataset called up by date can produce really different results:
  

Of these, the only really accurate one is n3rgy - the meter time-stamps each half-hour bucket as it becomes full and moves on to the next, so the one that starts filling up at midnight is labelled 00:30. The various utilities then apparently change the time stamps to what they think the end-user wants. 

We’ll find out soon what happens at the end of summertime. I think they’ve got it about as good as can be expected. During GMT, there’s no need for the weird first-hour entry on a placeholder page before the day’s data have been retrieved.  

​@MikeWilliams & ​@Firedog thanks for your efforts and work on this.

Just thought I’d double check -  is there any way to get the data for this property’s smart meter from the last 400 days as has been mentioned by some previously? (Or any X number of days, as opposed to just for this account)

Thank you!

I am currently working on the code to get the last 400 reading for this account.

Not sure how you would get readings for an account that is not yours.

Please explain further ​@X10 ?

The OVOData utility retrieves the data stored by OVO in the user account. It doesn’t know or care which meter originally recorded the data. The last 400 days’-worth will of course be included in the All Time dataset so long as the account is old enough.

You may have read that a SMETS2 smart meter records both a daily snapshot of the register readings at midnight and every half-hour’s usage, storing the former for 30 days and the latter for 400 days. Old records are deleted to make space for new ones. 

Some third-party utilities can access the meter’s usage data store with the customer’s permission. The ones I use - Bright and n3rgy - limit data retrieval to three months’-worth, but they might be persuaded to download the whole lot if you ask them nicely.