hello.
i want to get my electricity consumption into home assistant, so i tried the ovo add-on and the glow add-on but they are no good because they are either delayed by several hours or wildly inaccurate. is there a way to receive the transmissions from the smart meter directly? if so, what do i have to do?
And, the model of your smart meter is top secret? 
the problem is that i live in a rented flat, and the smart meter is in a room that i cannot get into.
We have to assume that you live in the UK, although smart meters are available in a number of countries.
We have to assume that you have a Smets1, although Smets2 are available.
Smart meters are really quite stupid. In the UK, these meters record internally energy use and cost for each 30 minute period going back for 13 months. The cost is computed based on a tariff array for upcoming periods with both standing charge and unit charge held in the meter.
The meter has a GSM connection to a backbone network, and connects once a day during the night, to upload the prior day energy use, and to download any tariff changes or supplier messages.
From this energy use, the applicable supplier adds the use and recalculated cost to each user account, at some point during the day after. Some HA integrations can get this user account information, which is clearly always at least half a day old.
As a nice to have feature, the electricity meter typically has a HAN - home area network - which can be connected to from an in-home display. These units show current near real time use, as well as indicative cost, and accumulated figures.
To get real time (or as close to real time as is possible) the HAN is the only source of data from the Smart Meter. Other solutions are to use a CT clamp and external meter and do the voltage and current (and power factor) readings as DIY, which may be possible for you if you have a Consumer Unit as the main supply point to your flat.
From the HAN, options include using IHD with output connection such as the Hilderbrand Glow together with a suitable HA integration, where the Glow acts as a Consumer Access Device.
Octopus Energy provide a Mini device, which can be registered to the meter, and then will send live consumption data directly to your Octopus account via the home internet connection. The HA Octopus Energy Integration can, where a Mini is available, pull down real time power and energy figures.
The Mini only needs a USB type power supply point, and to be in range of the smart meter. I find the HA Integration updates every 2 or 3 minutes, which is near real time, and compares well enough with my solar inverter which reports, from a CT clamp meter, every 15 seconds via my own Modbus polling.
If you are in the UK and if you can switch to Octopus Energy and if you can still get a Mini and if you are near enough to the locked meter room and if you can register the Mini to your meter and Account and if you can add the Octopus Integration and if you set this up correctly, then yes it should work for you too.