plex-api VS esphome-plex-controller

No connection string necessary, you just have to open com.plexapp.plugins.library.db, which is in the 'Plug-in Support/Databases' folder inside your data directory. Though depending on the context of your original question, it may be easier to just use the web api. Based on the request the web app makes, it will be something like PUT [host]:[port]/library/sections/[section]/all?type=[type]&id=[metadata_id]&summary.value=[url encoded summary]&summary.locked=1&X-Plex-Token=[token]. Not sure if type is needed, but if it is, you can find the values here.

If you want to connect to the API then look for projects like python-plexAPI or the plex-api wiki maybe even the Plex-Meta-Manager can give you pointers on how to get metadata from the outside into plex because that is what it actually does.

using the undocumented api I was able to get a user id & token ( Plex Web API Overview · Arcanemagus/plex-api Wiki (github.com) )

I was able to utilize the HTTP Request component to send control commands to a plex player (macOS Plex Player) using the Plex API. This allows me to directly control the volume, playback and track with two momentary buttons (volume up and down) and a 3-way toggle switch (pause, play, next track). I've published my yaml file to github. The script in the yaml needs to be populated with the server IP address and the 'X-Plex-Target-Client-Identifier' which is the ID of the player being controlled. To find this ID, navigate to http://server_IP_address:32400/clients in the browser, look for the 'machineIdentifier' value of the player to be controlled. Copy that value to the script in ESPHome. Not every player can be controlled, the 'protocolCapabilities' value indicates to what extent each player can be controlled.

Where {section} is the library section, {type} is the media type, and {id} is the item's metadata id. The [ and ] also have to be urlencoded, so a full request might look something like this:

For example, the plex web API can show you which endpoints to hit to do certain things.

I like how you can use things like the web api and the python plex api to make things to do anything you can think of.

Are you capable of doing simpleish programming? If so, the there is always the google home API + the plex api and creating you're own skill to do it. If you're looking for something ready made then phlex is the only option I'm aware of on that front. The custom skill way is a good way to learn some basic programming and also how to create google/alexa skills if you have to go that route.

Plex has a API https://github.com/Arcanemagus/plex-api/wiki/Plex-Web-API-Overview

There's no official documentation, but yes. There is some unofficial documentation here, and as an example, the following would change the title (and lock the field) of the item with a metadata id of 365480 in the library with a section ID of 3:

I was able to utilize the HTTP Request component to send control commands to a plex player (macOS Plex Player) using the Plex API. This allows me to directly control the volume, playback and track with two momentary buttons (volume up and down) and a 3-way toggle switch (pause, play, next track). I've published my yaml file to github. The script in the yaml needs to be populated with the server IP address and the 'X-Plex-Target-Client-Identifier' which is the ID of the player being controlled. To find this ID, navigate to http://server_IP_address:32400/clients in the browser, look for the 'machineIdentifier' value of the player to be controlled. Copy that value to the script in ESPHome. Not every player can be controlled, the 'protocolCapabilities' value indicates to what extent each player can be controlled.