Bid Strategies:

Maximize Conversions: tries to get as many conversions as possible for your set budget

Target CPA (Cost Per Action): allows you to set a "cost per conversion" target.
Works best if you have at least 15 conversions (ideally 30) per month.
Often people run "maximize conversions" for a while to get some data, then they look
at what CPA they got out of that, and finally they set a "tCPA" at or just above that
measured CPA value.
If you're selling a product for 100kr and it costs you ~30kr to produce the product
(i.e. the non-google ads costs), then paying 70kr per conversion means that you
sell a lot of product but you make zero profit. Therefore you must set a "tCPA"
(Target Cost per Action) lower quite a bit lower than 70kr.

Target ROAS (Return on Ad Spend): Set a ratio for how much money (conversion value) you want back
given you ad spend (cost). Works best if you have at least 15 conversions (ideally 30) per month.
Often people run "maximize conversions" for a while to get some data, then they look
at what ROAS they got out of that, and finally they set a "Target ROAS" at or just above
that measured ROAS value. The current ROAS is shown in the metric called "Conv. value/cost".
The reason Google doesn't call the column ROAS is because it's quite common for people
to assign arbitrary currency amounts to different conversion event types just to steer
the ad optimization AI for lead generation events etc.


Note: "Cost per Action" (CPA) refers to "Cost per conversion" but they could not
call it "Cost per conversion" because then the abbreviation would be CPC and when
google ads was built, CPC was already very prominently used to refer to
"Cost per Click". Also, "Cost per Action" (CPA), sometimes also called
"Cost per Acquisition" was already an established term that people understood.
The action can be very broad and doesn't necessarily refer to a purchase or a
new customer signup; it can also be lighter actions like "subscribing to a newsletter",
"playing a video" or an "add to cart" etc.
is "Target cost per action (tCPA)" the sort of the same as "Target cost per conversion" ?


Change history is limited to 30 last days when queries via API (use UI for full change history)
Action Insights is not available via the API

https://github.com/googleads/google-ads-python is the official python library (can access non-GAOL parts of the API like Keyword Planner)
https://github.com/googleads/google-ads-mcp is an official google ads MCP (has GAOL query support)
https://github.com/google/ads-api-report-fetcher is good for batch queries from CLI
https://github.com/getyourguide/gaql-cli might be better for interactive/REPL use cases (warning, it append limit 100 silently when limit is not specified)