The PHP client is community supported. This doesn’t mean that Aerospike doesn’t work on it, but that this development lags other clients. It is not as up to date on features as higher tiered clients. Part of the issue is less involvement by PHP users compared to the Rust client, which is in the same tier of clients.
You should take a look at the REST client, which is language agnostic, scales and performs well under heavy loads. It is used in production, it is under active development, and it has features that are missing in the PHP client. You can use it right now.
There is a REST client interface for PHP, aerospike-community/aerospike-client-rest-php. It’s an example of a client generated from the Swagger doc of the REST client itself.
You can find articles about the REST client on the Aerospike Developer Blog in Medium and DEV.