How do I get an API key
Welcome - you asked about API keys but just in case - do you need to access the Companies House Public Data API / Streaming API OR do you want to actually file information? For the latter the process is different. For the Public Data / Streaming APIs you will use an API key. I believe the main Companies House instructions are here:
It’s been a long time since we signed up but the instructions here should help:
Essentially - go to:
… and sign up, then choose “Create an Application”.
I would recommend you always choose “live” not test/sandbox. You’ll also need to either list your external IPs OR (if calling via javascript / CORs) the names of domains you’ll be calling from. (If you are just running a locally hosted server use the workaround for this).
Apologies if you have already covered this but the authorization method seems to be a stumbling block for many people. It’s http Basic, and the “user name” is the API key and the password is blank. Many libraries / environments will do this for you ( e.g. the curl utility just allows you to specify a username:password string - so that would be:
your_api_key:
… eg. password part is blank.)
If your library does not you may need to set this using the http headers in the appropriate format (see e.g. article I linked).
Good luck.