Basics
So you want to develop an SDK? Before you get started here are some basics that are worth following to have a better experience.
You do not need a local Sentry for SDK development but you will want to run a local relay. The reason for this is that Sentry's main ingestion endpoint is not intended for development but for high throughput production use. What this means is that a lot of the event processing is happening after the event has already been accepted by the system so you won't be able to see errors when sending the HTTP request.
If you haven't used relay yet, have a look at the getting started docs for relay. Once installed you will want to turn up the log level in your .relay/config.yml file:
logging:
level: trace
Make sure your relay is running whenever you're doing development:
relay run
When sending events just substitute orgXXX.ingest.sentry.io with localhost:3000 or whichever port you ended up chosing. Also note that a local relay will out of the box be available via HTTP only so don't try to send HTTPS requests there.
You can reach out to Sentry open source contributors and talk with other SDK maintainers on the Sentry Discord server.
While we're trying to keep the docs up to date about all important things, it's usually a good idea to refer to already existing Sentry SDKs for input. In particular the transport design is not part of the documentation but generally quite similar between SDKs.
Our documentation is open source and available on GitHub. Your contributions are welcome, whether fixing a typo (drat!) or suggesting an update ("yeah, this would be better").