Show HN: CopilotTextarea: <Textarea/> W GPT Completions Like Gmail/GitHub. OSS (github.com)

`<CopilotTextarea />` is a drop-in `<textarea/>` replacement (looks identical & supports all customizations & params) w GPT completions (like in Gmail / GitHub Copilot).

It's built with slateJS and works with any OpenAI-compatible endpoint (bring your own backend).

You pass it a "purpose" prompt & external context to inform completions. E.g. the demo gif[1] has a purpose of "COOL and SLICK announcement post", and was given the CopilotKit release notes as context. (super important, to make suggestions specific).

Part of CopilotKit (open-source copilot/sidekick infra).

IMO it works really well. After working with it in all my apps for the past week it's honestly very frustrating to not have it available universally.

[1]: https://github.com/RecursivelyAI/CopilotKit