No. It's implemented in native code (Zig) inside bun itself and just exposed to developers as a JavaScript API.

Source code: https://github.com/oven-sh/bun/tree/6ebad50543bf2c4107d4b4c2...

10/10 Loving it (and how fast it is!) - its just not the use-case that fits my needs.

I want maximum ability to "move" my projects among services/vendors/providers

i assume you can just use it[0] in your project and then build (using bun) for cf workers[1]

[0] https://bun.sh/docs/api/s3

[1] https://hono.dev/docs/getting-started/cloudflare-workers \ (https://bun.sh/docs/api/workers ?)