Files: upload and download

Binary content — contribution cover images, puzzle test-case data — isn't carried inline in the service API. It's referenced by numeric ID and moved through two servlets.

Downloading

async with CgClient() as client:
    result = await client.servlets.file_servlet(binary_id)
    path.write_bytes(result.content)

CgDownloadFileResult carries the bytes, the content type, and the filename from Content-Disposition if the server sent one.

Content is returned as bytes, not text, and written to disk that way. Puzzle test-case files are the reason: they are the server's own artifacts, and a local run has to feed a solution's stdin exactly what CodinGame feeds it. Decoding and re-encoding is where that guarantee gets quietly lost.

Some files are publicly downloadable. require_login=False lets the server decide with a 401/403 rather than the client refusing up front.

The CLI equivalent:

cg api file-servlet <ID> > cover.png

Uploading

binary_id = await client.servlets.file_upload(data, filename="cover.png")

Returns the new object's ID, which you then reference from whatever you're saving — for a cover image, CgContributionData.cover_binary_id.

cg api file-upload < cover.png

A caution about orphans

An upload with nothing referencing it is an orphaned object on CodinGame's servers. A handful are harmless; producing them in bulk — a test suite that uploads on every run, say — is the kind of pattern that gets accounts flagged.

Uploads attached to something you're managing are fine. cg contribution push uploads a cover image only when it has changed, and reuses the existing ID otherwise, precisely so that repeated pushes don't leave a trail of dead objects.