Upload media from a URL

Download a file from a URL and upload it to your media library — the recommended path for MCP/programmatic uploads. Supports videos up to 1 GB: files over 100 MB are streamed to storage by a background worker and the response returns 202 with the item in processing state (poll GET /media/{id} until status is ready). Files at or under 100 MB upload inline and return 201 ready. A PDF URL is split into image slides and returned as a carousel (see PdfUploadResult; pass all of media_ids to POST /posts). Every response also includes a compatibility block listing any connected platforms that would reject the file by size or format.