Start a personal file upload

Save an original conversation attachment in your private personal files. Read the attachment bytes with the agent host; never reconstruct an image from its appearance or replace a file with a summary. Reserve a path and its exact byte size. Most file types, including images, up to 100 MiB; 100 files and 1 GiB reserved per member independently of task quotas. Paths are relative logical names and never overwritten. Returns id; upload sequential chunks then complete_my_file. This never grants access to another member. Programs, installers, disk images, shortcuts, and macro-enabled Office files are refused by name. Windows, macOS, and Linux programs, Office macros, password-protected zip files, zip files that contain programs, and PDFs with visible script or launch actions are also refused by content; completing such an upload removes it.