Uploads
files, sizes, disk and slots.

01What can be uploaded

The server reads the type from the file's content, never from its name or declared type:

The caps are set in the console under Media caps and thresholds. A screenshot is an image: when the language model is set, it is first read as a screenshot (see Checks).

02The upload size limit

Every request to /v1 is limited to 256 KB, except a file check. A file check may be as large as your largest file cap plus 1 MB for the form around it: about 101 MB with the default 100 MB video cap, about 201 MB with the 200 MB maximum. If you run a reverse proxy, allow at least that request size there too (nginx: client_max_body_size).

On the phone, the share extension and the Android share entry copy a shared file only when it is within the server's default cap of its kind (image 12 MB, audio 20 MB, video 100 MB, e-mail 10 MB), and never more than 101 MB. A larger file is not copied, and the app says why.

03What happens to an upload

1. Before any byte is read: the app's signature, its request nonce and the per-install rate limit are verified, and the upload must declare its length (Content-Length) and the SHA-256 of its body (x-rc-body-sha256).
2. Streaming to disk: the body is written to a private folder while it is hashed. A body whose hash differs from the declared one is deleted and refused.
3. Checking the file: not empty, a supported type, within the size cap of its type, and for audio and video within the length cap. Then it is copied once more under a random name and the streamed body is deleted.
4. After the check: the file is deleted when the check ends, also when it fails or is stopped. Leftovers from a crash are swept at every start and every hour.

The app shows a refusal in the person's language. The reasons are: empty, unsupported type, too large, too long, and length could not be read.

04Temporary disk you need

Uploads are written to a private folder under the system temp folder of the server (owner-only, mode 0700). The server refuses to start when that folder belongs to another user or others can open it. Each upload is on disk twice for a moment (the body, then the checked copy), so plan free space for about:

2 × largest file cap × uploads at once
# defaults: 2 × 100 MB × 8 = about 1.6 GB
# 200 MB video cap: 2 × 200 MB × 8 = about 3.2 GB

In Docker the system temp folder is inside the container; give the container that much writable space.

05Upload slots

Over a slot limit the server answers 429 (too many uploads at once); a stalled upload gets 408 and its slot is freed at once; an upload without a length gets 411. Raise UPLOAD_MAX_CONCURRENT only together with the disk space above.

06What a file costs in daily units

An image is 1 media unit, audio 1 unit per started minute, and video 10 units per started 30 seconds. A screenshot read as a message costs its 1 media unit and no light check. When a provider fails on a media check, its units are given back. Units count against the install's daily allowance in Plans.