Signed commits get the picture
Your app can now attach up to three photos to a commit, reply, or quote, descriptions included. Pictures and text travel together in one signed request.
You're in the app with three photos from the weekend and a commit half typed. You pick them, add a description to the first, and hit send. The commit comes back with the images listed under it in the order you attached them, descriptions and all.
Credit goes to simonhamp, who wired the signed API into the web composer's image pipeline. A request can carry three images, whether you're posting, replying, or quoting. Each can be up to 10 MB and 6,000 pixels a side, with descriptions up to 1,000 characters. The JSON body travels as a file part named payload, the photos under images[], and nothing else in the form. The signature covers a comma-separated SHA-256 hash of each image in order, so a swapped, reordered, or missing photo fails. Each image is re-encoded to WebP at most 1,600 pixels a side, metadata stripped.
One catch. Images on a commit that isn't live yet come back with a temporary link instead of the plain one. That link opens for anyone who holds it, even after the commit is rejected, for up to two hours. After that your app must fetch the commit again for a fresh one.