Every note, post and subject got a readable address

A link is the unit this platform travels in. Somebody finds a set of notes, pastes it into a class group, and thirty people decide in about a second whether to tap it. For most of this year what they saw was eight random characters, which tells a reader nothing and tells a search engine less.

Notes, community posts and subjects now resolve by a readable name derived from their title. The old identifiers still work and redirect to the new address — an address that has already been shared should never stop working because we changed our minds about how addresses are formed — and the app shares the readable one.

Subjects came with a second problem worth naming. They had existed only as a filter applied to another page, which meant there was no address for "Physics" to link to, no page for a search engine to rank, and nothing to share. They are now paths in their own right. Because renaming a subject would otherwise break every link to it, each one remembers its old slugs and resolves them.

We also closed a hole that had let two subjects claim the same slug, which is the kind of fault that stays invisible until the day one of them silently stops being reachable.