Anthropic shipped Fable 5.1, its newest model, the week of 1 September. On Saturday 19 September, Nairobi builds on it for an entire night, one of the first cities in the world to run a Build Day on it.
You pick one of three tracks: Delight, Breakthrough, Everyday. Briefs land on the day. Every approved builder gets $100 in Claude API credits.
Demos are judged live in the room, on four equal criteria from Anthropic's Build Day scorecard: New Capability, It Works, Keep or Share, Clarity of Demo.
On 2 September, at Impact Lab 02, a team built an offline tool for a Grade 10 teacher preparing a strand she was never trained for, with Claude reading a curriculum knowledge base. They called it Elimu Mtaani. It won, out of 19 live demos by the close. The builders rated that day 4.5 out of 5. This one runs on the newest model Anthropic has. Find the thing it makes possible, and show the room.
Come solo, and we match you. Or share and apply with your team. Bring a laptop and charger. Free entry, application required. Your credits attach to a console.anthropic.com Organization, never a personal claude.ai account. Set yours up before Saturday, or we do it together at the door.
By demo time your build is either running or it is not. Karibu.
