Anthropic Announces Japan Claude Code Hackathon for November 2026

Anthropic and the AI community Cerebral Valley have announced an online hackathon for Japan residents using the AI coding tool Claude Code, called 'Built with Claude: Japan 2026'. The event runs from November 2 to November 10, 2026, according to gamebusiness.jp.

Participation is by selection, with a capacity of 250 people, and applications are accepted until October 26. The hackathon is fully online and requires being a resident of Japan. Teams can have up to 2 people, and all team members must apply and pass the selection.

Participants receive Claude's paid plan 'Max 5x' — 100 USD per month, five times the usage of Pro — along with 500 USD of Claude API credits. Prizes for winners total 50,000 USD worth of API credits, not cash. The judges will be announced soon.

Earlier Claude hackathons

Anthropic has held Claude hackathons in Japan before, though this is the first that can be joined online from anywhere in Japan. In February 2026, 'Built with Opus 4.6' was held as the first hackathon of the 'Built with' series, followed by 'Built with Opus 4.7' in April 2026 and the life-sciences-focused 'Built with Claude: Life Sciences' in July 2026. Each of those three had a capacity of 500 people and a total prize pool of 100,000 USD, with 500 USD of API credits for participants in the Opus 4.6 and Opus 4.7 editions.

According to Anthropic, four of the five winners of the first edition were not professional developers but lawyers, doctors and musicians. In September 2025, 'Claude Hackathon 2025 in Tokyo' was held from September 5 to 7, organized by KERNEL by DEEPCORE and co-hosted by Anthropic × KERNEL as a hybrid event with a Tokyo venue and Zoom, offering prizes such as 3,000 USD of API credits for first place. In June 2026, Anthropic held the developer event 'Code with Claude Tokyo' in Tokyo.