Open-source Claude Design rival hits 77k stars, 1M+ installs
Open Design, an open-source Claude Design rival, hit 1M+ installs and 77k GitHub stars using a file-first, agent-driven build method.
Eleven days after Anthropic launched Claude Design, a small Shanghai team shipped Open Design, an open-source, local-first alternative that routes through any coding agent a user already pays for. The first build took one person two days plus a day of debugging, cost about $200 in agent subscription fees, and came to roughly 18,700 lines of code.
Since launch, Open Design has crossed one million installs against 77,000 GitHub stars — a ratio that inverts the usual open-source funnel — while giving away the core product under Apache-2.0. The workflow is file-first: humans write the contracts (a DESIGN.md schema, adapter type definitions, security boundaries) and agents write nearly all implementation, validated against replay-based mock CLIs built from sanitized traces instead of live token spend.
For engineers, the real value is the reproducible method: define the contracts humans must own, hand implementation entirely to agents, and validate before merging. The founder argues a solo builder can match today's construction speed, but not the human-speed response to early users and contributors after launch — a part no agent can substitute for yet.