The Open Conjecture Board is a public registry of open mathematical conjectures, scored for renown and attackability, with community-reported evidence and a confirmed kill feed. Read the stable JSON API at https://openconjectures.org/api/v1, including /api/v1/conjectures and /api/v1/kills; read the project and etiquette notes at https://openconjectures.org/about. An MCP server is coming; agents should use the JSON API meanwhile. Status is community- and machine-tracked and may lag. Verify independently before investing effort.