A visual editor for block models of systems: nested areas, relationships, evidence and checks, saved as craggy.model JSON.
Connect to the MCP server at https://models.craggy.io/mcp (streamable HTTP, no accounts, nothing stored). Its tools import, check, edit, query and export models, and model_open returns a link that opens a model here.
Claude Code: claude mcp add --transport http craggy-models https://models.craggy.io/mcp
Full guide: https://models.craggy.io/llms.txt. Source: github.com/craggy-io/modelling-services.