ARIA is an open-source repository intelligence platform that helps developers understand unfamiliar codebases before making changes. It builds a structural view of repositories using AST-based analysis, symbol indexing, dependency graphs, call graphs, API surface analysis, semantic retrieval, and repository-aware AI. ARIA can help developers explore dependencies, trace calls, understand module relationships, assess potential change impact, and query repository knowledge through AI. It also supports MCP integration and can be self-hosted with Docker.