Red Hat's Ripwire Cuts Coding Agent Token Use by 96% Without Embeddings

Red Hat's Emerging Technologies group has released ripwire, a command-line tool that gives coding agents structural context on any repository in tens of milliseconds, with no embeddings, vector databases, or index server required. It parses your tree, builds a ranked call graph, and streams a deterministic XML map to stdout that a model can pull through an MCP server mid-task.

Ripwire is a zero-runtime-dependency C++23 binary. It crawls a repository tree, extracts symbols with tree-sitter, resolves references into a call graph, ranks that graph with Personalized PageRank, and streams minified XML to stdout. Two runs over the same tree produce byte-identical output, and warm runs match cold ones, enforced by CI on every push.

Why agents burn tokens on cold repos

When an agent lands in an unfamiliar repository, it typically greps for a keyword, opens files, follows imports, and spends tokens reconstructing structure the compiler already knows. Ripwire answers structural questions in tens of milliseconds from a warm index and labels every count it cannot prove is a total. Instead of shipping whole file bodies into context, an agent asks for callers, callees, blast radius, or the tests that need to run, and gets back a ranked list of symbols with paths and line numbers.

Token savings come from replacing full source with signature skeletons. On its own repository, --pack-signatures