Beyond RAG: A Relational Context Engine That Cuts Token Burn — Unblocked

Vector search can't answer "which PRs did I merge last week?" A relational context engine can, and it cuts token burn along the way. Peter Werry, founding engineer at Unblocked, explains what a context engine is and why coding agents need more than code search: the PRs, Slack threads and incident history that explain why the code is the way it is. He shows Claude sessions with and without that context, including one with about a 50% drop in cost and one that traced a regression to a model switch. Then he builds Unblocked's open-source document query engine step by step: automatic schema discovery, identity resolution across systems, query validation that blocks dangerous operators, retries that feed errors back to the model, and full-text search. He closes with the open-source context engine simulator for testing whether pre-gathered context helps your agents. In this talk: • What a context engine is, and how it lowers cost on real agent sessions • Why vector stores can't answer structural questions about your work • Turning plain-English questions into safe, validated database queries • Schema discovery, identity resolution, retries and full-text search SPEAKER Peter Werry, Founding Engineer, Unblocked LINKS Unblocked: https://getunblocked.com Document query engine (GitHub): https://github.com/unblocked/document-query-engine Unblocked on X: https://x.com/get_unblocked CHAPTERS 0:00 Intro 0:52 Agenda 2:22 Demo: agents with and without context 4:17 Half the cost 4:57 Tracing a model regression 6:17 Let's build 7:11 Questions vector search can't answer 8:21 The hard part: scaffolding 9:46 The document query engine 10:31 Automatic schema discovery 12:26 Identity resolution 13:45 Validating queries 15:50 Retries 16:35 Full-text search 18:30 Context engine simulator Recorded at the AI Engineer World's Fair 2026 in San Francisco. Subscribe for more talks from the engineers building with AI. AI Engineer: https://ai.engineer YouTube: https://www.youtube.com/@aiDotEngineer X: https://x.com/aiDotEngineer LinkedIn: https://www.linkedin.com/company/aidotengineer/ #ContextEngineering #RAG #AIEngineer