state-trace

Bounded working memory for coding agents that need to remember what file failed, what hypothesis was already tried, and what to do next without burning your context window. Exposes typed graph nodes (task, observation, file, error_signature, patch_hunk) and edges (patches_file, supersedes, contradicts) instead of generic entity-relation pairs. Query current_state() to see what's live, failed_hypotheses() to avoid proposing the same fix twice, and retrieve_brief() to get compact file-level context for smaller models. Built on networkx with SQLite+FTS5 cold storage. Beats BM25 and Graphiti on SWE-bench-Verified artifact localization (25% vs 18% vs 10% at rank 1) with 15ms retrieval latency. Mount it via stdio MCP in Claude, Cursor, or any agent loop that needs memory with decay and compression baked in.