yvgude--lean-ctx/rust/LEAN-CTX.md

CRITICAL: ALWAYS use lean-ctx ctx_* tools instead of native equivalents. This is NOT optional.

ACTUALLY EMIT the ctx_* tool call (ctx_compose first) — describing a tool is not calling it.

MANDATORY MAPPING: • Read/cat -> ctx_read(path, mode) • Grep -> ctx_search(pattern, path) • Shell/bash -> ctx_shell(command) • Glob/find -> ctx_glob(pattern) • ls/find -> ctx_tree(path, depth)

NEVER use native Read/Grep/Shell/Glob when a ctx_* equivalent exists. SELF-CORRECT: the moment you reach for one, stop and call the ctx_* tool instead.

Tool selection by intent: • Orient / understand code (call FIRST) -> ctx_compose • Read a file -> ctx_read(path, mode=signatures|map|full); edit after reading -> ctx_patch • Exact symbol -> ctx_search(action=symbol); pattern -> ctx_search; by meaning -> ctx_search(action=semantic) • Files by glob -> ctx_glob; structure -> ctx_tree; callers/impact -> ctx_callgraph • Verify after edits -> ctx_shell(test/build); memory -> ctx_session / ctx_knowledge Semantic questions -> search tools, not whole-file reads: reading more ≠ understanding more.

AGENT LOOP (phase -> tool): • Orient — understand before acting -> ctx_compose • Find — exact symbol by name -> ctx_search(action=symbol) • Read — a file, structurally -> ctx_read(mode=signatures|map) • Locate — a pattern across files -> ctx_search • Trace — callers / callees / blast radius -> ctx_callgraph • Verify — after an edit -> ctx_shell(test/build) + native lints

Anti-patterns — do NOT: • Chain ctx_search -> ctx_read -> ctx_search(action=symbol) — one ctx_compose replaces all three • Use ctx_read(mode=full) for orientation — use mode=signatures • Use ctx_callgraph/ctx_graph for const/static/variable refs — they track call edges and file deps only; use ctx_search instead

NAVIGATION PARADOX: reading more ≠ understanding more. • Semantic question ("where/how is X handled?") -> ctx_search (BM25) + ctx_search(action=semantic) (meaning), not whole-file reads • Hidden architectural deps (who calls this, what breaks) -> ctx_callgraph / ctx_graph — for these only • Navigate structure (signatures, symbols) before reading entire files

PARALLEL: fire independent tool calls in the SAME turn — ctx_compose bundles multiple lookups into one call.

Auto: preload/dedup/compress run in background. ctx_session=memory, ctx_knowledge=facts, ctx_shell raw=true=uncompressed. Full guide: LEAN-CTX.md

RECOVER: compressed output is reversible — never re-read line-by-line. Need full/exact? Read the shown file path with any tool (no MCP), or ctx_read(mode=full|raw=true); [Archived]/tee/firewall → ctx_expand(id=...).

CEP v1: 1.ACT FIRST 2.DELTA ONLY (Fn refs) 3.STRUCTURED (+/-/~) 4.ONE LINE PER ACTION 5.QUALITY ANCHOR

OUTPUT: never echo tool output, no narration comments, show only changed code.

TOOL PREFERENCE (END): ctx_compose>chain ctx_read>Read ctx_shell>Shell ctx_search>Grep ctx_glob>Glob ctx_tree>ls | Edit/Write/Delete=native