diff --git a/home/claude/memory/MEMORY.md b/home/claude/memory/MEMORY.md
index ebc89c5..d353a62 100644
--- a/home/claude/memory/MEMORY.md
+++ b/home/claude/memory/MEMORY.md
@@ -9,4 +9,5 @@
 - [Review and comments workflow](workflow_review_and_comments.md) — show PR body and non-trivial Jira comments before posting; terse IaC code comments; PR body content rules
 - [Sandbox prompts](feedback_sandbox_prompts.md) — don't prompt for sandbox-disable or routine read-only shell ops; broaden permissions instead
 - [Dev clusters disposable](dev_clusters_disposable.md) — Lyra's dev clusters are recreatable; mutate/break freely, no confirmation needed
+- [Nix shell tooling](nix_shell_tooling.md) — any nixpkgs tool runs ad hoc via `nix run`/`nix shell nixpkgs#<pkg>`; a missing command is never a dead end
 - [SIBO Workabout MX project](sibo_workabout_mx_scanner.md) — RE + barcode-inventory project state; scanner is an OO DYL object (oscanner), blocked on on-device ordinal capture; resume via code/inventory/CONTINUATION.md