learnings.md 12 KB


type: learnings_registry entry_prefix: LRN schema: id: LRN-XXX date: YYYY-MM-DD pattern: string (what was observed, abstracted) context: string (where/when it happened - concrete) future_application: string (when to recall this) rules:

  • Capture learnings that apply beyond current task.
  • Abstract from incident — pattern reusable, not one-shot fact.
  • Link to source (commit, file, PR) when possible.
  • Replaces previous LESSONS.md format. Old file empty — no content to migrate. ---

Learnings registry (LRN)

Index

ID Date Pattern Applies to
LRN-001 2026-04-22 rtk shape-compression breaks pipes any pipeline chaining rtk curl/cat/read into jq, python -c, awk
LRN-002 2026-04-23 Moving report-file paths requires grepping bash READS, not just WRITES any refactor that moves a generated file used by a dispatcher
LRN-003 2026-04-27 Claude Code disable* settings use sentinel string "disable", not boolean any change to permissions.defaultMode or related blocker keys
LRN-004 2026-04-27 framer-motion rebranded motion Nov 2024 — different packages per framework any new project recommending animation lib; auditing legacy imports
LRN-005 2026-05-03 claude plugin install does NOT enable — separate claude plugin enable required every plugin installer targeting ALWAYS-ON status
LRN-006 2026-05-03 caveman-shrink (and any MCP middleware proxy) non-functional without upstream wrapper any MCP middleware/proxy package — never claude mcp add it bare

LRN-001 — rtk shape-compression silently breaks downstream parsers

  • Date: 2026-04-22
  • Pattern: when tracking tool (rtk) intercepts stdout and returns schematized/compressed representation instead of raw payload, every downstream parser breaks silently — user (or LLM) never sees rtk's output, only parser error.
  • Context: rtk curl replaces raw JSON output with tokenized version, regardless of TTY vs pipe. Claude Code hooks auto-rewrite curlrtk curl, so behavior impossible to anticipate without knowing hook.
  • Future application: for any tool auto-rewriting standard commands, explicitly verify pipe behavior. Documented workaround: exclude_commands=["curl"] in ~/.config/rtk/config.toml, or rtk proxy. See BLK-001.

LRN-002 — Moving report-file paths requires grepping bash READS, not just WRITES

  • Date: 2026-04-23
  • Pattern: when moving write path of generated file (report, artifact, cache), must also grep places that READ that file — not only those that write it. Dispatchers (orchestrator skills dispatching to agent then parsing result) typically contain bash commands like test -s X.md, grep ... X.md, wc -l X.md — refs invisible if only grep for "write" or "output path".
  • Context: .claude/audits/ refactor (commit 5c5e82c). First pass: updated write paths across 5 skills (seo/geo/harden/validate/code-clean) and 3 agents. User asked for verify-gate. They re-grepped, found 10+ bare bash refs (e.g. test -s HARDEN.md, grep -oE ... VALIDATE.md) missed — dispatchers broken (looking at project root while agent writing to .claude/audits/). Fixed in commit 5c5e82c (bundled with same commit).
  • Future application:
    • Before declaring file-path migration "complete", grep basename (grep -rn "HARDEN\.md") plus full path — catch bare bash usages.
    • If file used in pipelines (test, grep, wc, cat, head), search for those verbs explicitly.
    • Verify-gates save work: one extra round forced exhaustive re-grepping. Without it, two dispatchers shipped broken.

LRN-003 — Claude Code disable* settings use sentinel string "disable", not boolean

  • Date: 2026-04-27
  • Pattern: Claude Code blocker-style settings (disableAutoMode, disableBypassPermissionsMode) use literal string "disable" as sentinel. Key absent = feature available; value "disable" turns blocker on. Any other value (including false, true, null) has no effect — doc explicitly states this.
  • Context: switching permissions.defaultMode to "auto" while disableAutoMode: "disable" still present would have failed at startup ("auto mode unavailable"). Naming disable<Foo>: "disable" reads ambiguously — easy to assume boolean toggle and leave key in place.
  • Future application:
    • Before changing defaultMode, audit matching disable* key in same permissions block. If present with value "disable", remove it.
    • Same logic for bypassPermissions mode and disableBypassPermissionsMode.
    • Don't trust doc's naming — read value semantics. Sentinel strings beat booleans here because harness can distinguish "unset" from "explicitly off" (admin policy).
  • Reference: commit 1421578, doc https://code.claude.com/docs/en/settings.

LRN-004 — framer-motion rebranded motion (Nov 2024) — different packages per framework

  • Date: 2026-04-27
  • Pattern: framer-motion renamed motion November 2024. Rename not cosmetic: bundles React (motion/react), Svelte, vanilla-JS support under single npm package, while Vue gets own parallel package motion-v. Legacy package framer-motion still installs and works but in maintenance mode — recommending it in new framework default locks projects into legacy import paths day one. Detection of "is animation already covered" must include both names plus broader anim ecosystem (gsap, lottie-react, react-spring, popmotion, @formkit/auto-animate) to avoid double-installs.
  • Context: building animation-lib auto-install in /init-project and /onboard. Initial user phrasing "framer-motion" (old name remembered). Picking package name without verifying rename would have shipped legacy imports in every new scaffold.
  • Future application:
    • For React / Next.js / Remix / Astro+React / Svelte: motion (import { motion } from 'motion/react').
    • For Vue 3 / Nuxt: motion-v (separate package, separate API).
    • For React Native: do NOT recommend motion — use react-native-reanimated (motion targets DOM).
    • When auditing existing projects, check both framer-motion and motion keys in package.json deps; treat either as "animation already covered".
    • Before adopting any "industry default" lib in framework, verify canonical package name current — naming churn (rebrand, scope change @org/lib, fork) common in JS land.
  • Reference: helper lib/animation-lib-check.sh, BDR-005.

LRN-005 — claude plugin install does NOT enable — claude plugin enable separate step

  • Date: 2026-05-03
  • Pattern: Claude Code CLI splits "available" from "active" for marketplace plugins. claude plugin install --scope user name@source only copies plugin into ~/.claude/plugins/cache/<marketplace>/<plugin>/<version>/. Does NOT write name@source: true into user's settings.json:enabledPlugins map. Without explicit claude plugin enable name@source, plugin sits dormant — installed but unloaded. Symmetric with claude plugin disable, which keeps cache and only removes enabledPlugins entry.
  • Context: discovered auditing why security-guidance and superpowers were ✘ disabled in claude plugin list despite project's install-plugins.sh summary banner declaring them "ALWAYS ON". Root cause: install_plugin() only ran claude plugin install, never enable. Bug stayed invisible because hardcoded printf "│ ✅ ON : security-guidance rtk superpowers │" in session-start.sh printed same names regardless of actual state — lying banner agreed with lying install.
  • Future application:
    • For any plugin meant ALWAYS ON, follow claude plugin install with claude plugin enable name@source (idempotent — no-op if already enabled).
    • Detect "actually enabled" via enabledPlugins[name@source] === true in settings.json, NOT presence of cache dir. Pattern implemented in lib/detect-plugins.sh:plugin_enabled() (filesystem grep, no subprocess).
    • Any banner / status display claiming plugin on must read state, never hardcode names. Hardcoded labels turn single bug into two co-conspiring bugs masking each other.
  • Reference: commit 2ec7935, lib/detect-plugins.sh:plugin_enabled, install-plugins.sh:enable_plugin().

LRN-006 — caveman-shrink (and any MCP middleware proxy) needs upstream wrapper to function

  • Date: 2026-05-03
  • Pattern: some MCP packages are middleware proxies, not standalone servers. They wrap upstream MCP server and transform its responses (e.g. caveman-shrink compresses prose fields). Running them bare via claude mcp add proxy-name -- npx -y proxy-pkg registers server that errors immediately with "missing upstream command" — every health check fails, and Claude Code reports MCP broken until human intervenes. CLI claude mcp add doesn't validate that configured command launches working stdio MCP, so bad registration silently lands.
  • Context: when adding caveman, upstream installer auto-registers claude mcp add caveman-shrink -- npx -y caveman-shrink and prints "registered. wrap an upstream by editing the mcpServers entry". Following that flow leaves user with permanently failing MCP entry until they realize they must edit ~/.claude.json manually.
  • Future application:

    • For any MCP that is proxy/middleware (read package docs for "upstream", "wraps", "proxy"), register under DERIVED name <proxy>-<upstream> with upstream baked into args. Example for caveman-shrink wrapping filesystem server:

      claude mcp add caveman-shrink-fs --scope user -- \
      npx -y caveman-shrink npx -y @modelcontextprotocol/server-filesystem /path
      
    • Detection of "is this MCP correctly set up?" must look for the derived name (caveman-shrink-*), not the bare proxy name. Bare-name registration is treated as broken.

    • Default install scripts should NOT auto-register middleware MCPs — print the snippet for the user to choose an upstream. See install-plugins.sh STEP 5.5.

  • Reference: commit 9b20b84, lib/detect-plugins.sh:detect_caveman_shrink, install-plugins.sh STEP 5.5 MCP block.

LRN-007 — toggle-external.sh enable missed source-only state

  • Date: 2026-05-06
  • Pattern: lib/toggle-external.sh enable <tool> for npx/external skills (darwin-skill, find-skills, emil-design-eng) handled 2 states only: symlink in skills-disabled/ → move to skills/, or symlink in skills/ → already enabled. Missed 3rd: source dir at ~/.agents/skills/<tool> but no symlink. First-run after make plugin lands here until bash link.sh runs. enable errored not installed — run: make plugin — misleading, plugin already installed.
  • Context: user ran ./lib/toggle-external.sh enable darwin-skill after fresh install. ~/.agents/skills/darwin-skill/ populated by install-plugins.sh STEP 8.5 npx call, but link.sh (separate step) not run, so skills/darwin-skill symlink never created. Fix lib/toggle-external.sh:161-179 — add elif [ -d "$src" ] branch creating symlink direct when source dir present. Error message now show resolved source path.
  • Future application:
    • Any toggle script for tools with separate install + symlink steps must check 3 states: disabled-dir, enabled-dir, source-only. Source-only branch create symlink in place, not fail.
    • Error messages name path checked, not abstract tool name — caller verify install vs symlink state without rereading script.
    • Symmetric pairs (enable/disable) both handle same lifecycle states; missing state in one half = silent dead end.
  • Reference: lib/toggle-external.sh:161-179, link.sh:69-83, install-plugins.sh:598-633 STEP 8.5.