aspens: Skill for Claude Code

You are working on doc-sync, the incremental skill update command (aspens doc sync).

Key Concepts

• Monorepo-aware: getGitRoot(repoPath) resolves the actual git root. projectPrefix (toGitRelative) computes the subdirectory offset. scopeProjectFiles() filters changed files to the project subdirectory. Diffs are fetched from gitRoot but file paths are project-relative.
• Multi-target publish: configuredTargets() reads .aspens.json for all configured targets. chooseSyncSourceTarget() picks the best source (prefers Claude if both exist). LLM generates for the source target; publishFilesForTargets() transforms output for all other configured targets. graphSerialized and repoPath are passed through to the transform context for conditional architecture references and disk-based instructions file loading.
• Backend routing: runLLM() from runner.js dispatches to runClaude() or runCodex() based on config.backend (defaults to source target's id).
• Diff-based flow: Gets git diff HEAD~N..HEAD from git root, scopes changed files to project prefix, then feeds diff plus existing skill contents and graph context to the selected backend.
• Changetype filter (Phase 1): isNoOpDiff() from diff-classifier.js skips the LLM call entirely on lockfile-only diffs and diffs touching zero code-bearing files. LOCK_FILES and CODE_BEARING_EXTS are the source of truth — extend them here, not at call sites.
• Prompt path variables: Passes { skillsDir, skillFilename, instructionsFile, configDir } from source target to loadPrompt() for path substitution in prompts.
• Refresh mode (--refresh): Skips diff entirely. Reviews every skill against the current codebase. Base skill refreshed first, then domain skills in parallel batches of PARALLEL_LIMIT (3). Also refreshes instructions file and reports uncovered domains. Refresh mode runs ensureRootKeyFilesSection before syncSkillsSection so the root file always carries a current Key Files block.
• Deterministic section repair: repairDeterministicSections() runs a no-LLM pass that re-injects ## Skills, ## Behavior, and ## Key Files into the root instructions file from on-disk state. Called from the no-op / "up to date" sync paths so missing-section drift is fixed every invocation. The normal sync flow also runs the same Skills + Behavior + Key Files injection block on the canonical instructions file after the LLM step, so drift gets repaired whether or not the LLM produced an update.
• Graph rebuild on every sync: Calls buildRepoGraph + persistGraphArtifacts (with source target) to keep graph fresh. graphSerialized return value is captured and forwarded to publishFilesForTargets for conditional Codex architecture refs. Graph failure is non-fatal.
• Legacy v0.7 hub-block cleanup: notifyLegacyHubBlockIfPresent() surfaces a one-line notice on the first sync after upgrade when AGENTS.md/AGENTS.md still carries the legacy ## Key Files hub-counts block, so the diff that strips it isn't alarming. regenerateStaleCodeMap() force-rebuilds .claude/code-map.md on no-op syncs when it still carries the legacy **Hub files** block.
• Graceful response handling: After LLM returns, if output has content but no <file> tags, treats it as "no updates needed" with a verbose-only warning. The prompt explicitly requests an empty response when nothing needs updating.
• Graph-aware skill mapping: mapChangesToSkills() checks direct file matches via fileMatchesActivation() (from skill-reader.js) and also whether changed files are imported by files matching a skill's activation block.
• Interactive file picker: When diff exceeds 80k chars and TTY is available, offers multiselect with skill-relevant files pre-selected.
• Prioritized diff: buildPrioritizedDiff() gives skill-relevant files 60k char budget, everything else 20k (80k total). Cuts at diff --git boundaries.
• Token optimization: Affected skills sent in full; non-affected skills send only path + description line.
• Split writes: Direct-write files (.claude/, AGENTS.md, root AGENTS.md) use writeSkillFiles(). Directory-scoped AGENTS.md files (e.g. src/AGENTS.md) use writeTransformedFiles().
• Skill-rules regeneration: After writing, regenerates skill-rules.json via extractRulesFromSkills() — only for targets with supportsHooks: true (Claude). Uses hookTarget from publish targets list.
• findExistingSkills is target-aware: Uses target.skillsDir and target.skillFilename to locate skills for any target.
• Git hook (monorepo-aware): installGitHook() installs at the git root with per-project scoping. Hook uses PROJECT_PATH derived from project-relative offset. Each subproject gets its own labeled hook block (# >>> aspens doc-sync hook (label) >>>) with a unique function name (__aspens_doc_sync_<slug>). Multiple subprojects can coexist in one post-commit hook. Hook skips aspens-only commits scoped to the project prefix. 5-minute per-project cooldown via /tmp/aspens-sync-<hash>.lock; logs to /tmp/aspens-sync-<hash>.log (truncated to last 100 lines past 200). Unlabeled v0.6-era blocks are auto-upgraded on re-install.
• Force writes: doc-sync always calls writeSkillFiles with force: true.