Purpose
You generate or update the skill registry — a catalog of all available skills with compact rules (pre-digested, 5-15 line summaries) that any delegator injects directly into sub-agent prompts. Sub-agents do NOT read the registry or individual SKILL.md files — they receive compact rules pre-resolved in their launch prompt.
This is the foundation of the Skill Resolver Protocol (see _shared/skill-resolver.md). The registry is built ONCE (expensive), then read cheaply at every delegation.
When to Run
- After installing or removing skills
- After setting up a new project
- When the user explicitly asks to update the registry
- As part of
sdd-init(it calls this same logic)
What to Do
Step 1: Scan User Skills
- Glob for
*/SKILL.mdfiles across ALL known skill directories. Check every path below — scan ALL that exist, not just the first match: User-level (global skills): Project-level (workspace skills):
- ~/.claude/skills/ — Claude Code - ~/.config/opencode/skills/ — OpenCode - ~/.gemini/skills/ — Gemini CLI - ~/.cursor/skills/ — Cursor - ~/.copilot/skills/ — VS Code Copilot - The parent directory of this skill file (catch-all for any tool) - {project-root}/.claude/skills/ — Claude Code - {project-root}/.gemini/skills/ — Gemini CLI - {project-root}/.agent/skills/ — Antigravity (workspace) - {project-root}/skills/ — Generic
- **SKIP
sdd-*and_shared** — those are SDD workflow skills, not coding/task skills - Also SKIP
skill-registry— that's this skill - Deduplicate — if the same skill name appears in multiple locations, keep the project-level version (more specific). If both are user-level, keep the first found.
- For each skill found, read the full SKILL.md (if a SKILL.md exceeds 200 lines, focus on the frontmatter and Critical Patterns / Rules sections only) to extract:
- name field (from frontmatter) - description field → extract the trigger text (after "Trigger:" in the description) - Compact rules — the actionable patterns and constraints (see Step 1b)
- Build a table of: Trigger | Skill Name | Full Path
Step 1b: Generate Compact Rules
For each skill found in Step 1, generate a compact rules block (5-15 lines max) containing ONLY:
- Actionable rules and constraints ("do X", "never Y", "prefer Z over W")
- Key patterns with one-line examples where critical
- Breaking changes or gotchas that would cause bugs if missed
DO NOT include: purpose/motivation, when-to-use, full code examples, installation steps, or anything the sub-agent doesn't need to APPLY the skill.
Format per skill:
### {skill-name}
- Rule 1
- Rule 2
- ...Example — compact rules for a React 19 skill:
### react-19
- No useMemo/useCallback — React Compiler handles memoization automatically
- use() hook for promises/context, replaces useEffect for data fetching
- Server Components by default, add 'use client' only for interactivity/hooks
- ref is a regular prop — no forwardRef needed
- Actions: use useActionState for form mutations, useOptimistic for optimistic UI
- Metadata: export metadata object from page/layout, no <Head> componentThe compact rules are the MOST IMPORTANT output of this skill. They are what sub-agents actually receive. Invest time making them accurate and concise.
Step 2: Scan Project Conventions
- Check the project root for convention files. Look for:
- agents.md or AGENTS.md - CLAUDE.md (only project-level, not ~/.claude/CLAUDE.md) - .cursorrules - GEMINI.md - copilot-instructions.md
- If an index file is found (e.g.,
agents.md,AGENTS.md): READ its contents and extract all referenced file paths. These index files typically list project conventions with paths — extract every referenced path and include it in the registry table alongside the index file itself. - For non-index files (
.cursorrules,CLAUDE.md, etc.): record the file directly. - The final table should include the index file AND all paths it references — zero extra hops for sub-agents.
Step 3: Write the Registry
Build the registry markdown:
# Skill Registry
**Delegator use only.** Any agent that launches sub-agents reads this registry to resolve compact rules, then injects them directly into sub-agent prompts. Sub-agents do NOT read this registry or individual SKILL.md files.
See `_shared/skill-resolver.md` for the full resolution protocol.
## User Skills
| Trigger | Skill | Path |
|---------|-------|------|
| {trigger from frontmatter} | {skill name} | {full path to SKILL.md} |
| ... | ... | ... |
## Compact Rules
Pre-digested rules per skill. Delegators copy matching blocks into sub-agent prompts as `## Project Standards (auto-resolved)`.
### {skill-name-1}
- Rule 1
- Rule 2
- ...
### {skill-name-2}
- Rule 1
- Rule 2
- ...
{repeat for each skill}
## Project Conventions
| File | Path | Notes |
|------|------|-------|
| {index file} | {path} | Index — references files below |
| {referenced file} | {extracted path} | Referenced by {index file} |
| {standalone file} | {path} | |
Read the convention files listed above for project-specific patterns and rules. All referenced paths have been extracted — no need to read index files to discover more.Step 4: Persist the Registry
This step is MANDATORY — do NOT skip it.
A. Always write the file (guaranteed availability):
Create the .atl/ directory in the project root if it doesn't exist, then write:
.atl/skill-registry.mdB. If engram is available, also save to engram (cross-session bonus):
mem_save(
title: "skill-registry",
topic_key: "skill-registry",
type: "config",
project: "{project}",
content: "{registry markdown from Step 3}"
)topic_key ensures upserts — running again updates the same observation.
Step 5: Return Summary
## Skill Registry Updated
**Project**: {project name}
**Location**: .atl/skill-registry.md
**Engram**: {saved / not available}
### User Skills Found
| Skill | Trigger |
|-------|---------|
| {name} | {trigger} |
| ... | ... |
### Project Conventions Found
| File | Path |
|------|------|
| {file} | {path} |
### Next Steps
The orchestrator reads this registry once per session and passes pre-resolved skill paths to sub-agents via their launch prompts.
To update after installing/removing skills, run this again.Rules
- ALWAYS write
.atl/skill-registry.mdregardless of any SDD persistence mode - ALWAYS save to engram if the
mem_savetool is available - SKIP
sdd-*,_shared, andskill-registrydirectories when scanning - Read SKILL.md files (respecting the 200-line guard in Step 1) to generate accurate compact rules — this is a build-time cost, not a runtime cost
- Compact rules MUST be 5-15 lines per skill — concise, actionable, no fluff
- Include ALL convention index files found (not just the first)
- If no skills or conventions are found, write an empty registry (so sub-agents don't waste time searching)
- Add
.atl/to the project's.gitignoreif it exists and.atlis not already listed