diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index 0dcb690..6b5861b 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -60,11 +60,12 @@ You are operating in a multi-repo, documentation-first architecture. You MUST ST
 
 ## Session Setup
 
-**Mandatory reads at session start** — in addition to this `copilot-instructions.md`, the agent MUST load the three workspace skills' `SKILL.md` files:
+**Mandatory reads at session start** — in addition to this `copilot-instructions.md`, the agent MUST load the four workspace skills' `SKILL.md` files:
 
 - `docs-discovery/SKILL.md` — **reactive** (triggers on any domain question — must be ready BEFORE the first domain query arrives)
 - `docs-check/SKILL.md` — **reactive** (triggers at the end of every code-modifying response)
 - `protocol-audit/SKILL.md` — **on-demand** (triggers on explicit "audit protocol" command)
+- `adr-author/SKILL.md` — **on-demand + LLM-suggested** (triggers on explicit planning/design requests, or when the LLM flags an ADR-worthy conversation and the user confirms)
 
 **Path resolution**: if this repo is the canonical protocol host (see `@repo` block below — typically AyCode.Core), the paths are local: `.github/skills/<skill>/SKILL.md`. Otherwise, prefix with this repo's `own-dep-repos` AyCode.Core path (see the `## Shared Agent Skills` section below for explicit paths).
 
@@ -72,7 +73,7 @@ You are operating in a multi-repo, documentation-first architecture. You MUST ST
 
 **Amortization — critical, do NOT re-evaluate per-turn**: the Session Setup cost is measured over the ENTIRE session, not per single turn. A typical session has many turns; the first domain question alone already recoups the investment (alternative — repeated source-code `Grep`/`Read` per turn — costs 10-20K tokens *per turn* with lower output quality). Do NOT flag pre-loaded content as "wasteful" for turns that don't invoke it — the design depends on cross-turn amortization + Rule #3 (no-re-read) + on-demand specificity of Rule #4 (Context Recovery). This amortization is the **central token-economics principle** of the entire protocol stack.
 
-The first response's `[LOADED_DOCS: ...]` prefix must reflect **4 files** (this `copilot-instructions.md` + 3 SKILL.md).
+The first response's `[LOADED_DOCS: ...]` prefix must reflect **5 files** (this `copilot-instructions.md` + 4 SKILL.md).
 
 ## Workspace Dependencies
 # own-dep-repos: "name: path" — paths are relative to this repo root (.github/..)
@@ -90,7 +91,7 @@ The first response's `[LOADED_DOCS: ...]` prefix must reflect **4 files** (this
 
 ## Shared Agent Skills
 
-Skills defined in other repos. **All three are pre-loaded at session start per the `## Session Setup` section above** (mandatory — ensures implicit triggers fire reliably):
+Skills defined in other repos. **All four are pre-loaded at session start per the `## Session Setup` section above** (mandatory — ensures implicit triggers fire reliably):
 
 - **protocol-audit** — Cross-repo consistency audit for `.github/copilot-instructions.md` across all 5 repos.
   Location: `AyCode.Core/.github/skills/protocol-audit/SKILL.md`
@@ -104,6 +105,10 @@ Skills defined in other repos. **All three are pre-loaded at session start per t
   Location: `AyCode.Core/.github/skills/docs-check/SKILL.md`
   **Invoke at the end of every code-modifying response.** Read-only on loaded docs; all patches surface as proposals (Rule #5 approval required).
 
+- **adr-author** — Create Architecture Decision Records (ADRs) for architecturally significant design decisions. Structured interview (context → alternatives → trade-offs → decision → consequences) producing a durable `docs/adr/NNNN-<slug>.md` file (product decisions) or a new `LLMP-DEC-N` row in the protocol decision log (meta-protocol decisions).
+  Location: `AyCode.Core/.github/skills/adr-author/SKILL.md`
+  **Invoke on explicit user request** ("let's plan X", "decide Y vs Z", "design the W module") **or proactively flag** when the conversation looks ADR-worthy (user must confirm — never auto-invoke).
+
 ## Protocol History
 
 Cumulative log of LLM-protocol decisions (rule changes, new skills, structural shifts):