diff --git a/docs/WEB_AI_FAST_ROADMAP.md b/docs/WEB_AI_FAST_ROADMAP.md
index 7dadde2..612ee24 100644
--- a/docs/WEB_AI_FAST_ROADMAP.md
+++ b/docs/WEB_AI_FAST_ROADMAP.md
@@ -5,7 +5,7 @@
 **Repo:** `learning_ai_notes`  
 **Scope:** **Web app** (`web/`) first; calls out backend/platform dependencies explicitly.
 
-**Companion docs:** [`AGENT_TASK_ROADMAP.md`](./AGENT_TASK_ROADMAP.md) (agent execution / CI / platform blockers), [`roadmaps/03_WEB_ROADMAP.md`](./roadmaps/03_WEB_ROADMAP.md) (historical web phases), [`roadmaps/05_MCP_AGENT_ROADMAP.md`](./roadmaps/05_MCP_AGENT_ROADMAP.md) (MCP tooling).
+**Companion docs:** [`PRD.md`](./PRD.md), [`AGENT_TASK_ROADMAP.md`](./AGENT_TASK_ROADMAP.md) (agent execution / CI / platform blockers), [`roadmaps/03_WEB_ROADMAP.md`](./roadmaps/03_WEB_ROADMAP.md) (historical web phases), [`roadmaps/05_MCP_AGENT_ROADMAP.md`](./roadmaps/05_MCP_AGENT_ROADMAP.md) (MCP tooling).
 
 ---
 
@@ -226,4 +226,4 @@ cd web && pnpm exec playwright test   # when E2E touched
 
 | Date | Change |
 |------|--------|
-| 2026-03-31 | Initial roadmap; task-summary table fix, unnumbered meta sections, maintenance note for checkboxes. |
+| 2026-03-31 | Initial roadmap (table fix, meta sections, checkbox maintenance note); companion link to PRD.md. |