diff --git a/README.md b/README.md
index 9c094ce..63e15bf 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,8 @@
 
 Connect a JavaScript / Node.js application to [Patchstack](https://patchstack.com) for continuous vulnerability monitoring. Scans your `package-lock.json` and reports installed packages so Patchstack can match them against its vulnerability database and notify you when something needs patching.
 
+For how this repo fits with the wider Patchstack ecosystem (`saas`, `hub`, `patchstack-website`, `patchstack-connect`), see [`patchstack/saas` → `docs/ecosystem.md`](https://github.com/patchstack/saas/blob/main/docs/ecosystem.md).
+
 ## Install prompt (for AI coding tools)
 
 Copy and paste this prompt into any AI coding assistant (Cursor, v0, Bolt, Lovable, Claude Code, etc.):