diff --git a/README.md b/README.md
index c2e86e3..48d2029 100644
--- a/README.md
+++ b/README.md
@@ -81,6 +81,8 @@ cd backend && go test -tags "test,dev" -count=1 -race -timeout 480s ./...  # rac
 cd backend && go test -tags "test,dev" -count=10 -parallel 8 ./...  # thorough verification (~2-3min)
 ```
 
+CI caches Go modules (`~/go/pkg/mod`) and npm dependencies (`~/.npm`, `node_modules`) via `actions/cache` — keyed on `go.sum` and `package-lock.json` respectively. Cache is served by Gitea's built-in cache server at `git.popertots.com`.
+
 ## Full Documentation
 
 Detailed architecture, schema, admin workflows, user journeys, and backlog in [obsidian/Crussell/](obsidian/Crussell/).