diff --git a/.tangled/workflows/check.yml b/.tangled/workflows/check.yml
index e436130..8e3e5ec 100644
--- a/.tangled/workflows/check.yml
+++ b/.tangled/workflows/check.yml
@@ -21,5 +21,37 @@ steps:
   - name: "Initialize devenv"
     command: devenv shell true
 
+  - name: "Prime Dagger base image cache"
+    command: |
+      devenv shell -- bash -c '
+        set -euo pipefail
+        export DAGGER_NO_NAG=1
+        export DOCKER_BUILDKIT=1
+        BASE_HASH="$(sha256sum \
+          application/Dockerfile \
+          application/frankenphp/conf.d/10-app.ini \
+          application/frankenphp/docker-entrypoint.sh \
+          application/frankenphp/Caddyfile \
+          | sha256sum | cut -c1-16)"
+        BASE_REF="${DAGGER_PHP_BASE_REF:-ttl.sh/rssbase-application-dagger-frankenphp-base-${BASE_HASH}:24h}"
+        BASE_CACHE_REF="${DAGGER_PHP_BASE_CACHE_REF:-ttl.sh/rssbase-application-dagger-frankenphp-base-build-cache:24h}"
+
+        if docker buildx imagetools inspect "${BASE_REF}" >/dev/null 2>&1; then
+          echo "Using cached Dagger base image: ${BASE_REF}"
+        else
+          echo "Building and publishing Dagger base image: ${BASE_REF}"
+          docker buildx create --use --name rssbase-ci-builder >/dev/null 2>&1 || docker buildx use rssbase-ci-builder
+          docker buildx inspect --bootstrap
+          docker buildx build application \
+            --target frankenphp_base \
+            --tag "${BASE_REF}" \
+            --cache-from "type=registry,ref=${BASE_CACHE_REF}" \
+            --cache-to "type=registry,ref=${BASE_CACHE_REF},mode=max" \
+            --push
+        fi
+
+        dagger settings --env ci application phpBaseImageRef "${BASE_REF}"
+      '
+
   - name: "Run checks"
-    command: DAGGER_NO_NAG=1 devenv shell dagger check
+    command: DAGGER_NO_NAG=1 devenv shell dagger --env ci check
diff --git a/application/.dagger/main.dang b/application/.dagger/main.dang
index a8adbc8..9679cfb 100644
--- a/application/.dagger/main.dang
+++ b/application/.dagger/main.dang
@@ -2,15 +2,34 @@
 Dagger workflows for rssbase.io/application.
 """
 type Application {
-  let source: Directory! @defaultPath(path: "/application") @ignorePatterns(patterns: [
-    ".dagger",
-    "var",
-    "vendor",
-  ])
+  pub source: Directory!
+  pub phpBaseImageRef: String!
+
+  new(
+    ws: Workspace!,
+    """
+    Optional prebuilt frankenphp_base image to use instead of building the Dockerfile in Dagger.
+    Useful in ephemeral CI where the Dagger engine cache starts empty.
+    """
+    phpBaseImageRef: String! = "",
+  ) {
+    self.source = ws.directory("/application", exclude: [
+      ".dagger",
+      "var",
+      "vendor",
+    ])
+    self.phpBaseImageRef = phpBaseImageRef
+    self
+  }
 
   let phpBase: Container! {
-    source
-      .dockerBuild(target: "frankenphp_base")
+    let base = if (phpBaseImageRef != "") {
+      container.from(phpBaseImageRef)
+    } else {
+      source.dockerBuild(target: "frankenphp_base")
+    }
+
+    base
       .withDirectory("/app", source)
       .withWorkdir("/app")
       .withMountedCache("/tmp/composer-cache", cacheVolume("composer-cache"))