diff --git a/.changeset/ci-build-on-pull-request.md b/.changeset/ci-build-on-pull-request.md
new file mode 100644
index 000000000..234bcaf1c
--- /dev/null
+++ b/.changeset/ci-build-on-pull-request.md
@@ -0,0 +1,7 @@
+---
+"worker-comfyui": patch
+---
+
+ci: build base image on every pull request so PR changes are testable before merge
+
+Previously the `Development` workflow only ran on manual `workflow_dispatch`, and `release.yml` only built images after a `chore: version packages` commit landed on `main`. That meant fixes couldn't be deployed and tested on a real Runpod endpoint until they were already merged. With this change, opening or pushing to a PR builds and pushes a `base` image tagged with the branch slug (e.g. `:fix-pin-boto3`), so reviewers can deploy that exact image to a serverless endpoint and verify behavior before approval.
diff --git a/.github/workflows/dev.yml b/.github/workflows/dev.yml
index 741c28c35..56ed9ad20 100644
--- a/.github/workflows/dev.yml
+++ b/.github/workflows/dev.yml
@@ -2,9 +2,12 @@ name: Development
 
 on:
   workflow_dispatch:
-#  push:
-#    branches-ignore:
-#      - main
+  pull_request:
+    types: [opened, synchronize, reopened, ready_for_review]
+    paths-ignore:
+      - "**.md"
+      - "docs/**"
+      - ".changeset/**"
 
 jobs:
   dev:
@@ -42,7 +45,11 @@ jobs:
           echo "DOCKERHUB_REPO=${{ vars.DOCKERHUB_REPO }}" >> $GITHUB_ENV
           echo "DOCKERHUB_IMG=${{ vars.DOCKERHUB_IMG }}" >> $GITHUB_ENV
           echo "HUGGINGFACE_ACCESS_TOKEN=${{ secrets.HUGGINGFACE_ACCESS_TOKEN }}" >> $GITHUB_ENV
-          echo "RELEASE_VERSION=${GITHUB_REF##refs/heads/}" | sed 's/\//-/g' >> $GITHUB_ENV
+          # On pull_request: GITHUB_HEAD_REF is the source branch (e.g. fix/foo).
+          # On workflow_dispatch / push: fall back to the ref's branch name.
+          BRANCH="${GITHUB_HEAD_REF:-${GITHUB_REF##refs/heads/}}"
+          BRANCH_SLUG=$(echo "$BRANCH" | sed 's/[^a-zA-Z0-9._-]/-/g')
+          echo "RELEASE_VERSION=${BRANCH_SLUG}" >> $GITHUB_ENV
 
       - name: Build and push the base image to Docker Hub
         uses: docker/bake-action@v2