diff --git a/.github/workflows/container-startup-debug.yml b/.github/workflows/container-startup-debug.yml
new file mode 100644
index 000000000..8450e188a
--- /dev/null
+++ b/.github/workflows/container-startup-debug.yml
@@ -0,0 +1,143 @@
+name: Container startup debug
+
+on:
+  pull_request:
+    branches: [refactor]
+
+jobs:
+  debug:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 25
+    permissions:
+      contents: read
+    env:
+      AWS_ACCESS_KEY_ID: debug
+      AWS_SECRET_ACCESS_KEY: debug
+      AWS_SESSION_TOKEN: debug
+      AWS_REGION: us-east-1
+      AWS_DEFAULT_REGION: us-east-1
+      AWS_EC2_METADATA_DISABLED: "true"
+      AGENTCORE_TELEMETRY_DISABLED: "1"
+
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: actions/checkout@v7
+        with:
+          repository: Hweinstock/agentcore-cli
+          ref: fix/project-dev-full-output
+          path: source
+
+      - uses: oven-sh/setup-bun@v2
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "24"
+
+      - uses: astral-sh/setup-uv@v6
+
+      - working-directory: source
+        run: bun install --frozen-lockfile
+
+      - working-directory: source
+        run: bun run build
+
+      - name: Create one container project and start project dev
+        shell: bash
+        run: |
+          set -uo pipefail
+
+          debug_root="$RUNNER_TEMP/agentcore-container-debug"
+          mkdir -p "$debug_root"
+          cli=(node "$GITHUB_WORKSPACE/source/dist/index.js")
+
+          "${cli[@]}" project create \
+            --name "ctdbg${GITHUB_RUN_ID}" \
+            --template empty \
+            --skip-git \
+            --json \
+            >"$debug_root/create.stdout" \
+            2>"$debug_root/create.stderr"
+          create_status=$?
+          if [ "$create_status" -ne 0 ]; then
+            exit "$create_status"
+          fi
+
+          project_dir="$(node -e 'console.log(JSON.parse(require("fs").readFileSync(process.argv[1], "utf8")).project.path)' "$debug_root/create.stdout")"
+
+          runtime_specs=(
+            "agent_python_minimal|agent-python-minimal"
+            "agent_python_strands|agent-python-strands"
+            "py_strands_container|agent-python-strands-container"
+            "agent_python_langchain|agent-python-langchain"
+            "agent_ts_strands|agent-typescript-strands"
+            "agent_ts_vercel|agent-typescript-vercel"
+            "mcp_python_fastmcp|mcp-python-fastmcp"
+            "a2a_python_strands|a2a-python-strands"
+            "agui_python_strands|agui-python-strands"
+          )
+
+          : >"$debug_root/timing"
+          for spec in "${runtime_specs[@]}"; do
+            IFS="|" read -r runtime_name runtime_template <<<"$spec"
+            echo "$(date --iso-8601=seconds) add $runtime_name" >>"$debug_root/timing"
+            (
+              cd "$project_dir"
+              "${cli[@]}" project add runtime \
+                --name "$runtime_name" \
+                --template "$runtime_template" \
+                --json
+            ) >"$debug_root/add-$runtime_name.stdout" 2>"$debug_root/add-$runtime_name.stderr"
+            add_status=$?
+            echo "$(date --iso-8601=seconds) add $runtime_name exit=$add_status" >>"$debug_root/timing"
+            if [ "$add_status" -ne 0 ]; then
+              exit "$add_status"
+            fi
+          done
+
+          echo "$(date --iso-8601=seconds) project-dev start" >>"$debug_root/timing"
+          set +e
+          (
+            cd "$project_dir"
+            timeout --signal=TERM --kill-after=20s 360s \
+              "${cli[@]}" project dev --mode headless
+          ) >"$debug_root/dev.stdout" 2>"$debug_root/dev.stderr"
+          dev_status=$?
+          echo "$(date --iso-8601=seconds) project-dev exit=$dev_status" >>"$debug_root/timing"
+          echo "$dev_status" >"$debug_root/dev.exit"
+          exit "$dev_status"
+
+      - name: Collect container diagnostics
+        if: always()
+        shell: bash
+        run: |
+          set +e
+          debug_root="$RUNNER_TEMP/agentcore-container-debug"
+
+          for file in timing create.stdout create.stderr dev.stdout dev.stderr dev.exit; do
+            echo "===== $file ====="
+            if [ -f "$debug_root/$file" ]; then
+              sed -n '1,1200p' "$debug_root/$file"
+            else
+              echo "(missing)"
+            fi
+          done
+
+          for file in "$debug_root"/add-*.stdout "$debug_root"/add-*.stderr; do
+            echo "===== ${file##*/} ====="
+            if [ -f "$file" ]; then
+              sed -n '1,80p' "$file"
+            fi
+          done
+
+          echo "===== project spec ====="
+          find "$debug_root" -path '*/agentcore/agentcore.json' -print -exec sed -n '1,240p' {} \;
+
+          echo "===== docker info ====="
+          docker info
+
+          echo "===== docker ps -a ====="
+          docker ps -a
+
+          echo "===== docker images ====="
+          docker images