diff --git a/.github/workflows/builder.yml b/.github/workflows/builder.yml
index cfbc34c8e4..869beb121b 100644
--- a/.github/workflows/builder.yml
+++ b/.github/workflows/builder.yml
@@ -1,16 +1,5 @@
 # Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 name: Build Check (Run npm run build everywhere locally if this fails)
 
@@ -22,21 +11,24 @@ env:
 
 jobs:
   build:
-    name: Run build tasks
+    name: Run build tasks (Node ${{ matrix.node-version }})
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: ['20', '21', '22']
     steps:
-    - uses: actions/checkout@v3
-    - uses: pnpm/action-setup@v3
-    - name: Set up node v20
-      uses: actions/setup-node@v4
-      with:
-        node-version: 20.x
-        cache: pnpm
-    - name: Install dependencies
-      run: pnpm install
-    - name: Run build script
-      run: pnpm build
-    - name: Run js tests
-      run: pnpm test:js
-    - name: Validate working directory is clean
-      run: .github/workflows/scripts/ensure-clean-working-tree.sh
+      - uses: actions/checkout@v3
+      - uses: pnpm/action-setup@v3
+      - name: Set up node v${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: pnpm
+      - name: Install dependencies
+        run: pnpm install
+      - name: Run build script
+        run: pnpm build
+      - name: Run js tests
+        run: pnpm test:js
+      - name: Validate working directory is clean
+        run: .github/workflows/scripts/ensure-clean-working-tree.sh
diff --git a/.github/workflows/bump-cli-version.yml b/.github/workflows/bump-cli-version.yml
index ff59e7548e..275e5e3c93 100644
--- a/.github/workflows/bump-cli-version.yml
+++ b/.github/workflows/bump-cli-version.yml
@@ -1,16 +1,5 @@
 # Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 name: Bump and Tag CLI Version
 
diff --git a/.github/workflows/bump-js-version.yml b/.github/workflows/bump-js-version.yml
index 5386dcb756..3c1c042021 100644
--- a/.github/workflows/bump-js-version.yml
+++ b/.github/workflows/bump-js-version.yml
@@ -1,16 +1,5 @@
 # Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 name: Bump and Tag JS Version
 
diff --git a/.github/workflows/bump-package-version.yml b/.github/workflows/bump-package-version.yml
index 628dbbae20..e1dd3c0bfb 100644
--- a/.github/workflows/bump-package-version.yml
+++ b/.github/workflows/bump-package-version.yml
@@ -1,16 +1,5 @@
 # Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 name: Bump Version for a package
 
diff --git a/.github/workflows/e2e-tests.yml b/.github/workflows/e2e-tests.yml
index 0153a2ff1d..3211582949 100644
--- a/.github/workflows/e2e-tests.yml
+++ b/.github/workflows/e2e-tests.yml
@@ -1,16 +1,5 @@
 # Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 name: Run e2e tests
 
@@ -21,15 +10,18 @@ on:
 
 jobs:
   build:
-    name: Run e2e tests
+    name: Run e2e tests (Node ${{ matrix.node-version }})
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: ['20', '21', '22']
     steps:
       - uses: actions/checkout@v3
       - uses: pnpm/action-setup@v3
-      - name: Set up node v20
+      - name: Set up node v${{ matrix.node-version }}
         uses: actions/setup-node@v4
         with:
-          node-version: 20.x
+          node-version: ${{ matrix.node-version }}
           cache: pnpm
       - name: Install dependencies
         run: pnpm install
diff --git a/.github/workflows/formatter.yml b/.github/workflows/formatter.yml
index 6921fa5fd0..0182ea223b 100644
--- a/.github/workflows/formatter.yml
+++ b/.github/workflows/formatter.yml
@@ -1,16 +1,5 @@
 # Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 name: Formatting Check (Run npm run format locally if this fails)
 
diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index 950feea21b..694048c6ad 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -1,16 +1,5 @@
 # Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 name: Go tests and checks
 
diff --git a/.github/workflows/python.yml b/.github/workflows/python.yml
index 4cb0e98cb2..9c80151080 100644
--- a/.github/workflows/python.yml
+++ b/.github/workflows/python.yml
@@ -13,7 +13,7 @@ jobs:
     strategy:
       matrix:
         python-version:
-          - "3.12"
+          - "3.12" # uv manages versions; this is base.
 
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/release_js_main.yml b/.github/workflows/release_js_main.yml
index 31590b3346..cd2ade76e8 100644
--- a/.github/workflows/release_js_main.yml
+++ b/.github/workflows/release_js_main.yml
@@ -1,16 +1,5 @@
 # Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 name: Release Genkit JS
 
diff --git a/.github/workflows/samples.yml b/.github/workflows/samples.yml
index f44f7588f8..69b6a75443 100644
--- a/.github/workflows/samples.yml
+++ b/.github/workflows/samples.yml
@@ -1,20 +1,9 @@
 # Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 name: Build Samples (only runs if /samples/** is changed)
 
-on: 
+on:
   pull_request:
     paths: samples/**
 
@@ -24,19 +13,22 @@ env:
 
 jobs:
   build:
-    name: Build Samples
+    name: Build Samples (Node ${{ matrix.node-version }})
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: ['20', '21', '22']
     steps:
-    - uses: actions/checkout@v3
-    - uses: pnpm/action-setup@v3
-    - name: Set up node v20
-      uses: actions/setup-node@v4
-      with:
-        node-version: 20.x
-        cache: pnpm
-    - name: Install dependencies
-      run: pnpm install
-    - name: Build Samples
-      run: pnpm build:js-samples
-    - name: Validate working directory is clean
-      run: .github/workflows/scripts/ensure-clean-working-tree.sh
+      - uses: actions/checkout@v3
+      - uses: pnpm/action-setup@v3
+      - name: Set up node v${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: pnpm
+      - name: Install dependencies
+        run: pnpm install
+      - name: Build Samples
+        run: pnpm build:js-samples
+      - name: Validate working directory is clean
+        run: .github/workflows/scripts/ensure-clean-working-tree.sh
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 896d284f7c..35f6244e8b 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -1,16 +1,5 @@
 # Copyright 2024 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
 
 name: Run Tests
 
@@ -24,15 +13,18 @@ jobs:
   build:
     name: Run Tests (just DevUI tests for now)
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: ['20', '21', '22']
     steps:
-    - uses: actions/checkout@v3
-    - uses: pnpm/action-setup@v3
-    - name: Set up node v20
-      uses: actions/setup-node@v4
-      with:
-        node-version: 20.x
-        cache: pnpm
-    - name: Install dependencies and build
-      run: pnpm build:genkit-tools
-    - name: Run tests
-      run: pnpm test:genkit-tools
+      - uses: actions/checkout@v3
+      - uses: pnpm/action-setup@v3
+      - name: Set up node v${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: pnpm
+      - name: Install dependencies and build
+        run: pnpm build:genkit-tools
+      - name: Run tests
+        run: pnpm test:genkit-tools
diff --git a/bin/add_license b/bin/add_license
index e8fdb9a16a..5bc5e78e24 100755
--- a/bin/add_license
+++ b/bin/add_license
@@ -42,6 +42,7 @@ $HOME/go/bin/addlicense \
   -ignore '**/dist/**/*' \
   -ignore '**/node_modules/**/*' \
   -ignore '**/pnpm-lock.yaml' \
+  -ignore '**/py/site/**/*.html' \
   -ignore '.nx/**/*' \
   -ignore '.trunk/**/*' \
   "$TOP_DIR"
diff --git a/bin/check_license b/bin/check_license
index c48621876f..a9f6ec1fbc 100755
--- a/bin/check_license
+++ b/bin/check_license
@@ -45,6 +45,7 @@ $HOME/go/bin/addlicense \
   -ignore '**/dist/**/*' \
   -ignore '**/node_modules/**/*' \
   -ignore '**/pnpm-lock.yaml' \
+  -ignore '**/py/site/**/*.html' \
   -ignore '.nx/**/*' \
   -ignore '.trunk/**/*' \
   "$TOP_DIR"
diff --git a/bin/fmt b/bin/fmt
index 4e92254c76..3415f09be9 100755
--- a/bin/fmt
+++ b/bin/fmt
@@ -39,13 +39,9 @@ fi
 popd
 
 # Format all TypeScript code.
-#
-# TODO: Re-enable once we have biome configured and enabled because that is
-# several times faster and compatible.
-#
-#pushd ${TOP_DIR}
-#pnpm run format
-#if [[ $? -ne 0 ]]; then
-#  exit 1
-#fi
-#popd
+pushd ${TOP_DIR}
+pnpm run format
+if [[ $? -ne 0 ]]; then
+  exit 1
+fi
+popd
diff --git a/bin/setup b/bin/setup
index 2c7ceb3a43..3594a13f8e 100755
--- a/bin/setup
+++ b/bin/setup
@@ -24,7 +24,7 @@ fi
 TOP_DIR=$(git rev-parse --show-toplevel)
 
 PNPM_VERSION="10.2.0"
-NODE_VERSION="23"
+NODE_VERSION="22" # See: https://github.com/firebase/genkit/issues/1995
 NVM_VERSION="0.40.1"
 
 AUDIENCE="eng"
diff --git a/biome.json b/biome.json
index c89309e043..b87d6b7b75 100644
--- a/biome.json
+++ b/biome.json
@@ -31,7 +31,10 @@
       ".nx/**",
       ".trunk/**",
       "bazel-*/**",
+      "genkit-tools/genkit-schema.json",
+      "go/**",
       "node_modules/**",
+      "py/**",
       "third_party/**"
     ]
   },
@@ -46,7 +49,7 @@
   },
   "javascript": {
     "formatter": {
-      "arrowParentheses": "asNeeded",
+      "arrowParentheses": "always",
       "attributePosition": "auto",
       "bracketSpacing": true,
       "jsxQuoteStyle": "double",
diff --git a/captainhook.json b/captainhook.json
index 8f460291d9..2154c2d31c 100644
--- a/captainhook.json
+++ b/captainhook.json
@@ -39,6 +39,9 @@
         {
           "run": "bin/fmt"
         },
+        {
+          "run": "pnpm run format:check"
+        },
         {
           "run": "uv run --directory py ruff check --fix ."
         },
@@ -79,6 +82,9 @@
         {
           "run": "bin/fmt"
         },
+        {
+          "run": "pnpm run format:check"
+        },
         {
           "run": "uv run --directory py ruff check --fix ."
         },
diff --git a/package.json b/package.json
index fb14278ec8..b5111ddd6b 100644
--- a/package.json
+++ b/package.json
@@ -6,7 +6,9 @@
     "setup": "npm-run-all pnpm-install-js pnpm-install-genkit-tools build link-genkit-cli",
     "format": "(prettier . --write) && (tsx scripts/copyright.ts)",
     "format:check": "(prettier . --check) && (tsx scripts/copyright.ts --check)",
-    "format:todo": "pnpm dlx @biomejs/biome format --write .",
+    "format:biome": "pnpm dlx @biomejs/biome check --formatter-enabled=true --linter-enabled=false --organize-imports-enabled=true --fix . && bin/add_license",
+    "lint:biome": "pnpm dlx @biomejs/biome lint --fix . && bin/add_license",
+    "format:biome-check": "pnpm dlx @biomejs/biome ci --linter-enabled=false --formatter-enabled=true --organize-imports-enabled=false . && bin/check_license",
     "build": "pnpm build:js && pnpm build:genkit-tools",
     "build:js": "cd js && pnpm i && pnpm build",
     "build:genkit-tools": "cd genkit-tools && pnpm i && pnpm build",