enforce 'yamllint' checks

.github/CODEOWNERS

@@ -19,6 +19,7 @@ container-builder/ @nvidia/cuopt-infra-codeowners
 /.github/                       @nvidia/cuopt-ci-codeowners
 /ci/                            @nvidia/cuopt-ci-codeowners
 /.pre-commit-config.yaml        @nvidia/cuopt-ci-codeowners
+/.yamllint.yaml                 @nvidia/cuopt-ci-codeowners
 
 #agent/infra code owners (overrides .github/ for specific paths)
 /AGENTS.md                           @nvidia/cuopt-infra-codeowners

.github/workflows/pr.yaml

@@ -97,6 +97,7 @@ jobs:
           - '!.github/workflows/trigger-breaking-change-alert.yaml'
           - '!.gitignore'
           - '!.pre-commit-config.yaml'
+          - '!.yamllint.yaml'
           - '!codecov.yml'
           - '!AGENTS.md'
           - '!CHANGELOG.md'
@@ -156,6 +157,7 @@ jobs:
           - '!.github/workflows/trigger-breaking-change-alert.yaml'
           - '!.gitignore'
           - '!.pre-commit-config.yaml'
+          - '!.yamllint.yaml'
           - '!codecov.yml'
           - '!AGENTS.md'
           - '!CONTRIBUTING.md'
@@ -226,6 +228,7 @@ jobs:
           - '!.github/workflows/trigger-breaking-change-alert.yaml'
           - '!.gitignore'
           - '!.pre-commit-config.yaml'
+          - '!.yamllint.yaml'
           - '!codecov.yml'
           - '!AGENTS.md'
           - '!CONTRIBUTING.md'
@@ -293,6 +296,7 @@ jobs:
           - '!.github/workflows/trigger-breaking-change-alert.yaml'
           - '!.gitignore'
           - '!.pre-commit-config.yaml'
+          - '!.yamllint.yaml'
           - '!codecov.yml'
           - '!AGENTS.md'
           - '!CONTRIBUTING.md'

.pre-commit-config.yaml

@@ -60,6 +60,17 @@ repos:
     hooks:
       - id: shellcheck
         args: ["--severity=warning"]
+  - repo: https://github.com/adrienverge/yamllint
+    rev: v1.38.0
+    hooks:
+      - id: yamllint
+        additional_dependencies: [pyyaml]
+        exclude: |
+          (?x)^(
+            [.]clang-format$|
+            conda/environments/.*|
+            ^helmchart/cuopt-server/templates
+          )
   - repo: https://github.com/rapidsai/pre-commit-hooks
     rev: v1.6.0
     hooks:
@@ -133,4 +144,4 @@ repos:
 
 
 default_language_version:
-      python: python3
+  python: python3

.yamllint.yaml

@@ -0,0 +1,37 @@
+# SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+extends: default
+
+rules:
+  anchors:
+    forbid-undeclared-aliases: true
+    forbid-duplicated-anchors: true
+    forbid-unused-anchors: true
+  braces:
+    forbid: false
+    min-spaces-inside: 0
+    # allow 1 space for jinja templating in conda recipes
+    max-spaces-inside: 1
+    min-spaces-inside-empty: -1
+    max-spaces-inside-empty: -1
+  brackets: enable
+  colons:
+    max-spaces-before: 0
+    max-spaces-after: 1
+  commas:
+    max-spaces-before: 0
+    min-spaces-after: 1
+    max-spaces-after: 1
+  comments: disable
+  comments-indentation: disable
+  document-end: disable
+  document-start: disable
+  key-duplicates:
+    forbid-duplicated-merge-keys: true
+  line-length: disable
+  truthy:
+    allowed-values: ['false', 'true']
+    # having problematic value in keys is rare... and also
+    # GitHub Actions' choie of 'on:' triggers this check
+    # ref: https://github.com/adrienverge/yamllint/issues/430
+    check-keys: false

codecov.yml

@@ -2,7 +2,7 @@
 comment: false
 coverage:
   status:
-    project: off
+    project: off  # yamllint disable-line rule:truthy
     patch:
       default:
         target: auto

conda/recipes/cuopt/recipe.yaml

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025-2026, NVIDIA CORPORATION.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 schema_version: 1
 
@@ -26,7 +26,7 @@ build:
   prefix_detection:
     # See https://github.com/rapidsai/build-planning/issues/160
     # Blanket ignore here as there are quite a few shared objects shipped in cuopt
-    ignore_binary_files: True
+    ignore_binary_files: true
   script:
     content: |
       ./build.sh cuopt

conda/recipes/libcuopt/recipe.yaml

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025-2026, NVIDIA CORPORATION.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 schema_version: 1
 
@@ -159,11 +159,11 @@ outputs:
           - libboost
           - libboost_iostreams
     tests:
-    - package_contents:
-        files:
-          - lib/libcuopt.so
-          - bin/cuopt_cli
-          - bin/cuopt_grpc_server
+      - package_contents:
+          files:
+            - lib/libcuopt.so
+            - bin/cuopt_cli
+            - bin/cuopt_grpc_server
     about:
       homepage: ${{ load_from_file("python/cuopt/pyproject.toml").project.urls.Homepage }}
       license: ${{ load_from_file("python/cuopt/pyproject.toml").project.license }}

cpp/src/grpc/codegen/field_registry.yaml

@@ -109,6 +109,9 @@
 # Proto value names: proto_prefix + UPPER_SNAKE(CppName), or just CppName if
 # no prefix.
 #
+
+# yamllint disable rule:indentation
+
 enums:
   pdlp_termination_status:
     domain: solution

dependencies.yaml

@@ -73,14 +73,14 @@ files:
   docs:
     output: none
     includes:
-        - cuda
-        - cuda_version
-        - depends_on_libcuopt
-        - depends_on_cuopt
-        - depends_on_cuopt_server
-        - depends_on_cuopt_sh_client
-        - docs
-        - py_version
+      - cuda
+      - cuda_version
+      - depends_on_libcuopt
+      - depends_on_cuopt
+      - depends_on_cuopt_server
+      - depends_on_cuopt_sh_client
+      - docs
+      - py_version
   py_build_libcuopt:
     output: pyproject
     pyproject_dir: python/libcuopt
@@ -239,8 +239,8 @@ dependencies:
     common:
       - output_types: [conda, requirements, pyproject]
         packages:
-          - &cmake_ver cmake>=4.0
-          - &ninja ninja
+          - cmake>=4.0
+          - ninja
       - output_types: conda
         packages:
           - c-compiler
@@ -473,7 +473,7 @@ dependencies:
     common:
       - output_types: [conda, requirements, pyproject]
         packages:
-          - &cuopt_sh_client_unsuffixed cuopt-sh-client==26.8.*,>=0.0.0a0
+          - cuopt-sh-client==26.8.*,>=0.0.0a0
       - output_types: requirements
         packages:
           # pip recognizes the index as a global option for the requirements.txt file
@@ -805,8 +805,8 @@ dependencies:
           - sphinxcontrib-websupport
           - sphinx-design
           - pip:
-            - swagger-plugin-for-sphinx
-            - nvidia-sphinx-theme
+              - swagger-plugin-for-sphinx
+              - nvidia-sphinx-theme
 
   notebooks:
     common:

docs/cuopt/source/cuopt-server/nim-operator/guide/cuopt-nimservice-full.yaml

@@ -50,13 +50,13 @@ spec:
           - host: cuopt.example.com
             http:
               paths:
-              - backend:
-                  service:
-                    name: cuopt-service
-                    port:
-                      number: 8000
-                path: /
-                pathType: Prefix
+                - backend:
+                    service:
+                      name: cuopt-service
+                      port:
+                        number: 8000
+                  path: /
+                  pathType: Prefix
   metrics:
     enabled: true
     serviceMonitor: