yaml
name: ExpressYou
plan: premium
active: trueNotes
Mappings are the YAML equivalent of objects or dictionaries. Keys should be consistent and human readable.
YAML Basics
Core YAML syntax, indentation rules, maps, lists, and practical validation commands for day-one and day-100 YAML workflows.
Export
Copy the compact sheet, download it, or print it.
Download
`D` dense toggle · `C` copy all
Scalars, maps, and sequences
Core YAML building blocks and the examples people search for most.
yaml
features:
- message generator
- fix this message
- screenshot to replyNotes
Sequences are the YAML equivalent of arrays or lists.
yaml
app:
name: ExpressYou
pricing:
monthly: 7.99
yearly: 59.99
tools:
- coach me
- message generatorNotes
Nested indentation controls structure. Spaces matter; tabs should be avoided.
yaml
draft: null
enabled: true
max_retries: 3
price: 7.99Notes
Use plain scalars carefully. YAML has implicit typing rules, so quoting can help avoid ambiguity.
Validate and inspect YAML from the terminal
Practical commands that make YAML easier to work with in local and CI workflows.
bash
yamllint config.yamlNotes
`yamllint` is a standard first pass for catching indentation, trailing spaces, duplicate keys, and other issues.
Parse YAML with Python
Quickly verify that a YAML file loads successfully.
bashANYyamlpythonvalidation
bash
python - <<'PY'
import yaml
with open('config.yaml') as f:
print(yaml.safe_load(f))
PYNotes
Useful when you already have Python and PyYAML available and want a fast sanity check.
bash
yq '.' config.yamlNotes
Great for validating structure and making machine-generated YAML easier to inspect.
Validate Kubernetes YAML client-side
Check whether a manifest parses before applying it.
bashANYyamlkubernetesvalidation
bash
kubectl apply --dry-run=client -f deployment.yamlNotes
This catches many structural issues in Kubernetes manifests before they hit the cluster.
More in YAML
YAML Config and API Patterns
Application config, OpenAPI, environment settings, and interoperability patterns for YAML across modern tooling.
YAML Validation, Linting, and Troubleshooting
Common syntax errors, duplicate keys, parser checks, and validation workflows for debugging YAML faster.
YAML with yq: Query, Edit, and Transform
High-value yq commands for reading, updating, filtering, converting, and merging YAML in local scripts and CI pipelines.
YAML for DevOps, Kubernetes, and CI
Kubernetes manifests, GitHub Actions, Helm, Compose, and YAML-powered automation workflows with practical validation commands.
YAML Multi-Document Streams
Document separators, multi-resource YAML files, and commands for splitting, filtering, and validating streamed YAML.
YAML Anchors, Aliases, and Merge Keys
Reusable YAML patterns using anchors and aliases, with merge examples and commands for expanding and validating resolved config.