YAML duplicate key checker
Open YAML duplicate key checker on Happytails.ai. This view has the same page content and links, with explicit tool capabilities. Read the processing notes before using a tool.
Tool capabilities
{
"id": "yaml-duplicate-key-checker",
"category": "data-tools",
"built": true,
"requirements": "Up to 100 documents, 50,000 parsed nodes and 64 nesting levels. Diagnostic reports omit source text and key values. No application schema is checked. Runs on your device with no configuration, repository or credential lookups. Up to 1,000,000 input characters and 4,000,000 characters per output file.",
"implementation": {
"fields": [],
"live": true,
"presentation": "metrics",
"note": "Up to 100 YAML documents, 50,000 parsed nodes and 64 nesting levels. Diagnostic reports omit source text and key values. No application schema is checked. Find duplicate scalar mapping keys and show their document, line and column. String keys and numeric keys remain distinct types. Collection-valued keys and unresolved tags are reported as unsupported instead of receiving a false all-clear. Includes up to 500 diagnostics with an omitted count. Runs on your device. No remote configuration, repository or credentials are queried. Up to 1,000,000 input characters; output files are limited to 4,000,000 characters each.",
"experience": {
"automatic": true,
"single": false,
"inputMaxLength": 1000000,
"inputMode": "text",
"label": "Configuration text",
"placeholder": "service:\n timeout: 30\n timeout: 60\n",
"help": "Paste text to process locally. Review the supported syntax and the result before downloading. Results update as you type. Up to 1,000,000 characters.",
"helpParts": [
"Paste text to process locally. Review the supported syntax and the result before downloading.",
"Results update as you type.",
"Up to 1,000,000 characters."
],
"action": null
},
"mode": "automatic",
"interactive": false
},
"execution": "Browser interface",
"api": null,
"browser_agent": {
"supported": true,
"name": "run_current_tool",
"discovery": "WebMCP on the human page in a supporting browser",
"verification": "See audit/API-AUDIT.md; availability is not verification"
}
}Page guide
Find duplicate YAML mapping keys with document, line and column locations. Check nested maps without silently overwriting earlier entries.
How to use YAML duplicate key checker
- Paste the YAML configuration.
- Review each issue’s document and source location.
- Correct duplicates and rerun, then download the diagnostic report.
Useful next steps
Find duplicates in their own mapping
Paste one or more YAML documents. A repeated scalar key in the same mapping is flagged, including nested maps and scalar alias keys. The same key in separate maps is allowed. Numeric and quoted string keys remain distinct types.
Get locations without exposing configuration values
The report contains fixed issue messages and document, line and column numbers. It does not repeat keys, values or neighboring source lines. Up to 500 diagnostics are listed with a count of omitted issues.
Distinguish no duplicates from unsupported input
The checker also reports syntax errors and unresolved aliases. Collection-valued mapping keys and unknown tags are explicitly unsupported rather than receiving an all-clear. It does not verify application-specific settings or merge-key precedence.