Format OpenAPI

Format an OpenAPI document with stable indentation and readable nested schemas.

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ToolOpenAPI Formatter
Input
Output
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How it works

The document is parsed into paths, operations, components, schemas, and security objects, then serialized with stable indentation and key ordering. References and descriptions remain intact; formatting does not validate or resolve the contract.

  • Stable ordering reduces review noise.
  • Indentation exposes nested response structures.

Worked example

Format Minified OpenAPI Spec
Pretty-print a minified OpenAPI 3.0 spec with proper indentation
Input
											{"openapi":"3.0.3","info":{"title":"Pet Store","version":"1.0.0"},"paths":{"/pets":{"get":{"summary":"List pets","responses":{"200":{"description":"OK"}}}}}}
Output
												{
  "openapi": "3.0.3",
  "info": {
    "title": "Pet Store",
    "version": "1.0.0"
  },
  "paths": {
    "/pets": {
      "get": {
        "summary": "List pets",
        "responses": {
          "200": {
            "description": "OK"
          }
        }
      }
    }
  }
}

When to use this

API pull requests, documentation builds, and gateway repositories format specs.

Edge cases

  • YAML anchors may not map to OpenAPI references.
  • Key ordering can change text without changing meaning.
  • An invalid $ref remains invalid after formatting.

References