{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://api-evangelist.github.io/linting/json-schema/linting-rule-schema.json",
  "title": "Linting Rule",
  "description": "A normalized representation of a single linting rule that can be sourced from Spectral, Vacuum, Redocly CLI, Optic, sweater-comb, Speakeasy, or Postman API Governance. Optimized for cross-tool ruleset analysis, indexing, and re-emission.",
  "type": "object",
  "required": ["id", "severity", "given", "then", "sourceTool"],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Stable identifier for the rule, e.g. `operation-operationId-unique`.",
      "pattern": "^[a-z0-9][a-z0-9._-]*$"
    },
    "description": {
      "type": "string",
      "description": "Human-readable summary of what the rule enforces."
    },
    "message": {
      "type": "string",
      "description": "Message emitted when the rule is violated. Spectral supports `{{error}}`, `{{path}}`, `{{value}}` placeholders; Redocly and Vacuum follow similar conventions."
    },
    "severity": {
      "description": "Importance of a violation. Numeric form matches Spectral: error(0), warn(1), info(2), hint(3). `off` disables a rule inherited from an extended ruleset.",
      "oneOf": [
        { "type": "string", "enum": ["error", "warn", "info", "hint", "off"] },
        { "type": "integer", "minimum": 0, "maximum": 3 }
      ]
    },
    "given": {
      "description": "One or more JSONPath++ (Spectral/Vacuum), where-selector (Redocly), or Optic FactsContext expressions that select the nodes the rule applies to.",
      "oneOf": [
        { "type": "string" },
        { "type": "array", "items": { "type": "string" }, "minItems": 1 }
      ]
    },
    "then": {
      "description": "The assertion(s) to evaluate against each node matched by `given`.",
      "oneOf": [
        { "$ref": "#/$defs/Then" },
        { "type": "array", "items": { "$ref": "#/$defs/Then" }, "minItems": 1 }
      ]
    },
    "target": {
      "type": "string",
      "description": "Optional explicit target name (`info`, `paths`, `operations`, `schemas`, etc.) for tools that key rules to artifact regions rather than JSONPath.",
      "enum": [
        "info",
        "paths",
        "operations",
        "parameters",
        "requestBodies",
        "responses",
        "schemas",
        "headers",
        "securitySchemes",
        "servers",
        "tags",
        "channels",
        "messages",
        "components",
        "document"
      ]
    },
    "when": {
      "type": "object",
      "description": "Optional gating condition (Redocly `where`/`subject.matches`, Spectral `given` qualifier). When present, the rule only fires for nodes that satisfy the condition.",
      "properties": {
        "subject": { "type": "string" },
        "matches": { "type": "string" },
        "property": { "type": "string" },
        "value": {}
      },
      "additionalProperties": true
    },
    "formats": {
      "type": "array",
      "description": "Spec formats the rule is scoped to. Tools differ on identifiers; this schema accepts the union.",
      "items": {
        "type": "string",
        "enum": [
          "oas2",
          "oas3",
          "oas3_0",
          "oas3_1",
          "asyncapi2",
          "asyncapi3",
          "arazzo1",
          "json-schema-draft-04",
          "json-schema-draft-06",
          "json-schema-draft-07",
          "json-schema-2019-09",
          "json-schema-2020-12",
          "open-rpc"
        ]
      }
    },
    "recommended": {
      "type": "boolean",
      "description": "Whether the rule is included in the tool's `recommended` profile."
    },
    "tags": {
      "type": "array",
      "description": "Free-form classification tags (e.g. `Security`, `Naming`, `Documentation`, `OWASP`).",
      "items": { "type": "string" }
    },
    "sourceTool": {
      "type": "string",
      "description": "The linting tool the rule originated in.",
      "enum": [
        "spectral",
        "vacuum",
        "redocly-cli",
        "optic",
        "sweater-comb",
        "speakeasy",
        "postman",
        "apicurio",
        "apimetrics",
        "custom"
      ]
    },
    "sourceUrl": {
      "type": "string",
      "format": "uri",
      "description": "Link to the canonical definition of the rule (ruleset file, docs page, or registry entry)."
    },
    "documentationUrl": {
      "type": "string",
      "format": "uri",
      "description": "Link to human-readable documentation for the rule."
    }
  },
  "$defs": {
    "Then": {
      "type": "object",
      "required": ["function"],
      "additionalProperties": false,
      "properties": {
        "field": {
          "type": "string",
          "description": "Optional sub-field of the matched node to apply the function to."
        },
        "function": {
          "type": "string",
          "description": "Name of the built-in or custom function evaluating the assertion.",
          "examples": [
            "truthy",
            "falsy",
            "defined",
            "undefined",
            "pattern",
            "enumeration",
            "length",
            "alphabetical",
            "casing",
            "xor",
            "schema",
            "unreferencedReusableObject",
            "typedEnum"
          ]
        },
        "functionOptions": {
          "type": "object",
          "description": "Options passed to the function (e.g. `match`/`notMatch` for `pattern`, `type` for `casing`, `min`/`max` for `length`).",
          "additionalProperties": true
        }
      }
    }
  }
}