rules:

  # ============================================================
  # INFO / METADATA
  # ============================================================

  info-title-required:
    description: API title must be present and non-empty.
    severity: error
    given: $.info
    then:
      field: title
      function: truthy

  info-title-format:
    description: API title should follow the pattern "X API" or "X [Name] API".
    severity: warn
    given: $.info.title
    then:
      function: pattern
      functionOptions:
        match: "^X "

  info-description-required:
    description: API description must be present and meaningful.
    severity: error
    given: $.info
    then:
      field: description
      function: truthy

  info-description-min-length:
    description: API description should be at least 50 characters.
    severity: warn
    given: $.info.description
    then:
      function: length
      functionOptions:
        min: 50

  info-version-required:
    description: API version must be specified.
    severity: error
    given: $.info
    then:
      field: version
      function: truthy

  info-contact-required:
    description: Contact information should be provided.
    severity: warn
    given: $.info
    then:
      field: contact
      function: truthy

  info-license-required:
    description: License information should be provided.
    severity: info
    given: $.info
    then:
      field: license
      function: truthy

  # ============================================================
  # OPENAPI VERSION
  # ============================================================

  openapi-version-3:
    description: OpenAPI version must be 3.0.x.
    severity: error
    given: $
    then:
      field: openapi
      function: pattern
      functionOptions:
        match: "^3\\.0\\."

  # ============================================================
  # SERVERS
  # ============================================================

  servers-defined:
    description: At least one server must be defined.
    severity: error
    given: $
    then:
      field: servers
      function: truthy

  servers-https-only:
    description: Server URLs must use HTTPS.
    severity: error
    given: $.servers[*].url
    then:
      function: pattern
      functionOptions:
        match: "^https://"

  servers-description:
    description: Server entries should have descriptions.
    severity: info
    given: $.servers[*]
    then:
      field: description
      function: truthy

  servers-x-domain:
    description: Server URLs should use api.x.com or ads-api.x.com domains.
    severity: info
    given: $.servers[*].url
    then:
      function: pattern
      functionOptions:
        match: "(api\\.x\\.com|ads-api\\.x\\.com)"

  # ============================================================
  # PATHS — NAMING CONVENTIONS
  # ============================================================

  paths-version-prefix:
    description: Paths should start with a version prefix (e.g., /2/).
    severity: warn
    given: $.paths
    then:
      field: "@key"
      function: pattern
      functionOptions:
        match: "^\\/[0-9]"

  paths-no-trailing-slash:
    description: Paths must not have trailing slashes.
    severity: error
    given: $.paths
    then:
      field: "@key"
      function: pattern
      functionOptions:
        notMatch: "\\/$"

  paths-no-query-strings:
    description: Paths must not contain query strings.
    severity: error
    given: $.paths
    then:
      field: "@key"
      function: pattern
      functionOptions:
        notMatch: "\\?"

  paths-snake-case:
    description: Path segments should use snake_case (the dominant X API convention).
    severity: info
    given: $.paths
    then:
      field: "@key"
      function: pattern
      functionOptions:
        notMatch: "\\/[a-z]+[A-Z]"

  paths-path-params-snake-case:
    description: Path parameters should use snake_case.
    severity: warn
    given: $.paths
    then:
      field: "@key"
      function: pattern
      functionOptions:
        notMatch: "\\{[a-z]+[A-Z]"

  # ============================================================
  # OPERATIONS
  # ============================================================

  operation-summary-required:
    description: Every operation must have a summary.
    severity: warn
    given: $.paths[*][get,post,put,patch,delete]
    then:
      field: summary
      function: truthy

  operation-description-required:
    description: Every operation must have a description.
    severity: error
    given: $.paths[*][get,post,put,patch,delete]
    then:
      field: description
      function: truthy

  operation-operationid-required:
    description: Every operation must have an operationId.
    severity: error
    given: $.paths[*][get,post,put,patch,delete]
    then:
      field: operationId
      function: truthy

  operation-operationid-unique:
    description: Operation IDs must be unique across the API.
    severity: error
    given: $
    then:
      function: oasOpId

  operation-operationid-camelcase:
    description: Operation IDs should use camelCase with verb prefixes (e.g., getTweets, createPost, deleteUser).
    severity: warn
    given: $.paths[*][get,post,put,patch,delete].operationId
    then:
      function: pattern
      functionOptions:
        match: "^[a-z][a-zA-Z0-9]*$"

  operation-tags-required:
    description: Every operation must have at least one tag.
    severity: warn
    given: $.paths[*][get,post,put,patch,delete]
    then:
      field: tags
      function: truthy

  # ============================================================
  # TAGS
  # ============================================================

  tags-defined:
    description: Global tags array should be defined.
    severity: warn
    given: $
    then:
      field: tags
      function: truthy

  tags-title-case:
    description: Tag names should use Title Case (e.g., "Direct Messages", "Community Notes").
    severity: info
    given: $.tags[*].name
    then:
      function: pattern
      functionOptions:
        match: "^[A-Z][a-zA-Z0-9]*(\\s[A-Za-z0-9]+)*$"

  # ============================================================
  # PARAMETERS
  # ============================================================

  parameter-description-required:
    description: All parameters must have a description.
    severity: error
    given: $.paths[*][get,post,put,patch,delete].parameters[*]
    then:
      field: description
      function: truthy

  parameter-snake-case:
    description: Parameter names should use snake_case (the dominant X API convention).
    severity: warn
    given: $.paths[*][get,post,put,patch,delete].parameters[*]
    then:
      field: name
      function: pattern
      functionOptions:
        match: "^[a-z][a-z0-9_]*(\\.[a-z][a-z0-9_]*)*$"

  parameter-schema-type:
    description: Parameters must have a schema with a type defined.
    severity: error
    given: $.paths[*][get,post,put,patch,delete].parameters[*].schema
    then:
      field: type
      function: truthy

  parameter-pagination-max-results:
    description: Pagination limit parameters should be named max_results.
    severity: info
    given: $.paths[*].get.parameters[?(@.in=='query')]
    then:
      field: name
      function: pattern
      functionOptions:
        notMatch: "^(page_size|per_page|limit|count|size)$"

  parameter-pagination-token:
    description: Pagination cursor parameters should use next_token or pagination_token.
    severity: info
    given: $.paths[*].get.parameters[?(@.in=='query')]
    then:
      field: name
      function: pattern
      functionOptions:
        notMatch: "^(cursor|page_token|continuation_token|offset)$"

  parameter-expansions:
    description: Expansion parameters should be named expansions for including related objects.
    severity: info
    given: $.paths[*].get.parameters[?(@.in=='query')]
    then:
      field: name
      function: pattern
      functionOptions:
        notMatch: "^(expand|include|embed)$"

  # ============================================================
  # REQUEST BODIES
  # ============================================================

  request-body-json-content:
    description: Request bodies should use application/json content type.
    severity: warn
    given: $.paths[*][post,put,patch].requestBody.content
    then:
      field: application/json
      function: truthy

  # ============================================================
  # RESPONSES
  # ============================================================

  response-success-required:
    description: Every operation must define a success response (2xx).
    severity: error
    given: $.paths[*][get,post,put,patch,delete].responses
    then:
      function: schema
      functionOptions:
        schema:
          anyOf:
            - required: ["200"]
            - required: ["201"]
            - required: ["204"]

  response-description-required:
    description: All responses must have a description.
    severity: error
    given: $.paths[*][get,post,put,patch,delete].responses[*]
    then:
      field: description
      function: truthy

  response-default-error:
    description: Operations should define a default error response for unexpected errors.
    severity: info
    given: $.paths[*][get,post,put,patch,delete].responses
    then:
      field: default
      function: truthy

  response-success-json:
    description: Success responses should use application/json content type.
    severity: warn
    given: $.paths[*][get,post,put,patch].responses.200.content
    then:
      field: application/json
      function: truthy

  # ============================================================
  # SCHEMAS — PROPERTY NAMING
  # ============================================================

  schema-names-pascalcase:
    description: Schema names should use PascalCase.
    severity: warn
    given: $.components.schemas
    then:
      field: "@key"
      function: pattern
      functionOptions:
        match: "^[A-Z][a-zA-Z0-9]*$"

  schema-type-required:
    description: Schemas should have a type defined.
    severity: warn
    given: $.components.schemas[*]
    then:
      field: type
      function: truthy

  schema-properties-snake-case:
    description: Schema properties should use snake_case (the dominant X API convention).
    severity: info
    given: $.components.schemas[*].properties
    then:
      field: "@key"
      function: pattern
      functionOptions:
        match: "^[a-z][a-z0-9]*(_[a-z0-9]+)*$"

  schema-description-top-level:
    description: Top-level schemas should have a description.
    severity: info
    given: $.components.schemas[*]
    then:
      field: description
      function: truthy

  # ============================================================
  # SECURITY
  # ============================================================

  security-schemes-defined:
    description: Security schemes should be defined in components.
    severity: warn
    given: $.components
    then:
      field: securitySchemes
      function: truthy

  security-bearer-token:
    description: A BearerToken security scheme should be defined for app-only auth.
    severity: info
    given: $.components.securitySchemes
    then:
      field: BearerToken
      function: truthy

  security-oauth2-user:
    description: An OAuth2UserToken security scheme should be defined for user context auth.
    severity: info
    given: $.components.securitySchemes
    then:
      field: OAuth2UserToken
      function: truthy

  security-operation-defined:
    description: Every operation should define its security requirements.
    severity: warn
    given: $.paths[*][get,post,put,patch,delete]
    then:
      field: security
      function: truthy

  # ============================================================
  # HTTP METHOD CONVENTIONS
  # ============================================================

  get-no-request-body:
    description: GET operations must not have a request body.
    severity: error
    given: $.paths[*].get
    then:
      field: requestBody
      function: falsy

  delete-no-request-body:
    description: DELETE operations should not have a request body.
    severity: warn
    given: $.paths[*].delete
    then:
      field: requestBody
      function: falsy

  post-request-body:
    description: POST operations should have a request body.
    severity: info
    given: $.paths[*].post
    then:
      field: requestBody
      function: truthy

  # ============================================================
  # X API SPECIFIC PATTERNS
  # ============================================================

  response-data-wrapper:
    description: Success responses should use a data wrapper object for consistency.
    severity: info
    given: $.paths[*][get,post].responses.200.content.application/json.schema.properties
    then:
      field: data
      function: truthy

  response-errors-array:
    description: Error responses should include an errors array.
    severity: info
    given: $.components.schemas[?(@.properties.errors)]
    then:
      field: properties.errors
      function: truthy

  parameter-fields-dot-notation:
    description: Field selection parameters should use dot notation (e.g., tweet.fields, user.fields, media.fields).
    severity: info
    given: $.paths[*].get.parameters[?(@.name)]
    then:
      field: name
      function: pattern
      functionOptions:
        notMatch: "^(fields|select_fields|include_fields)$"

  # ============================================================
  # GENERAL QUALITY
  # ============================================================

  no-empty-descriptions:
    description: Descriptions must not be empty strings.
    severity: error
    given: "$..description"
    then:
      function: truthy

  external-docs-encouraged:
    description: External documentation link should be provided.
    severity: info
    given: $
    then:
      field: externalDocs
      function: truthy

  deprecated-description:
    description: Deprecated operations should explain the deprecation in their description.
    severity: warn
    given: $.paths[*][get,post,put,patch,delete][?(@.deprecated==true)]
    then:
      field: description
      function: pattern
      functionOptions:
        match: "[Dd]eprecated|[Ss]unset|[Rr]etired|[Rr]eplaced|[Mm]igrat"