> ## Documentation Index
> Fetch the complete documentation index at: https://docs.base39.com.br/llms.txt
> Use this file to discover all available pages before exploring further.

# Create a mapper rule



## OpenAPI

````yaml /api-reference/openapi.json post /v2/admin/datasets/{slug}/rules
openapi: 3.1.0
info:
  title: Base39 API
  description: Base39 API
  version: 1.0.0
  contact:
    name: Base39 Team
    url: https://base39.com.br
    email: suporte@base39.com.br
  termsOfService: https://base39.com.br/termos
  license:
    name: Proprietary
    url: https://base39.com.br/termos
servers:
  - url: http://localhost:3000
    description: Local
  - url: https://api.dev.base39.cloud
    description: Development
  - url: https://api.base39.com.br
    description: Production
security:
  - OAuth2: []
tags:
  - name: pages
    description: Profiles and reports pages
  - name: pipelines
    description: Pipeline boards (kanban) of pages
  - name: blocks
    description: Blocks operations
  - name: search
    description: Search across content
  - name: targets
    description: Lookup targets via datasets
  - name: CognitoTriggers
    description: Cognito triggers
paths:
  /v2/admin/datasets/{slug}/rules:
    post:
      tags:
        - admin
      summary: Create a mapper rule
      operationId: datasets_admin_create_rule
      parameters:
        - name: slug
          required: true
          in: path
          schema:
            type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateMapperRuleDto'
      responses:
        '201':
          description: ''
components:
  schemas:
    CreateMapperRuleDto:
      type: object
      properties:
        name:
          type: string
          example: extract subject person from reports[0].registration
        targetEntity:
          type: string
          enum:
            - lawsuit
            - lawsuit_party
            - lawsuit_activity
            - person
            - company
            - company_shareholder
        expression:
          type: string
          description: JSONata expression returning array<observation>
        priority:
          type: number
          default: 0
        enabled:
          type: boolean
          default: true
        notes:
          type: string
      required:
        - name
        - targetEntity
        - expression
  securitySchemes:
    OAuth2:
      type: oauth2
      flows:
        authorizationCode:
          authorizationUrl: https://id.local.base39.cloud/oauth2/authorize
          tokenUrl: https://id.local.base39.cloud/oauth2/token
          scopes:
            profile: Read user profile
            email: Read user email
            openid: OpenID authentication
      description: OAuth2 Authorization Code flow

````