$schema: https://json-schema.org/draft/2020-12/schema
$id: https://api-evangelist.com/schemas/avro/avro-schema.json
title: Apache Avro Schema
description: >-
  JSON Schema for validating Apache Avro schema definitions. Avro schemas are
  defined in JSON and support primitive types, complex types (records, enums,
  arrays, maps, unions, fixed), and logical types.
oneOf:
  - $ref: '#/$defs/NamedType'
  - $ref: '#/$defs/PrimitiveType'
  - $ref: '#/$defs/ArrayType'
  - $ref: '#/$defs/MapType'
  - $ref: '#/$defs/UnionType'
  - type: string
    description: Reference to a previously defined named type or a primitive type name
$defs:
  PrimitiveType:
    type: string
    description: Avro primitive type names
    enum:
      - 'null'
      - boolean
      - int
      - long
      - float
      - double
      - bytes
      - string
  NamedType:
    oneOf:
      - $ref: '#/$defs/RecordType'
      - $ref: '#/$defs/EnumType'
      - $ref: '#/$defs/FixedType'
  RecordType:
    type: object
    description: >-
      An Avro record type, analogous to a struct. Contains a list of named
      fields, each with its own type.
    required:
      - type
      - name
      - fields
    properties:
      type:
        type: string
        const: record
      name:
        type: string
        description: Name of the record (must be a valid Avro name)
        pattern: '^[A-Za-z_][A-Za-z0-9_]*$'
      namespace:
        type: string
        description: Namespace qualifier, similar to a package name
      doc:
        type: string
        description: Documentation string for the record
      aliases:
        type: array
        description: Alternate names for this record (for schema evolution)
        items:
          type: string
      fields:
        type: array
        description: List of fields in the record
        items:
          $ref: '#/$defs/Field'
  Field:
    type: object
    description: A field within an Avro record
    required:
      - name
      - type
    properties:
      name:
        type: string
        description: Name of the field
        pattern: '^[A-Za-z_][A-Za-z0-9_]*$'
      type:
        description: >-
          The field's type. Can be a primitive type name, a complex type
          definition, a union (array), or a reference to a named type.
        oneOf:
          - $ref: '#/$defs/PrimitiveType'
          - $ref: '#/$defs/RecordType'
          - $ref: '#/$defs/EnumType'
          - $ref: '#/$defs/FixedType'
          - $ref: '#/$defs/ArrayType'
          - $ref: '#/$defs/MapType'
          - $ref: '#/$defs/UnionType'
          - type: string
            description: Reference to a named type
      doc:
        type: string
        description: Documentation for the field
      default:
        description: >-
          Default value for the field. Must match the field's type. For unions,
          the default must match the first type in the union.
      order:
        type: string
        description: Sort order for the field when used in sorting
        enum:
          - ascending
          - descending
          - ignore
      aliases:
        type: array
        description: Alternate names for this field (for schema evolution)
        items:
          type: string
      logicalType:
        type: string
        description: Logical type annotation
        enum:
          - date
          - time-millis
          - time-micros
          - timestamp-millis
          - timestamp-micros
          - local-timestamp-millis
          - local-timestamp-micros
          - duration
          - decimal
          - uuid
  EnumType:
    type: object
    description: >-
      An Avro enum type with a fixed set of symbol values.
    required:
      - type
      - name
      - symbols
    properties:
      type:
        type: string
        const: enum
      name:
        type: string
        pattern: '^[A-Za-z_][A-Za-z0-9_]*$'
      namespace:
        type: string
      doc:
        type: string
      aliases:
        type: array
        items:
          type: string
      symbols:
        type: array
        description: >-
          List of symbol names defining the allowed values. Each must be unique
          and a valid Avro name.
        items:
          type: string
          pattern: '^[A-Za-z_][A-Za-z0-9_]*$'
        minItems: 1
        uniqueItems: true
      default:
        type: string
        description: Default symbol value for schema evolution
  FixedType:
    type: object
    description: >-
      An Avro fixed type representing a fixed number of bytes.
    required:
      - type
      - name
      - size
    properties:
      type:
        type: string
        const: fixed
      name:
        type: string
        pattern: '^[A-Za-z_][A-Za-z0-9_]*$'
      namespace:
        type: string
      doc:
        type: string
      aliases:
        type: array
        items:
          type: string
      size:
        type: integer
        description: Number of bytes per value
        minimum: 1
      logicalType:
        type: string
        description: Logical type (e.g., decimal, duration)
        enum:
          - decimal
          - duration
  ArrayType:
    type: object
    description: An Avro array type with a single item type
    required:
      - type
      - items
    properties:
      type:
        type: string
        const: array
      items:
        description: Schema for array elements
        oneOf:
          - $ref: '#/$defs/PrimitiveType'
          - $ref: '#/$defs/RecordType'
          - $ref: '#/$defs/EnumType'
          - $ref: '#/$defs/FixedType'
          - $ref: '#/$defs/ArrayType'
          - $ref: '#/$defs/MapType'
          - $ref: '#/$defs/UnionType'
          - type: string
  MapType:
    type: object
    description: An Avro map type with string keys and a single value type
    required:
      - type
      - values
    properties:
      type:
        type: string
        const: map
      values:
        description: Schema for map values (keys are always strings)
        oneOf:
          - $ref: '#/$defs/PrimitiveType'
          - $ref: '#/$defs/RecordType'
          - $ref: '#/$defs/EnumType'
          - $ref: '#/$defs/FixedType'
          - $ref: '#/$defs/ArrayType'
          - $ref: '#/$defs/MapType'
          - $ref: '#/$defs/UnionType'
          - type: string
  UnionType:
    type: array
    description: >-
      An Avro union type, represented as a JSON array of type definitions.
      Unions may not contain more than one schema with the same type (except
      for named types which use distinct names).
    items:
      oneOf:
        - $ref: '#/$defs/PrimitiveType'
        - $ref: '#/$defs/RecordType'
        - $ref: '#/$defs/EnumType'
        - $ref: '#/$defs/FixedType'
        - $ref: '#/$defs/ArrayType'
        - $ref: '#/$defs/MapType'
        - type: string
    minItems: 1