generated: '2026-08-06'
method: searched
source: https://ogen.dev/docs/spec/extensions
sources:
  - https://ogen.dev/docs/spec/extensions
  - https://github.com/ogen-go/ogen/blob/main/jsonschema/parser.go
  - https://github.com/ogen-go/ogen/blob/main/openapi/parser/parse_mediatype.go
  - https://github.com/ogen-go/ogen/blob/main/openapi/parser/parse_path_item.go
  - https://github.com/ogen-go/ogen/blob/main/openapi/parser/parse_parameter.go
  - https://github.com/ogen-go/ogen/blob/main/openapi/parser/parse_security.go
name: ogen OpenAPI specification extensions
description: >-
  The registry of `x-` specification-extension terms ogen reads out of an
  OpenAPI v3 document to steer Go code generation. Six are documented on
  ogen.dev; the remaining six were read directly from the parser sources, which
  is the authoritative list. Each term is a patterned field per the OpenAPI
  Specification Extensions mechanism, so a document carrying them stays valid
  for other tooling.
prefix: x-ogen-
foreign_prefix: x-oapi-codegen-
term_count: 12
terms:
  - term: x-ogen-server-name
    applies_to: Server Object (servers[])
    type: string
    documented: true
    docs: https://ogen.dev/docs/spec/extensions#server-name
    description: >-
      Names a server entry so the generator emits a typed server URL builder
      (e.g. ProductionServer) with validated template variables and enum checks.
  - term: x-ogen-name
    applies_to: Schema Object; Parameter Object
    type: string
    documented: true
    docs: https://ogen.dev/docs/spec/extensions#custom-type-name
    description: >-
      Overrides the generated Go type name for a schema, or the generated
      parameter name. Must be a valid exported Go identifier.
    added: v1.18.0 (parameter naming)
  - term: x-ogen-properties
    applies_to: Schema Object
    type: object
    documented: true
    docs: https://ogen.dev/docs/spec/extensions#custom-field-name
    description: >-
      Per-property overrides for generated struct field names, keyed by the
      JSON property name (e.g. parent -> name: Prev). The JSON tag keeps the
      original wire name.
  - term: x-oapi-codegen-extra-tags
    applies_to: Schema Object (property)
    type: object
    documented: true
    docs: https://ogen.dev/docs/spec/extensions#extra-struct-field-tags
    description: >-
      Extra Go struct field tags emitted on the generated field (gorm, valid,
      db, ...). Named for cross-tool compatibility with oapi-codegen rather
      than under the x-ogen- prefix.
  - term: x-ogen-json-streaming
    applies_to: Media Type Object
    type: boolean
    documented: true
    docs: https://ogen.dev/docs/spec/extensions#streaming-json-encoding
    description: >-
      Decode the body as a stream instead of loading the entire JSON payload
      into memory first.
  - term: x-ogen-operation-group
    applies_to: Path Item Object; Operation Object
    type: string
    documented: true
    docs: https://ogen.dev/docs/spec/extensions#operation-groups
    description: >-
      Groups operations so a separate handler interface is generated per group.
      Set on a path item or on an individual operation.
  - term: x-ogen-type
    applies_to: Schema Object
    type: string
    documented: false
    source: jsonschema/parser.go
    description: Substitutes a custom Go type for the generated schema type.
  - term: x-ogen-time-format
    applies_to: Schema Object (string with a time format)
    type: string
    documented: false
    source: jsonschema/parser.go
    description: Overrides the layout used to encode and decode a time value.
  - term: x-ogen-validate
    applies_to: Schema Object
    type: object
    documented: false
    source: jsonschema/parser.go
    description: >-
      Custom validation directives applied to the generated validator for a
      schema.
  - term: x-ogen-raw-response
    applies_to: Media Type Object
    type: boolean
    documented: false
    source: openapi/parser/parse_mediatype.go
    description: >-
      Hands the response body through raw rather than generating a decoder.
      Takes precedence over x-ogen-sse-event-shape.
  - term: x-ogen-sse-event-shape
    applies_to: Media Type Object (text/event-stream)
    type: string
    documented: false
    source: openapi/parser/parse_mediatype.go
    description: >-
      Selects the Server-Sent Events event shape used by the generated SSE
      client iterator. Ignored when x-ogen-raw-response is set.
  - term: x-ogen-custom-security
    applies_to: Security Scheme Object
    type: boolean
    documented: false
    source: openapi/parser/parse_security.go
    description: >-
      Marks a security scheme as custom so the generated SecuritySource
      interface delegates to caller-supplied handling.
x-evidence:
  fetched: '2026-08-06'
  probes:
    - url: https://ogen.dev/docs/spec/extensions
      http_status: 200
    - url: https://api.github.com/repos/ogen-go/ogen/contents/jsonschema/parser.go
      http_status: 200
    - url: https://api.github.com/repos/ogen-go/ogen/contents/openapi/parser/parse_mediatype.go
      http_status: 200