groups:
  - id: registry.http
    prefix: http
    type: attribute_group
    brief: 'This document defines semantic convention attributes in the HTTP namespace.'
    attributes:
      - id: request.body.size
        type: int
        brief: >
          The size of the request payload body in bytes. This is the number of bytes transferred excluding headers and
          is often, but not always, present as the [Content-Length](https://www.rfc-editor.org/rfc/rfc9110.html#field.content-length)
          header. For requests using transport encoding, this should be the compressed size.
        examples: 3495
        stability: experimental  # this should not be marked stable with other HTTP attributes
      - id: request.header
        stability: stable
        type: template[string[]]
        brief: >
          HTTP request headers, `<key>` being the normalized HTTP Header name (lowercase), the value being the header values.
        note: >
          Instrumentations SHOULD require an explicit configuration of which headers are to be captured.
          Including all request headers can be a security risk - explicit configuration helps avoid leaking sensitive information.

          The `User-Agent` header is already captured in the `user_agent.original` attribute.
          Users MAY explicitly configure instrumentations to capture them even though it is not recommended.

          The attribute value MUST consist of either multiple header values as an array of strings
          or a single-item array containing a possibly comma-concatenated string, depending on the way
          the HTTP library provides access to headers.
        examples: ['http.request.header.content-type=["application/json"]', 'http.request.header.x-forwarded-for=["1.2.3.4", "1.2.3.5"]']
      - id: request.method
        stability: stable
        type:
          allow_custom_values: true
          members:
            - id: connect
              value: "CONNECT"
              brief: 'CONNECT method.'
            - id: delete
              value: "DELETE"
              brief: 'DELETE method.'
            - id: get
              value: "GET"
              brief: 'GET method.'
            - id: head
              value: "HEAD"
              brief: 'HEAD method.'
            - id: options
              value: "OPTIONS"
              brief: 'OPTIONS method.'
            - id: patch
              value: "PATCH"
              brief: 'PATCH method.'
            - id: post
              value: "POST"
              brief: 'POST method.'
            - id: put
              value: "PUT"
              brief: 'PUT method.'
            - id: trace
              value: "TRACE"
              brief: 'TRACE method.'
            - id: other
              value: "_OTHER"
              brief: 'Any HTTP method that the instrumentation has no prior knowledge of.'
        brief: 'HTTP request method.'
        examples: ["GET", "POST", "HEAD"]
        note: |
          HTTP request method value SHOULD be "known" to the instrumentation.
          By default, this convention defines "known" methods as the ones listed in [RFC9110](https://www.rfc-editor.org/rfc/rfc9110.html#name-methods)
          and the PATCH method defined in [RFC5789](https://www.rfc-editor.org/rfc/rfc5789.html).

          If the HTTP request method is not known to instrumentation, it MUST set the `http.request.method` attribute to `_OTHER`.

          If the HTTP instrumentation could end up converting valid HTTP request methods to `_OTHER`, then it MUST provide a way to override
          the list of known HTTP methods. If this override is done via environment variable, then the environment variable MUST be named
          OTEL_INSTRUMENTATION_HTTP_KNOWN_METHODS and support a comma-separated list of case-sensitive known HTTP methods
          (this list MUST be a full override of the default known method, it is not a list of known methods in addition to the defaults).

          HTTP method names are case-sensitive and `http.request.method` attribute value MUST match a known HTTP method name exactly.
          Instrumentations for specific web frameworks that consider HTTP methods to be case insensitive, SHOULD populate a canonical equivalent.
          Tracing instrumentations that do so, MUST also set `http.request.method_original` to the original value.
      - id: request.method_original
        stability: stable
        type: string
        brief: Original HTTP method sent by the client in the request line.
        examples: ["GeT", "ACL", "foo"]
      - id: request.resend_count
        stability: stable
        type: int
        brief: >
          The ordinal number of request resending attempt (for any reason, including redirects).
        note: >
          The resend count SHOULD be updated each time an HTTP request gets resent by the client, regardless of what
          was the cause of the resending (e.g. redirection, authorization failure, 503 Server Unavailable, network issues,
          or any other).
        examples: 3
      - id: response.body.size
        type: int
        brief: >
          The size of the response payload body in bytes. This is the number of bytes transferred excluding headers and
          is often, but not always, present as the [Content-Length](https://www.rfc-editor.org/rfc/rfc9110.html#field.content-length)
          header. For requests using transport encoding, this should be the compressed size.
        examples: 3495
        stability: experimental  # this should not be marked stable with other HTTP attributes
      - id: response.header
        stability: stable
        type: template[string[]]
        brief: >
          HTTP response headers, `<key>` being the normalized HTTP Header name (lowercase), the value being the header values.
        note: >
          Instrumentations SHOULD require an explicit configuration of which headers are to be captured.
          Including all response headers can be a security risk - explicit configuration helps avoid leaking sensitive information.

          Users MAY explicitly configure instrumentations to capture them even though it is not recommended.

          The attribute value MUST consist of either multiple header values as an array of strings
          or a single-item array containing a possibly comma-concatenated string, depending on the way
          the HTTP library provides access to headers.
        examples: ['http.response.header.content-type=["application/json"]', 'http.response.header.my-custom-header=["abc", "def"]']
      - id: response.status_code
        stability: stable
        type: int
        brief: '[HTTP response status code](https://tools.ietf.org/html/rfc7231#section-6).'
        examples: [200]
      - id: route
        stability: stable
        type: string
        brief: >
            The matched route, that is, the path template in the format used by the respective server framework.
        examples: ['/users/:userID?', '{controller}/{action}/{id?}']
        note: >
          MUST NOT be populated when this is not supported by the HTTP server framework as the route attribute should have low-cardinality and the URI path can NOT substitute it.

          SHOULD include the [application root](/docs/http/http-spans.md#http-server-definitions) if there is one.
