components/cronet/android/proto/flags.proto

// Describes the proto schema for HTTP flags.
//
// IMPORTANT: a copy of the proto schema described here is used by the HTTP
// flags producer, which is the responsibility of the host system. Be very
// careful about backward compatibility implications of any changes made in this
// file.

syntax = "proto2";

package org.chromium.net.httpflags;

option java_package = "org.chromium.net.httpflags";
option java_multiple_files = true;

// Describes the value that an HTTP flag should have, based on various criteria
// depending on the context in which the flag is used.
message FlagValue {
  // A possible value for this flag, along with a set of constraints that have
  // to be met for that value to be used.
  message ConstrainedValue {
    // App selector: only apply this value to applications whose package ID
    // matches the value of this field, e.g. "com.google.foo".
    // If not set, matches all apps.
    optional string app_id = 1;

    // Only apply this value to client libraries running at least this version.
    //
    // Currently this refers to Cronet versions, which are in the form
    // <MAJOR>.<MINOR>.<BUILD>.<PATCH>.
    //
    // The comparison is done in the usual way version numbers are compared,
    // i.e. they are treated as numeric tuples and compared
    // lexicographically. If the tuple dimensions differ, the smallest tuple is
    // zero-extended to match. For example, a `min_version` of 4.5.6.0 (or
    // just 4.5.6) will match 4.5.6.0, 4.5.6.1, 4.5.7.0, 4.5.10.0, 4.6.0.0,
    // 5.0.0.0, etc. but will not match 4.5.5.99, 4.4.7.0, 3.6.7.1, etc.
    //
    // If not set, matches all versions. The empty string is not a valid value.
    optional string min_version = 2;

    // If set to true, Cronet will consider this flag value even if telemetry is
    // disabled. By default, flags are NOT applied if telemetry is disabled, to
    // avoid "blindly" pushing flags to apps that cannot tell us about
    // regressions in Cronet metrics.
    //
    // Note that in the case of the Cronet API layer, if the app does not
    // explicitly opt in or out of telemetry through its manifest, then it is
    // not possible to know in advance if telemetry is going to be enabled or
    // disabled, because that depends on the source which is not yet known. In
    // this case, we use a heuristic where we treat telemetry as disabled if the
    // app happens to bundle native Cronet.
    //
    // Note: this field was introduced in July 2025; older versions of Cronet
    // will not honor this flag, and will behave as if it is set to true.
    optional bool apply_even_if_cronet_telemetry_disabled = 8;

    // If none of these fields are set, the flag is deemed to be unset.
    oneof value {
      bool bool_value = 3;
      int64 int_value = 4;
      float float_value = 5;
      string string_value = 6;
      bytes bytes_value = 7;
    }
  }

  // Each entry in this list is tried in turn, and the first entry to match
  // determines the flag value. If no entries match, the flag is deemed to be
  // unset.
  repeated ConstrainedValue constrained_values = 8;
}

// The format of the HTTP flags file is defined as the binary representation of
// an instance of this proto.
message Flags {
  // The key is the name of the flag. For example, "Cronet_log_me".
  map<string, FlagValue> flags = 1;
}