Message rules

MessageConstraints represents validation rules that are applied to the entire message. It includes disabling options and a list of Constraint messages representing Common Expression Language (CEL) validation rules.

disabled

disabled is a boolean flag that, when set to true, nullifies any validation rules for this message. This includes any fields within the message that would otherwise support validation.

message.disabled example

message MyMessage {
  // validation will be bypassed for this message
  option (buf.validate.message).disabled = true;
}

cel

cel is a repeated field of type Constraint. Each Constraint specifies a validation rule to be applied to this message. These constraints are written in Common Expression Language (CEL) syntax. For more information on CEL, see our documentation.

message.cel example

message MyMessage {
  // The field `foo` must be greater than 42.
  option (buf.validate.message).cel = {
    id: "my_message.value",
    message: "value must be greater than 42",
    expression: "this.foo > 42",
  };
  optional int32 foo = 1;
}