// SPDX-License-Identifier: Apache-2.0

//

// WARNING: This file is automatically generated! Please edit onnx.in.proto.

//

syntax = "proto3";

package onnx;

// Overview

//

// ONNX is an open specification that is comprised of the following components:

//

// 1) A definition of an extensible computation graph model.

// 2) Definitions of standard data types.

// 3) Definitions of built-in operators.

//

// This document describes the syntax of models and their computation graphs,

// as well as the standard data types. Together, they are referred to as the ONNX

// Intermediate Representation, or 'IR' for short.

//

// The normative semantic specification of the ONNX IR is found in docs/IR.md.

// Definitions of the built-in neural network operators may be found in docs/Operators.md.

// Definitions of the built-in classical machine learning operators may be found in

// docs/Operators-ml.md.

// Notes

//

// Release

//

// We are still in the very early stage of defining ONNX. The current

// version of ONNX is a starting point. While we are actively working

// towards a complete spec, we would like to get the community involved

// by sharing our working version of ONNX.

//

// Protobuf compatibility

//

// To simplify framework compatibility, ONNX is defined using the subset of protobuf

// that is compatible with both protobuf v2 and v3. This means that we do not use any

// protobuf features that are only available in one of the two versions.

//

// Here are the most notable contortions we have to carry out to work around

// these limitations:

//

// - No 'map' (added protobuf 3.0). We instead represent mappings as lists

// of key-value pairs, where order does not matter and duplicates

// are not allowed.

// Versioning

//

// ONNX versioning is specified in docs/IR.md and elaborated on in docs/Versioning.md

//

// To be compatible with both proto2 and proto3, we will use a version number

// that is not defined by the default value but an explicit enum number.

enum Version {

// proto3 requires the first enum value to be zero.

// We add this just to appease the compiler.

_START_VERSION = 0;

// The version field is always serialized and we will use it to store the

// version that the graph is generated from. This helps us set up version

// control.

// For the IR, we are using simple numbers starting with with 0x00000001,

// which was the version we published on Oct 10, 2017.

IR_VERSION_2017_10_10 = 0x0000000000000001;

// IR_VERSION 2 published on Oct 30, 2017

// - Added type discriminator to AttributeProto to support proto3 users

IR_VERSION_2017_10_30 = 0x0000000000000002;

// IR VERSION 3 published on Nov 3, 2017

// - For operator versioning:

// - Added new message OperatorSetIdProto

// - Added opset_import in ModelProto

// - For vendor extensions, added domain in NodeProto

IR_VERSION_2017_11_3 = 0x0000000000000003;

// IR VERSION 4 published on Jan 22, 2019

// - Relax constraint that initializers should be a subset of graph inputs

// - Add type BFLOAT16

IR_VERSION_2019_1_22 = 0x0000000000000004;

// IR VERSION 5 published on March 18, 2019

// - Add message TensorAnnotation.

// - Add quantization annotation in GraphProto to map tensor with its scale and zero point quantization parameters.

IR_VERSION = 0x0000000000000005;

}

// Attributes

//

// A named attribute containing either singular float, integer, string, graph,

// and tensor values, or repeated float, integer, string, graph, and tensor values.

// An AttributeProto MUST contain the name field, and *only one* of the

// following content fields, effectively enforcing a C/C++ union equivalent.

message AttributeProto {

// Note: this enum is structurally identical to the OpSchema::AttrType

// enum defined in schema.h. If you rev one, you likely need to rev the other.

enum AttributeType {

UNDEFINED = 0;

FLOAT = 1;

INT = 2;

STRING = 3;

TENSOR = 4;

GRAPH = 5;

FLOATS = 6;

INTS = 7;

STRINGS = 8;

TENSORS = 9;

GRAPHS = 10;

}

// The name field MUST be present for this version of the IR.

string name = 1; // namespace Attribute

// if ref_attr_name is not empty, ref_attr_name is the attribute name in parent function.

// In this case, this AttributeProto does not contain data, and it's a reference of attribute

// in parent scope.

// NOTE: This should ONLY be used in function (sub-graph). It's invalid to be used in main graph.

string ref_attr_name = 21;

// A human-readable documentation for this attribute. Markdown is allowed.

string doc_string = 13;

// The type field MUST be present for this version of the IR.

// For 0.0.1 versions of the IR, this field was not defined, and

// implementations needed to use has_field hueristics to determine

// which value field was in use. For IR_VERSION 0.0.2 or later, this

// field MUST be set and match the f|i|s|t|... field in use. This

// change was made to accomodate proto3 implementations.

AttributeType type = 20; // discriminator that indicates which field below is in use

// Exactly ONE of the following fields must be present for this version of the IR

float f = 2; // float

int64 i = 3; // int

bytes s = 4; // UTF-8 string

TensorProto t = 5; // tensor value

GraphProto g = 6; // graph

// Do not use field below, it's deprecated.

// optional ValueProto v = 12; // value - subsumes everything but graph

repeated float floats = 7; // list of floats

repeated int64 ints = 8; // list of ints

repeated bytes strings = 9; // list of UTF-8 strings

repeated TensorProto tensors = 10; // list of tensors

repeated GraphProto graphs = 11; // list of graph

}

// Defines information on value, including the name, the type, and

// the shape of the value.

message ValueInfoProto {

// This field MUST be present in this version of the IR.

string name = 1; // namespace Value

// This field MUST be present in this version of the IR.

TypeProto type = 2;

// A human-readable documentation for this value. Markdown is allowed.

string doc_string = 3;

}

// Nodes

//

// Computation graphs are made up of a DAG of nodes, which represent what is

// commonly called a "layer" or "pipeline stage" in machine learning frameworks.

//

// For example, it can be a node of type "Conv" that takes in an image, a filter

// tensor and a bias tensor, and produces the convolved output.

message NodeProto {

repeated string input = 1; // namespace Value

repeated string output = 2; // namespace Value

// An optional identifier for this node in a graph.

// This field MAY be absent in ths version of the IR.

string name = 3; // namespace Node

// The symbolic identifier of the Operator to execute.

string op_type = 4; // namespace Operator

// The domain of the OperatorSet that specifies the operator named by op_type.

string domain = 7; // namespace Domain

// Additional named attributes.

repeated AttributeProto attribute = 5;

// A human-readable documentation for this node. Markdown is allowed.

string doc_string = 6;

}

// Models

//

// ModelProto is a top-level file/container format for bundling a ML model and

// associating its computation graph with metadata.

//

// The semantics of the model are described by the associated GraphProto.

message ModelProto {

// The version of the IR this model targets. See Version enum above.

// This field MUST be present.

int64 ir_version = 1;

// The OperatorSets this model relies on.

// All ModelProtos MUST have at least one entry that

// specifies which version of the ONNX OperatorSet is

// being imported.

//

// All nodes in the ModelProto's graph will bind against the operator

// with the same-domain/same-op_type operator with the HIGHEST version

// in the referenced operator sets.

repeated OperatorSetIdProto opset_import = 8;

// The name of the framework or tool used to generate this model.

// This field SHOULD be present to indicate which implementation/tool/framework

// emitted the model.

string producer_name = 2;

// The version of the framework or tool used to generate this model.

// This field SHOULD be present to indicate which implementation/tool/framework

// emitted the model.

string producer_version = 3;

// Domain name of the model.

// We use reverse domain names as name space indicators. For example:

// `com.facebook.fair` or `com.microsoft.cognitiveservices`

//

// Together with `model_version` and GraphProto.name, this forms the unique identity of

// the graph.

string domain = 4;

// The version of the graph encoded. See Version enum below.

int64 model_version = 5;

// A human-readable documentation for this model. Markdown is allowed.

string doc_string = 6;

// The parameterized graph that is evaluated to execute the model.

GraphProto graph = 7;

// kezhan: This field is not in ONNX, and will be pushed into ONNX with good use cases in microsoft.

repeated FunctionProto functions = 100;

// Named metadata values; keys should be distinct.

repeated StringStringEntryProto metadata_props = 14;

};

// StringStringEntryProto follows the pattern for cross-proto-version maps.

// See https://developers.google.com/protocol-buffers/docs/proto3#maps

message StringStringEntryProto {

string key = 1;

string value= 2;

};

message TensorAnnotation {

string tensor_name = 1;

// <key, value> pairs to annotate tensor specified by <tensor_name> above.

// The keys used in the mapping below must be pre-defined in ONNX spec.

// For example, for 8-bit linear quantization case, 'SCALE_TENSOR', 'ZERO_POINT_TENSOR' will be pre-defined as

// quantization parameter keys.

repeated StringStringEntryProto quant_parameter_tensor_names = 2;

}

// Graphs

//

// A graph defines the computational logic of a model and is comprised of a parameterized

// list of nodes that form a directed acyclic graph based on their inputs and outputs.

// This is the equivalent of the "network" or "graph" in many deep learning

// frameworks.

message GraphProto {

// The nodes in the graph, sorted topologically.

repeated NodeProto node = 1;

// The name of the graph.

string name = 2; // namespace Graph

// A list of named tensor values, used to specify constant inputs of the graph.

// Each TensorProto entry must have a distinct name (within the list) that

// MAY also appear in the input list.

repeated TensorProto initializer = 5;

// A human-readable documentation for this graph. Markdown is allowed.

string doc_string = 10;

// The inputs and outputs of the graph.

repeated ValueInfoProto input = 11;

repeated ValueInfoProto output = 12;

// Information for the values in the graph. The ValueInfoProto.name's

// must be distinct. It is optional for a value to appear in value_info list.

repeated ValueInfoProto value_info = 13;

// This field carries information to indicate the mapping among a tensor and its

// quantization parameter tensors. For example:

// For tensor 'a', it may have {'SCALE_TENSOR', 'a_scale'} and {'ZERO_POINT_TENSOR', 'a_zero_point'} annotated,

// which means, tensor 'a_scale' and tensor 'a_zero_point' are scale and zero point of tensor 'a' in the model.

repeated TensorAnnotation quantization_annotation = 14;

// DO NOT USE the following fields, they were deprecated from earlier versions.

// repeated string input = 3;

// repeated string output = 4;

// optional int64 ir_version = 6;

// optional int64 producer_version = 7;

// optional string producer_tag = 8;

// optional string domain = 9;

}

// Tensors

//

// A serialized tensor value.

message TensorProto {

enum DataType {

UNDEFINED = 0;

// Basic types.

FLOAT = 1; // float

UINT8 = 2; // uint8_t

INT8 = 3; // int8_t

UINT16 = 4; // uint16_t

INT16 = 5; // int16_t

INT32 = 6; // int32_t

INT64 = 7; // int64_t

STRING = 8; // string

BOOL = 9; // bool

// IEEE754 half-precision floating-point format (16 bits wide).

// This format has 1 sign bit, 5 exponent bits, and 10 mantissa bits.

FLOAT16 = 10;

DOUBLE = 11;

UINT32 = 12;

UINT64 = 13;

COMPLEX64 = 14; // complex with float32 real and imaginary components

COMPLEX128 = 15; // complex with float64 real and imaginary components

// Non-IEEE floating-point format based on IEEE754 single-precision

// floating-point number truncated to 16 bits.

// This format has 1 sign bit, 8 exponent bits, and 7 mantissa bits.

BFLOAT16 = 16;

// Future extensions go here.

}

// The shape of the tensor.

repeated int64 dims = 1;

// The data type of the tensor.

// This field MUST have a valid TensorProto.DataType value

int32 data_type = 2;

// For very large tensors, we may want to store them in chunks, in which

// case the following fields will specify the segment that is stored in

// the current TensorProto.

message Segment {

int64 begin = 1;

int64 end = 2;

}

Segment segment = 3;

// Tensor content must be organized in row-major order.

//

// Depending on the data_type field, exactly one of the fields below with

// name ending in _data is used to store the elements of the tensor.

// For float and complex64 values

// Complex64 tensors are encoded as a single array of floats,

// with the real components appearing in odd numbered positions,

// and the corresponding imaginary component apparing in the

// subsequent even numbered position. (e.g., [1.0 + 2.0i, 3.0 + 4.0i]

// is encoded as [1.0, 2.0 ,3.0 ,4.0]

// When this field is present, the data_type field MUST be FLOAT or COMPLEX64.

repeated float float_data = 4 [packed = true];

// For int32, uint8, int8, uint16, int16, bool, and float16 values

// float16 values must be bit-wise converted to an uint16_t prior

// to writing to the buffer.

// When this field is present, the data_type field MUST be

// INT32, INT16, INT8, UINT16, UINT8, BOOL, or FLOAT16

repeated int32 int32_data = 5 [packed = true];

// For strings.

// Each element of string_data is a UTF-8 encoded Unicode

// string. No trailing null, no leading BOM. The protobuf "string"

// scalar type is not used to match ML community conventions.

// When this field is present, the data_type field MUST be STRING

repeated bytes string_data = 6;

// For int64.

// When this field is present, the data_type field MUST be INT64

repeated int64 int64_data = 7 [packed = true];

// Optionally, a name for the tensor.

string name = 8; // namespace Value

// A human-readable documentation for this tensor. Markdown is allowed.

string doc_string = 12;

// Serializations can either use one of the fields above, or use this

// raw bytes field. The only exception is the string case, where one is

// required to store the content in the repeated bytes string_data field.

//

// When this raw_data field is used to store tensor value, elements MUST

// be stored in as fixed-width, little-endian order.

// Floating-point data types MUST be stored in IEEE 754 format.

// Complex64 elements must be written as two consecutive FLOAT values, real component first.

// Complex128 elements must be written as two consecutive DOUBLE values, real component first.

// Boolean type MUST be written one byte per tensor element (00000001 for true, 00000000 for false).

//

// Note: the advantage of specific field rather than the raw_data field is

// that in some cases (e.g. int data), protobuf does a better packing via

// variable length storage, and may lead to smaller binary footprint.

// When this field is present, the data_type field MUST NOT be STRING or UNDEFINED

bytes raw_data = 9;

// Data can be stored inside the protobuf file using type-specific fields or raw_data.

// Alternatively, raw bytes data can be stored in an external file, using the external_data field.

// external_data stores key-value pairs describing data location. Recognized keys are:

// - "location" (required) - POSIX filesystem path relative to the directory where the ONNX

// protobuf model was stored

// - "offset" (optional) - position of byte at which stored data begins. Integer stored as string.

// Offset values SHOULD be multiples 4096 (page size) to enable mmap support.

// - "length" (optional) - number of bytes containing data. Integer stored as string.

// - "checksum" (optional) - SHA1 digest of file specified in under 'location' key.

repeated StringStringEntryProto external_data = 13;

// Location of the data for this tensor. MUST be one of:

// - DEFAULT - data stored inside the protobuf message. Data is stored in raw_data (if set) otherwise in type-specified field.

// - EXTERNAL - data stored in an external location as described by external_data field.

enum DataLocation {

DEFAULT = 0;

EXTERNAL = 1;

}

// If value not set, data is stored in raw_data (if set) otherwise in type-specified field.

DataLocation data_location = 14;

// For double

// Complex128 tensors are encoded as a single array of doubles,

// with the real components appearing in odd numbered positions,

// and the corresponding imaginary component apparing in the

// subsequent even numbered position. (e.g., [1.0 + 2.0i, 3.0 + 4.0i]

// is encoded as [1.0, 2.0 ,3.0 ,4.0]

// When this field is present, the data_type field MUST be DOUBLE or COMPLEX128

repeated double double_data = 10 [packed = true];

// For uint64 and uint32 values

// When this field is present, the data_type field MUST be

// UINT32 or UINT64

repeated uint64 uint64_data = 11 [packed = true];

}

// Defines a tensor shape. A dimension can be either an integer value

// or a symbolic variable. A symbolic variable represents an unknown

// dimension.

message TensorShapeProto {

message Dimension {

oneof value {

int64 dim_value = 1;

string dim_param = 2; // namespace Shape

};

// Standard denotation can optionally be used to denote tensor

// dimensions with standard semantic descriptions to ensure

// that operations are applied to the correct axis of a tensor.

// Refer to https://github.com/onnx/onnx/blob/master/docs/DimensionDenotation.md#denotation-definition

// for pre-defined dimension denotations.

string denotation = 3;

};

repeated Dimension dim = 1;

}

// Types

//

// The standard ONNX data types.

message TypeProto {

message Tensor {

// This field MUST NOT have the value of UNDEFINED

// This field MUST have a valid TensorProto.DataType value

// This field MUST be present for this version of the IR.

int32 elem_type = 1;

TensorShapeProto shape = 2;

}

// repeated T

message Sequence {

// The type and optional shape of each element of the sequence.

// This field MUST be present for this version of the IR.

TypeProto elem_type = 1;

};

// map<K,V>

message Map {

// This field MUST have a valid TensorProto.DataType value

// This field MUST be present for this version of the IR.

// This field MUST refer to an integral type ([U]INT{8|16|32|64}) or STRING

int32 key_type = 1;

// This field MUST be present for this version of the IR.

TypeProto value_type = 2;

};

message Opaque {

// When missing, the domain is the same as the model's.

string domain = 1;

// The name is optional but significant when provided.

string name = 2;

// parameters that help defining the type

// DEPRECATED do not use.

// repeated TypeProto parameters = 3;

}

message SparseTensor {

// This field MUST NOT have the value of UNDEFINED

// This field MUST have a valid TensorProto.DataType value

// This field MUST be present for this version of the IR.

int32 elem_type = 1;

TensorShapeProto shape = 2;

}

oneof value {

// The type of a tensor.

Tensor tensor_type = 1;

// NOTE: DNN-only implementations of ONNX MAY elect to not support non-tensor values

// as input and output to graphs and nodes. These types are needed to naturally

// support classical ML operators. DNN operators SHOULD restrict their input

// and output types to tensors.

// The type of a sequence.

Sequence sequence_type = 4;

// The type of a map.

Map map_type = 5;

Opaque opaque_type = 7;

SparseTensor sparse_tensor_type = 8;

}

// An optional denotation can be used to denote the whole

// type with a standard semantic description as to what is

// stored inside. Refer to https://github.com/onnx/onnx/blob/master/docs/TypeDenotation.md#type-denotation-definition

// for pre-defined type denotations.

string denotation = 6;

}

// Operator Sets

//

// OperatorSets are uniquely identified by a (domain, opset_version) pair.

message OperatorSetIdProto {

// The domain of the operator set being identified.

// The empty string ("") or absence of this field implies the operator

// set that is defined as part of the ONNX specification.

// This field MUST be present in this version of the IR when referring to any other operator set.

string domain = 1;

// The version of the operator set being identified.

// This field MUST be present in this version of the IR.

int64 version = 2;

}

// Operator/function status.

enum OperatorStatus {

EXPERIMENTAL = 0;

STABLE = 1;

}

message FunctionProto {

// The name of the function, similar usage of op_type in OperatorProto.

string name = 1;

// The first version of a function set which contains this function.

// When there's any breaking change for this function, the function set

// contains the function needs to bump its version, and since_version of

// the updated function will be changed to the updated function set version.

int64 since_version = 2;

// This field indicates whether the syntax, semantics, or presence

// of this function is in an experimental or stable stage. Once an

// function is published as STABLE, its syntax and semantics MUST NOT

// change in subsequent versions of the operator set.

// When a function is published as EXPERIMENTAL, the syntax and semantics

// of the function MAY change across operator set versions.

// Functions "become" stable by deprecating the experimental version and

// introducing a new stable function with the same name.

OperatorStatus status = 3;

// The inputs and outputs of the function.

repeated string input = 4;

repeated string output = 5;

// The attributes of the function.

repeated string attribute= 6;

// The nodes in the function.

repeated NodeProto node = 7;

// A human-readable documentation for this function. Markdown is allowed.

string doc_string = 8;

}