feat: support older ONNX Runtime versions (#524)

.github/workflows/other-checks.yml

@@ -49,3 +49,19 @@ jobs:
         run: |
           cargo check -p ort
           cargo check -p ort --features load-dynamic
+  multiversion:
+    name: Multiversion
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - name: Install stable Rust toolchain
+        uses: dtolnay/rust-toolchain@1.88
+      - uses: Swatinem/rust-cache@v2.7.8
+      - name: Run checks
+        run: |
+          cargo check -p ort --no-default-features --features api-17
+          cargo check -p ort --no-default-features --features api-18
+          cargo check -p ort --no-default-features --features api-19
+          cargo check -p ort --no-default-features --features api-20
+          cargo check -p ort --no-default-features --features api-21
+          cargo check -p ort --no-default-features --features api-22

Cargo.toml

@@ -47,7 +47,7 @@ targets = ["x86_64-unknown-linux-gnu", "wasm32-unknown-unknown"]
 rustdoc-args = [ "--cfg", "docsrs" ]
 
 [features]
-default = [ "std", "ndarray", "tracing", "download-binaries", "tls-native", "copy-dylibs" ]
+default = [ "std", "ndarray", "tracing", "download-binaries", "tls-native", "copy-dylibs", "api-23" ]
 
 std = [ "ort-sys/std", "ndarray/std", "tracing?/std" ]
 training = [ "ort-sys/training" ]
@@ -64,6 +64,14 @@ load-dynamic = [ "std", "preload-dylibs", "ort-sys/disable-linking" ]
 copy-dylibs = [ "ort-sys/copy-dylibs" ]
 pkg-config = [ "ort-sys/pkg-config" ]
 
+api-17 = [ "ort-sys/api-17" ]
+api-18 = [ "ort-sys/api-18", "api-17" ]
+api-19 = [ "ort-sys/api-19", "api-18" ]
+api-20 = [ "ort-sys/api-20", "api-19" ]
+api-21 = [ "ort-sys/api-21", "api-20" ]
+api-22 = [ "ort-sys/api-22", "api-21" ]
+api-23 = [ "ort-sys/api-23", "api-22" ]
+
 tls-rustls = [ "ort-sys/tls-rustls", "ureq?/rustls" ]
 tls-rustls-no-provider = [ "ort-sys/tls-rustls-no-provider", "ureq?/rustls-no-provider" ]
 tls-native = [ "ort-sys/tls-native", "ureq?/native-tls" ]

backends/candle/Cargo.toml

@@ -31,7 +31,7 @@ path = "lib.rs"
 [features]
 
 [workspace.dependencies]
-ort-sys = { version = "=2.0.0-rc.11", path = "../../ort-sys", default-features = false }
+ort-sys = { version = "=2.0.0-rc.11", path = "../../ort-sys", default-features = false, features = [ "api-17" ] }
 
 [dependencies]
 ort-sys = { workspace = true }
@@ -40,7 +40,7 @@ candle-onnx = { version = "=0.9.2" }
 prost = { version = "0.14.1", default-features = false }
 
 [dev-dependencies]
-ort = { version = "=2.0.0-rc.11", path = "../../", default-features = false, features = [ "alternative-backend", "fetch-models", "tls-rustls" ] }
+ort = { version = "=2.0.0-rc.11", path = "../../", default-features = false, features = [ "alternative-backend", "fetch-models", "tls-rustls", "api-17" ] }
 
 [[test]]
 name = "memory"

backends/candle/standalone/lib.rs

@@ -9,7 +9,7 @@ unsafe extern "system" fn get_version_string() -> *const ort_sys::c_char {
 }
 
 unsafe extern "system" fn get_api(version: u32) -> *const ort_sys::OrtApi {
-	if version <= 23 { &API as *const _ } else { core::ptr::null() }
+	if version <= ort_sys::ORT_API_VERSION { &API as *const _ } else { core::ptr::null() }
 }
 
 #[unsafe(no_mangle)]

backends/tract/Cargo.toml

@@ -31,7 +31,7 @@ path = "lib.rs"
 [features]
 
 [workspace.dependencies]
-ort-sys = { version = "=2.0.0-rc.11", path = "../../ort-sys", default-features = false }
+ort-sys = { version = "=2.0.0-rc.11", path = "../../ort-sys", default-features = false, features = [ "api-17" ] }
 
 [dependencies]
 ort-sys = { workspace = true }
@@ -39,7 +39,7 @@ tract-onnx = "0.22"
 parking_lot = "0.12"
 
 [dev-dependencies]
-ort = { version = "=2.0.0-rc.11", path = "../../", default-features = false, features = [ "alternative-backend", "fetch-models", "tls-rustls", "ndarray" ] }
+ort = { version = "=2.0.0-rc.11", path = "../../", default-features = false, features = [ "alternative-backend", "fetch-models", "tls-rustls", "ndarray", "api-17" ] }
 image = "0.25"
 ndarray = "0.17"
 

backends/tract/standalone/lib.rs

@@ -9,7 +9,7 @@ unsafe extern "system" fn get_version_string() -> *const ort_sys::c_char {
 }
 
 unsafe extern "system" fn get_api(version: u32) -> *const ort_sys::OrtApi {
-	if version <= 23 { &API as *const _ } else { core::ptr::null() }
+	if version <= ort_sys::ORT_API_VERSION { &API as *const _ } else { core::ptr::null() }
 }
 
 #[no_mangle]

backends/web/Cargo.toml

@@ -23,8 +23,8 @@ path = "lib.rs"
 
 [dependencies]
 js-sys = "0.3"
-ort = { path = "../../", version = "=2.0.0-rc.11", default-features = false, features = [ "alternative-backend" ] }
-ort-sys = { path = "../../ort-sys", version = "=2.0.0-rc.11", default-features = false, features = [ "disable-linking" ] }
+ort = { path = "../../", version = "=2.0.0-rc.11", default-features = false, features = [ "alternative-backend", "api-17" ] }
+ort-sys = { path = "../../ort-sys", version = "=2.0.0-rc.11", default-features = false, features = [ "disable-linking", "api-17" ] }
 serde = { version = "1.0", features = [ "derive" ] }
 serde-wasm-bindgen = "0.6"
 wasm-bindgen = "0.2"

ort-sys/Cargo.toml

@@ -20,15 +20,22 @@ build = "build/main.rs"
 status = "actively-developed"
 
 [features]
-default = [ "std" ]
+default = [ "std", "api-17" ]
 std = []
 pkg-config = [ "dep:pkg-config" ]
 training = []
 download-binaries = [ "dep:ureq", "dep:lzma-rust2", "dep:hmac-sha256" ]
 copy-dylibs = []
-
 disable-linking = []
 
+api-17 = []
+api-18 = [ "api-17" ]
+api-19 = [ "api-18" ]
+api-20 = [ "api-19" ]
+api-21 = [ "api-20" ]
+api-22 = [ "api-21" ]
+api-23 = [ "api-22" ]
+
 cuda = []
 tensorrt = []
 openvino = []

ort-sys/src/lib.rs

@@ -1502,19 +1502,23 @@ pub struct OrtApi {
 		provider_options_values: *const *const core::ffi::c_char,
 		num_keys: usize
 	) -> OrtStatusPtr,
+	#[cfg(feature = "api-18")]
 	pub SessionOptionsAppendExecutionProvider_VitisAI: unsafe extern "system" fn(
 		options: *mut OrtSessionOptions,
 		provider_options_keys: *const *const core::ffi::c_char,
 		provider_options_values: *const *const core::ffi::c_char,
 		num_keys: usize
 	) -> OrtStatusPtr,
+	#[cfg(feature = "api-18")]
 	pub KernelContext_GetScratchBuffer: unsafe extern "system" fn(
 		context: *const OrtKernelContext,
 		mem_info: *const OrtMemoryInfo,
 		count_or_bytes: usize,
 		out: *mut *mut core::ffi::c_void
 	) -> OrtStatusPtr,
+	#[cfg(feature = "api-18")]
 	pub KernelInfoGetAllocator: unsafe extern "system" fn(info: *const OrtKernelInfo, mem_type: OrtMemType, out: *mut *mut OrtAllocator) -> OrtStatusPtr,
+	#[cfg(feature = "api-18")]
 	pub AddExternalInitializersFromMemory: unsafe extern "system" fn(
 		options: *mut OrtSessionOptions,
 		external_initializer_file_names: *const *const os_char,
@@ -1522,29 +1526,42 @@ pub struct OrtApi {
 		external_initializer_file_lengths: *const usize,
 		num_external_initializer_files: usize
 	) -> OrtStatusPtr,
+	#[cfg(feature = "api-20")]
 	pub CreateLoraAdapter:
 		unsafe extern "system" fn(adapter_file_path: *const os_char, allocator: *mut OrtAllocator, out: *mut *mut OrtLoraAdapter) -> OrtStatusPtr,
+	#[cfg(feature = "api-20")]
 	pub CreateLoraAdapterFromArray: unsafe extern "system" fn(
 		bytes: *const core::ffi::c_void,
 		num_bytes: usize,
 		allocator: *mut OrtAllocator,
 		out: *mut *mut OrtLoraAdapter
 	) -> OrtStatusPtr,
+	#[cfg(feature = "api-20")]
 	pub ReleaseLoraAdapter: unsafe extern "system" fn(input: *mut OrtLoraAdapter),
+	#[cfg(feature = "api-20")]
 	pub RunOptionsAddActiveLoraAdapter: unsafe extern "system" fn(options: *mut OrtRunOptions, adapter: *const OrtLoraAdapter) -> OrtStatusPtr,
+	#[cfg(feature = "api-20")]
 	pub SetEpDynamicOptions: unsafe extern "system" fn(
 		sess: *mut OrtSession,
 		keys: *const *const core::ffi::c_char,
 		values: *const *const core::ffi::c_char,
 		kv_len: usize
 	) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub ReleaseValueInfo: unsafe extern "system" fn(input: *mut OrtValueInfo),
+	#[cfg(feature = "api-22")]
 	pub ReleaseNode: unsafe extern "system" fn(input: *mut OrtNode),
+	#[cfg(feature = "api-22")]
 	pub ReleaseGraph: unsafe extern "system" fn(input: *mut OrtGraph),
+	#[cfg(feature = "api-22")]
 	pub ReleaseModel: unsafe extern "system" fn(input: *mut OrtModel),
+	#[cfg(feature = "api-22")]
 	pub GetValueInfoName: unsafe extern "system" fn(value_info: *const OrtValueInfo, name: *mut *const c_char) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub GetValueInfoTypeInfo: unsafe extern "system" fn(value_info: *const OrtValueInfo, type_info: *mut *const OrtTypeInfo) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub GetModelEditorApi: unsafe extern "system" fn() -> *const OrtModelEditorApi,
+	#[cfg(feature = "api-22")]
 	pub CreateTensorWithDataAndDeleterAsOrtValue: unsafe extern "system" fn(
 		deleter: *mut OrtAllocator,
 		p_data: *mut c_void,
@@ -1554,18 +1571,30 @@ pub struct OrtApi {
 		r#type: ONNXTensorElementDataType,
 		out: *mut *mut OrtValue
 	) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub SessionOptionsSetLoadCancellationFlag: unsafe extern "system" fn(options: *mut OrtSessionOptions, cancel: bool) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub GetCompileApi: unsafe extern "system" fn() -> *const OrtCompileApi,
+	#[cfg(feature = "api-22")]
 	pub CreateKeyValuePairs: unsafe extern "system" fn(out: *mut *mut OrtKeyValuePairs),
+	#[cfg(feature = "api-22")]
 	pub AddKeyValuePair: unsafe extern "system" fn(kvps: *mut OrtKeyValuePairs, key: *const c_char, value: *const c_char),
+	#[cfg(feature = "api-22")]
 	pub GetKeyValue: unsafe extern "system" fn(kvps: *const OrtKeyValuePairs, key: *const c_char) -> *const c_char,
+	#[cfg(feature = "api-22")]
 	pub GetKeyValuePairs:
 		unsafe extern "system" fn(kvps: *const OrtKeyValuePairs, keys: *mut *const *const c_char, values: *mut *const *const c_char, num_entries: *mut usize),
+	#[cfg(feature = "api-22")]
 	pub RemoveKeyValuePair: unsafe extern "system" fn(kvps: *mut OrtKeyValuePairs, key: *const c_char),
+	#[cfg(feature = "api-22")]
 	pub ReleaseKeyValuePairs: unsafe extern "system" fn(input: *mut OrtKeyValuePairs),
+	#[cfg(feature = "api-22")]
 	pub RegisterExecutionProviderLibrary: unsafe extern "system" fn(env: *mut OrtEnv, registration_name: *const c_char, path: *const os_char) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub UnregisterExecutionProviderLibrary: unsafe extern "system" fn(env: *mut OrtEnv, registration_name: *const c_char) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub GetEpDevices: unsafe extern "system" fn(env: *const OrtEnv, ep_devices: *mut *const *const OrtEpDevice, num_ep_devices: *mut usize) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub SessionOptionsAppendExecutionProvider_V2: unsafe extern "system" fn(
 		session_options: *mut OrtSessionOptions,
 		env: *mut OrtEnv,
@@ -1575,20 +1604,33 @@ pub struct OrtApi {
 		ep_option_vals: *const *const c_char,
 		num_ep_options: usize
 	) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub SessionOptionsSetEpSelectionPolicy:
 		unsafe extern "system" fn(session_options: *mut OrtSessionOptions, policy: OrtExecutionProviderDevicePolicy) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub SessionOptionsSetEpSelectionPolicyDelegate:
 		unsafe extern "system" fn(session_options: *mut OrtSessionOptions, delegate: EpSelectionDelegate, delegate_state: *mut c_void) -> OrtStatusPtr,
+	#[cfg(feature = "api-22")]
 	pub HardwareDevice_Type: unsafe extern "system" fn(device: *const OrtHardwareDevice) -> OrtHardwareDeviceType,
+	#[cfg(feature = "api-22")]
 	pub HardwareDevice_VendorId: unsafe extern "system" fn(device: *const OrtHardwareDevice) -> u32,
+	#[cfg(feature = "api-22")]
 	pub HardwareDevice_Vendor: unsafe extern "system" fn(device: *const OrtHardwareDevice) -> *const c_char,
+	#[cfg(feature = "api-22")]
 	pub HardwareDevice_DeviceId: unsafe extern "system" fn(device: *const OrtHardwareDevice) -> u32,
+	#[cfg(feature = "api-22")]
 	pub HardwareDevice_Metadata: unsafe extern "system" fn(device: *const OrtHardwareDevice) -> *const OrtKeyValuePairs,
+	#[cfg(feature = "api-22")]
 	pub EpDevice_EpName: unsafe extern "system" fn(ep_device: *const OrtEpDevice) -> *const c_char,
+	#[cfg(feature = "api-22")]
 	pub EpDevice_EpVendor: unsafe extern "system" fn(ep_device: *const OrtEpDevice) -> *const c_char,
+	#[cfg(feature = "api-22")]
 	pub EpDevice_EpMetadata: unsafe extern "system" fn(ep_device: *const OrtEpDevice) -> *const OrtKeyValuePairs,
+	#[cfg(feature = "api-22")]
 	pub EpDevice_EpOptions: unsafe extern "system" fn(ep_device: *const OrtEpDevice) -> *const OrtKeyValuePairs,
+	#[cfg(feature = "api-22")]
 	pub EpDevice_Device: unsafe extern "system" fn(ep_device: *const OrtEpDevice) -> *const OrtHardwareDevice,
+	#[cfg(feature = "api-22")]
 	pub GetEpApi: unsafe extern "system" fn() -> *const OrtEpApi
 }
 #[repr(i32)]

ort-sys/src/stub.rs

@@ -1655,6 +1655,7 @@ unsafe extern "system" fn SessionOptionsAppendExecutionProvider_OpenVINO_V2(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-18")]
 unsafe extern "system" fn SessionOptionsAppendExecutionProvider_VitisAI(
 	options: *mut OrtSessionOptions,
 	provider_options_keys: *const *const ::core::ffi::c_char,
@@ -1664,6 +1665,7 @@ unsafe extern "system" fn SessionOptionsAppendExecutionProvider_VitisAI(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-18")]
 unsafe extern "system" fn KernelContext_GetScratchBuffer(
 	context: *const OrtKernelContext,
 	mem_info: *const OrtMemoryInfo,
@@ -1673,10 +1675,12 @@ unsafe extern "system" fn KernelContext_GetScratchBuffer(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-18")]
 unsafe extern "system" fn KernelInfoGetAllocator(info: *const OrtKernelInfo, mem_type: OrtMemType, out: *mut *mut OrtAllocator) -> OrtStatusPtr {
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-18")]
 unsafe extern "system" fn AddExternalInitializersFromMemory(
 	options: *mut OrtSessionOptions,
 	external_initializer_file_names: *const *const os_char,
@@ -1687,10 +1691,12 @@ unsafe extern "system" fn AddExternalInitializersFromMemory(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-20")]
 unsafe extern "system" fn CreateLoraAdapter(adapter_file_path: *const os_char, allocator: *mut OrtAllocator, out: *mut *mut OrtLoraAdapter) -> OrtStatusPtr {
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-20")]
 unsafe extern "system" fn CreateLoraAdapterFromArray(
 	bytes: *const ::core::ffi::c_void,
 	num_bytes: usize,
@@ -1700,12 +1706,15 @@ unsafe extern "system" fn CreateLoraAdapterFromArray(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-20")]
 unsafe extern "system" fn ReleaseLoraAdapter(input: *mut OrtLoraAdapter) {}
 
+#[cfg(feature = "api-20")]
 unsafe extern "system" fn RunOptionsAddActiveLoraAdapter(options: *mut OrtRunOptions, adapter: *const OrtLoraAdapter) -> OrtStatusPtr {
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-20")]
 unsafe extern "system" fn SetEpDynamicOptions(
 	sess: *mut OrtSession,
 	keys: *const *const ::core::ffi::c_char,
@@ -1715,26 +1724,34 @@ unsafe extern "system" fn SetEpDynamicOptions(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn ReleaseValueInfo(input: *mut OrtValueInfo) {}
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn ReleaseNode(input: *mut OrtNode) {}
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn ReleaseGraph(input: *mut OrtGraph) {}
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn ReleaseModel(input: *mut OrtModel) {}
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn GetValueInfoName(value_info: *const OrtValueInfo, name: *mut *const ::core::ffi::c_char) -> OrtStatusPtr {
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn GetValueInfoTypeInfo(value_info: *const OrtValueInfo, type_info: *mut *const OrtTypeInfo) -> OrtStatusPtr {
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn GetModelEditorApi() -> *const OrtModelEditorApi {
 	ptr::null()
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn CreateTensorWithDataAndDeleterAsOrtValue(
 	deleter: *mut OrtAllocator,
 	p_data: *mut ::core::ffi::c_void,
@@ -1747,24 +1764,30 @@ unsafe extern "system" fn CreateTensorWithDataAndDeleterAsOrtValue(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn SessionOptionsSetLoadCancellationFlag(options: *mut OrtSessionOptions, cancel: bool) -> OrtStatusPtr {
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn GetCompileApi() -> *const OrtCompileApi {
 	ptr::null_mut()
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn CreateKeyValuePairs(out: *mut *mut OrtKeyValuePairs) {
 	unsafe { *out = ptr::null_mut() };
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn AddKeyValuePair(kvps: *mut OrtKeyValuePairs, key: *const ::core::ffi::c_char, value: *const ::core::ffi::c_char) {}
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn GetKeyValue(kvps: *const OrtKeyValuePairs, key: *const ::core::ffi::c_char) -> *const ::core::ffi::c_char {
 	ptr::null()
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn GetKeyValuePairs(
 	kvps: *const OrtKeyValuePairs,
 	keys: *mut *const *const ::core::ffi::c_char,
@@ -1773,10 +1796,13 @@ unsafe extern "system" fn GetKeyValuePairs(
 ) {
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn RemoveKeyValuePair(kvps: *mut OrtKeyValuePairs, key: *const ::core::ffi::c_char) {}
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn ReleaseKeyValuePairs(input: *mut OrtKeyValuePairs) {}
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn RegisterExecutionProviderLibrary(
 	env: *mut OrtEnv,
 	registration_name: *const ::core::ffi::c_char,
@@ -1785,14 +1811,17 @@ unsafe extern "system" fn RegisterExecutionProviderLibrary(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn UnregisterExecutionProviderLibrary(env: *mut OrtEnv, registration_name: *const ::core::ffi::c_char) -> OrtStatusPtr {
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn GetEpDevices(env: *const OrtEnv, ep_devices: *mut *const *const OrtEpDevice, num_ep_devices: *mut usize) -> OrtStatusPtr {
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn SessionOptionsAppendExecutionProvider_V2(
 	session_options: *mut OrtSessionOptions,
 	env: *mut OrtEnv,
@@ -1805,6 +1834,7 @@ unsafe extern "system" fn SessionOptionsAppendExecutionProvider_V2(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn SessionOptionsSetEpSelectionPolicy(
 	session_options: *mut OrtSessionOptions,
 	policy: OrtExecutionProviderDevicePolicy
@@ -1812,6 +1842,7 @@ unsafe extern "system" fn SessionOptionsSetEpSelectionPolicy(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn SessionOptionsSetEpSelectionPolicyDelegate(
 	session_options: *mut OrtSessionOptions,
 	delegate: EpSelectionDelegate,
@@ -1820,46 +1851,57 @@ unsafe extern "system" fn SessionOptionsSetEpSelectionPolicyDelegate(
 	Error::new_sys(OrtErrorCode::ORT_NOT_IMPLEMENTED, "Unimplemented")
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn HardwareDevice_Type(device: *const OrtHardwareDevice) -> OrtHardwareDeviceType {
 	OrtHardwareDeviceType::OrtHardwareDeviceType_CPU
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn HardwareDevice_VendorId(device: *const OrtHardwareDevice) -> u32 {
 	0
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn HardwareDevice_Vendor(device: *const OrtHardwareDevice) -> *const ::core::ffi::c_char {
 	ptr::null()
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn HardwareDevice_DeviceId(device: *const OrtHardwareDevice) -> u32 {
 	0
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn HardwareDevice_Metadata(device: *const OrtHardwareDevice) -> *const OrtKeyValuePairs {
 	ptr::null()
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn EpDevice_EpName(ep_device: *const OrtEpDevice) -> *const ::core::ffi::c_char {
 	ptr::null()
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn EpDevice_EpVendor(ep_device: *const OrtEpDevice) -> *const ::core::ffi::c_char {
 	ptr::null()
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn EpDevice_EpMetadata(ep_device: *const OrtEpDevice) -> *const OrtKeyValuePairs {
 	ptr::null()
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn EpDevice_EpOptions(ep_device: *const OrtEpDevice) -> *const OrtKeyValuePairs {
 	ptr::null()
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn EpDevice_Device(ep_device: *const OrtEpDevice) -> *const OrtHardwareDevice {
 	ptr::null()
 }
 
+#[cfg(feature = "api-22")]
 unsafe extern "system" fn GetEpApi() -> *const OrtEpApi {
 	ptr::null()
 }
@@ -2142,47 +2184,89 @@ pub const fn api() -> OrtApi {
 		SetDeterministicCompute,
 		KernelContext_ParallelFor,
 		SessionOptionsAppendExecutionProvider_OpenVINO_V2,
+		#[cfg(feature = "api-18")]
 		SessionOptionsAppendExecutionProvider_VitisAI,
+		#[cfg(feature = "api-18")]
 		KernelContext_GetScratchBuffer,
+		#[cfg(feature = "api-18")]
 		KernelInfoGetAllocator,
+		#[cfg(feature = "api-18")]
 		AddExternalInitializersFromMemory,
+		#[cfg(feature = "api-20")]
 		CreateLoraAdapter,
+		#[cfg(feature = "api-20")]
 		CreateLoraAdapterFromArray,
+		#[cfg(feature = "api-20")]
 		ReleaseLoraAdapter,
+		#[cfg(feature = "api-20")]
 		RunOptionsAddActiveLoraAdapter,
+		#[cfg(feature = "api-20")]
 		SetEpDynamicOptions,
+		#[cfg(feature = "api-22")]
 		ReleaseValueInfo,
+		#[cfg(feature = "api-22")]
 		ReleaseNode,
+		#[cfg(feature = "api-22")]
 		ReleaseGraph,
+		#[cfg(feature = "api-22")]
 		ReleaseModel,
+		#[cfg(feature = "api-22")]
 		GetValueInfoName,
+		#[cfg(feature = "api-22")]
 		GetValueInfoTypeInfo,
+		#[cfg(feature = "api-22")]
 		GetModelEditorApi,
+		#[cfg(feature = "api-22")]
 		CreateTensorWithDataAndDeleterAsOrtValue,
+		#[cfg(feature = "api-22")]
 		SessionOptionsSetLoadCancellationFlag,
+		#[cfg(feature = "api-22")]
 		GetCompileApi,
+		#[cfg(feature = "api-22")]
 		CreateKeyValuePairs,
+		#[cfg(feature = "api-22")]
 		AddKeyValuePair,
+		#[cfg(feature = "api-22")]
 		GetKeyValue,
+		#[cfg(feature = "api-22")]
 		GetKeyValuePairs,
+		#[cfg(feature = "api-22")]
 		RemoveKeyValuePair,
+		#[cfg(feature = "api-22")]
 		ReleaseKeyValuePairs,
+		#[cfg(feature = "api-22")]
 		RegisterExecutionProviderLibrary,
+		#[cfg(feature = "api-22")]
 		UnregisterExecutionProviderLibrary,
+		#[cfg(feature = "api-22")]
 		GetEpDevices,
+		#[cfg(feature = "api-22")]
 		SessionOptionsAppendExecutionProvider_V2,
+		#[cfg(feature = "api-22")]
 		SessionOptionsSetEpSelectionPolicy,
+		#[cfg(feature = "api-22")]
 		SessionOptionsSetEpSelectionPolicyDelegate,
+		#[cfg(feature = "api-22")]
 		HardwareDevice_Type,
+		#[cfg(feature = "api-22")]
 		HardwareDevice_VendorId,
+		#[cfg(feature = "api-22")]
 		HardwareDevice_Vendor,
+		#[cfg(feature = "api-22")]
 		HardwareDevice_DeviceId,
+		#[cfg(feature = "api-22")]
 		HardwareDevice_Metadata,
+		#[cfg(feature = "api-22")]
 		EpDevice_EpName,
+		#[cfg(feature = "api-22")]
 		EpDevice_EpVendor,
+		#[cfg(feature = "api-22")]
 		EpDevice_EpMetadata,
+		#[cfg(feature = "api-22")]
 		EpDevice_EpOptions,
+		#[cfg(feature = "api-22")]
 		EpDevice_Device,
+		#[cfg(feature = "api-22")]
 		GetEpApi
 	}
 }

ort-sys/src/version.rs

@@ -1 +1,10 @@
-pub const ORT_API_VERSION: u32 = 23;
+const V18: u32 = cfg!(feature = "api-18") as u32;
+const V19: u32 = cfg!(feature = "api-19") as u32;
+const V20: u32 = cfg!(feature = "api-20") as u32;
+const V21: u32 = cfg!(feature = "api-21") as u32;
+const V22: u32 = cfg!(feature = "api-22") as u32;
+const V23: u32 = cfg!(feature = "api-23") as u32;
+
+#[rustfmt::skip]
+pub const ORT_API_VERSION: u32 = 17 // minimum version
+	+ V18 + V19 + V20 + V21 + V22 + V23; // We can do this because each API also enables the one before it.

src/lib.rs

@@ -25,7 +25,11 @@ pub mod __private {
 #[macro_use]
 pub(crate) mod private;
 
+#[cfg(feature = "api-22")]
+#[cfg_attr(docsrs, doc(cfg(feature = "api-22")))]
 pub mod compiler;
+#[cfg(feature = "api-22")]
+#[cfg_attr(docsrs, doc(cfg(feature = "api-22")))]
 pub mod editor;
 pub mod environment;
 pub mod ep;
@@ -41,9 +45,11 @@ pub mod util;
 pub mod value;
 #[doc(hidden)]
 pub mod api {
+	pub use super::api as ort;
 	#[cfg(feature = "training")]
 	pub use super::training::training_api as training;
-	pub use super::{api as ort, compiler::compile_api as compile, editor::editor_api as editor};
+	#[cfg(feature = "api-22")]
+	pub use super::{compiler::compile_api as compile, editor::editor_api as editor};
 }
 
 #[deprecated = "import execution providers from `ort::ep` instead"]

src/operator/kernel.rs

@@ -104,6 +104,8 @@ impl KernelAttributes {
 		Ok(CString::from_vec_with_nul(name)?.into_string()?)
 	}
 
+	#[cfg(feature = "api-18")]
+	#[cfg_attr(docsrs, doc(cfg(feature = "api-18")))]
 	pub fn allocator(&self, mem_type: MemoryType) -> Result<Allocator> {
 		let mut ptr: *mut ort_sys::OrtAllocator = ptr::null_mut();
 		ortsys![unsafe KernelInfoGetAllocator(self.ptr.as_ptr(), mem_type.into(), &mut ptr)?; nonNull(ptr)];

src/session/adapter.rs

@@ -88,6 +88,7 @@ impl Drop for AdapterInner {
 /// session run.
 ///
 /// [`RunOptions::add_adapter`]: crate::session::RunOptions::add_adapter
+#[cfg_attr(docsrs, doc(cfg(feature = "api-20")))]
 #[derive(Debug, Clone)]
 pub struct Adapter {
 	pub(crate) inner: Arc<AdapterInner>

src/session/builder/impl_commit.rs

@@ -15,7 +15,9 @@ use std::path::PathBuf;
 
 use smallvec::SmallVec;
 
-use super::{EditableSession, SessionBuilder};
+#[cfg(feature = "api-22")]
+use super::EditableSession;
+use super::SessionBuilder;
 #[cfg(any(target_arch = "wasm32", feature = "std"))]
 use crate::error::{Error, ErrorCode};
 #[cfg(all(feature = "std", not(target_arch = "wasm32")))]
@@ -284,8 +286,8 @@ impl SessionBuilder {
 		})
 	}
 
-	#[cfg(feature = "std")]
-	#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+	#[cfg(all(feature = "std", feature = "api-22"))]
+	#[cfg_attr(docsrs, doc(cfg(all(feature = "std", feature = "api-22"))))]
 	pub fn edit_from_file<P>(self, model_filepath: P) -> Result<EditableSession>
 	where
 		P: AsRef<Path>
@@ -306,6 +308,8 @@ impl SessionBuilder {
 		EditableSession::new(session_ptr, self)
 	}
 
+	#[cfg(feature = "api-22")]
+	#[cfg_attr(docsrs, doc(cfg(feature = "api-22")))]
 	pub fn edit_from_memory(self, model_bytes: &[u8]) -> Result<EditableSession> {
 		let mut session_ptr: *mut ort_sys::OrtSession = ptr::null_mut();
 

src/session/builder/impl_options.rs

@@ -185,8 +185,8 @@ impl SessionBuilder {
 		Ok(self)
 	}
 
-	#[cfg(feature = "std")]
-	#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+	#[cfg(all(feature = "std", feature = "api-20"))]
+	#[cfg_attr(docsrs, doc(cfg(all(feature = "std", feature = "api-20"))))]
 	pub fn with_external_initializer_file_in_memory(mut self, file_name: impl AsRef<Path>, buffer: alloc::borrow::Cow<'static, [u8]>) -> Result<Self> {
 		let file_name = path_to_os_char(file_name);
 		let sizes = [buffer.len()];

src/session/builder/mod.rs

@@ -18,15 +18,17 @@ use crate::{
 	value::DynValue
 };
 
+#[cfg(feature = "api-22")]
+#[cfg_attr(docsrs, doc(cfg(feature = "api-22")))]
 mod editable;
 mod impl_commit;
 mod impl_config_keys;
 mod impl_options;
 
-pub use self::{
-	editable::EditableSession,
-	impl_options::{GraphOptimizationLevel, PrepackedWeights}
-};
+#[cfg(feature = "api-22")]
+#[cfg_attr(docsrs, doc(cfg(feature = "api-22")))]
+pub use self::editable::EditableSession;
+pub use self::impl_options::{GraphOptimizationLevel, PrepackedWeights};
 
 /// Creates a session using the builder pattern.
 ///

src/session/mod.rs

@@ -41,6 +41,7 @@ use crate::{
 	value::{DynValue, Outlet, Value, ValueType}
 };
 
+#[cfg(feature = "api-20")]
 mod adapter;
 #[cfg(all(feature = "std", not(target_arch = "wasm32")))]
 mod r#async;
@@ -50,19 +51,21 @@ mod io_binding;
 mod metadata;
 mod output;
 mod run_options;
+#[cfg(feature = "api-20")]
+#[cfg_attr(docsrs, doc(cfg(feature = "api-20")))]
+pub use self::adapter::Adapter;
 #[cfg(all(feature = "std", not(target_arch = "wasm32")))]
 pub use self::r#async::InferenceFut;
 #[cfg(all(feature = "std", not(target_arch = "wasm32")))]
 use self::r#async::{AsyncInferenceContext, InferenceFutInner};
+use self::{builder::SessionBuilder, run_options::UntypedRunOptions};
 pub use self::{
-	adapter::Adapter,
 	input::{SessionInputValue, SessionInputs},
 	io_binding::IoBinding,
 	metadata::ModelMetadata,
 	output::SessionOutputs,
 	run_options::{HasSelectedOutputs, NoSelectedOutputs, OutputSelector, RunOptions, SelectedOutputMarker}
 };
-use self::{builder::SessionBuilder, run_options::UntypedRunOptions};
 
 /// Holds onto an [`ort_sys::OrtSession`] pointer and its associated allocator.
 ///
@@ -628,6 +631,8 @@ impl Session {
 	/// # 	Ok(())
 	/// # }
 	/// ```
+	#[cfg(feature = "api-20")]
+	#[cfg_attr(docsrs, doc(cfg(feature = "api-20")))]
 	pub fn set_workload_type(&mut self, workload_type: WorkloadType) -> Result<()> {
 		static KEY: &[u8] = b"ep.dynamic.workload_type\0";
 		match workload_type {
@@ -636,11 +641,14 @@ impl Session {
 		}
 	}
 
+	#[cfg(feature = "api-20")]
 	pub(crate) fn set_dynamic_option(&mut self, key: *const c_char, value: *const c_char) -> Result<()> {
 		ortsys![unsafe SetEpDynamicOptions(self.inner.session_ptr.as_ptr(), &key, &value, 1)?];
 		Ok(())
 	}
 
+	#[cfg(feature = "api-22")]
+	#[cfg_attr(docsrs, doc(cfg(feature = "api-22")))]
 	pub fn opset_for_domain(&self, domain: impl AsRef<str>) -> Result<u32> {
 		with_cstr(domain.as_ref().as_bytes(), &|domain| {
 			let mut opset = 0;

src/session/run_options.rs

@@ -8,15 +8,14 @@ use core::{
 
 use smallvec::SmallVec;
 
+#[cfg(feature = "api-20")]
+use crate::session::adapter::{Adapter, AdapterInner};
 use crate::{
 	AsPointer,
 	error::Result,
 	logging::LogLevel,
 	ortsys,
-	session::{
-		Outlet,
-		adapter::{Adapter, AdapterInner}
-	},
+	session::Outlet,
 	util::{MiniMap, STACK_SESSION_OUTPUTS, with_cstr},
 	value::{DynValue, Value, ValueTypeMarker}
 };
@@ -150,6 +149,7 @@ impl SelectedOutputMarker for HasSelectedOutputs {}
 pub(crate) struct UntypedRunOptions {
 	pub(crate) ptr: NonNull<ort_sys::OrtRunOptions>,
 	pub(crate) outputs: OutputSelector,
+	#[cfg(feature = "api-20")]
 	adapters: Vec<Arc<AdapterInner>>
 }
 
@@ -215,6 +215,7 @@ impl RunOptions {
 			inner: Arc::new(UntypedRunOptions {
 				ptr,
 				outputs: OutputSelector::default(),
+				#[cfg(feature = "api-20")]
 				adapters: Vec::new()
 			}),
 			_marker: PhantomData
@@ -357,6 +358,8 @@ impl<O: SelectedOutputMarker> RunOptions<O> {
 		})
 	}
 
+	#[cfg(feature = "api-20")]
+	#[cfg_attr(docsrs, doc(cfg(feature = "api-20")))]
 	pub fn add_adapter(&mut self, adapter: &Adapter) -> Result<()> {
 		let Some(inner) = Arc::get_mut(&mut self.inner) else {
 			panic!("Expected RunOptions to have exclusive access");

src/value/type.rs

@@ -173,6 +173,7 @@ impl ValueType {
 
 	/// Converts this type to an [`ort_sys::OrtTypeInfo`] using the Model Editor API, so it shouldn't be used outside of
 	/// `crate::editor`
+	#[cfg(feature = "api-22")]
 	pub(crate) fn to_type_info(&self) -> Result<*mut ort_sys::OrtTypeInfo> {
 		let mut info_ptr: *mut ort_sys::OrtTypeInfo = ptr::null_mut();
 		match self {
@@ -311,6 +312,7 @@ impl Outlet {
 		&self.dtype
 	}
 
+	#[cfg(feature = "api-22")]
 	pub(crate) fn into_editor_value_info(self) -> Result<NonNull<ort_sys::OrtValueInfo>> {
 		let type_info = self.dtype.to_type_info()?;
 		let _guard = run_on_drop(|| ortsys![unsafe ReleaseTypeInfo(type_info)]);