diff --git a/pycyphal/application/file.py b/pycyphal/application/file.py
index ac5b1e9f..4ca5790a 100644
--- a/pycyphal/application/file.py
+++ b/pycyphal/application/file.py
@@ -43,9 +43,7 @@ class FileServer:
     The lifetime of this instance matches the lifetime of its node.
     """
 
-    def __init__(
-        self, node: pycyphal.application.Node, roots: typing.Iterable[typing.Union[str, pathlib.Path]]
-    ) -> None:
+    def __init__(self, node: pycyphal.application.Node, roots: typing.Iterable[str | pathlib.Path]) -> None:
         """
         :param node:
             The node instance to initialize the file server on.
@@ -85,7 +83,7 @@ def close() -> None:
         node.add_lifetime_hooks(start, close)
 
     @property
-    def roots(self) -> typing.List[pathlib.Path]:
+    def roots(self) -> list[pathlib.Path]:
         """
         File operations will be performed within these root directories.
         The first directory to match takes precedence.
@@ -94,7 +92,7 @@ def roots(self) -> typing.List[pathlib.Path]:
         """
         return self._roots
 
-    def locate(self, p: typing.Union[pathlib.Path, str, Path]) -> typing.Tuple[pathlib.Path, pathlib.Path]:
+    def locate(self, p: pathlib.Path | str | Path) -> tuple[pathlib.Path, pathlib.Path]:
         """
         Iterate through :attr:`roots` until a root r is found such that ``r/p`` exists and return ``(r, p)``.
         Otherwise, return nonexistent ``(roots[0], p)``.
@@ -413,7 +411,7 @@ async def move(self, src: str, dst: str, overwrite: bool = False) -> int:
         assert isinstance(res, Modify.Response)
         return int(res.error.value)
 
-    async def read(self, path: str, offset: int = 0, size: typing.Optional[int] = None) -> typing.Union[int, bytes]:
+    async def read(self, path: str, offset: int = 0, size: int | None = None) -> int | bytes:
         """
         Proxy for ``uavcan.file.Read``.
 
@@ -434,7 +432,7 @@ async def read(self, path: str, offset: int = 0, size: typing.Optional[int] = No
             data on success (empty if the offset is out of bounds or the file is empty).
         """
 
-        async def once() -> typing.Union[int, bytes]:
+        async def once() -> int | bytes:
             res = await self._call(Read, Read.Request(offset=offset, path=Path(path)))
             assert isinstance(res, Read.Response)
             if res.error.value != 0:
@@ -455,9 +453,7 @@ async def once() -> typing.Union[int, bytes]:
             offset += len(out)
         return data
 
-    async def write(
-        self, path: str, data: typing.Union[memoryview, bytes], offset: int = 0, *, truncate: bool = True
-    ) -> int:
+    async def write(self, path: str, data: memoryview | bytes, offset: int = 0, *, truncate: bool = True) -> int:
         """
         Proxy for ``uavcan.file.Write``.
 
@@ -479,7 +475,7 @@ async def write(
         :returns: See ``uavcan.file.Error``
         """
 
-        async def once(d: typing.Union[memoryview, bytes]) -> int:
+        async def once(d: memoryview | bytes) -> int:
             res = await self._call(
                 Write,
                 Write.Request(offset, path=Path(path), data=Unstructured(np.frombuffer(d, np.uint8))),
@@ -658,7 +654,13 @@ async def move(self, src: str, dst: str, overwrite: bool = False) -> None:
         assert isinstance(res, Modify.Response)
         _raise_on_error(res.error, f"{src}->{dst}")
 
-    async def read(self, path: str, offset: int = 0, size: typing.Optional[int] = None) -> bytes:
+    async def read(
+        self,
+        path: str,
+        offset: int = 0,
+        size: int | None = None,
+        progress: typing.Callable[[int, int | None], None] | None = None,
+    ) -> bytes:
         """
         Proxy for ``uavcan.file.Read``.
 
@@ -674,6 +676,10 @@ async def read(self, path: str, offset: int = 0, size: typing.Optional[int] = No
             If None (default), the entire file will be read (this may exhaust local memory).
             If zero, this call is a no-op.
 
+        :param progress:
+            Optional callback function that receives (bytes_read, total_size)
+            total_size will be None if size parameter is None
+
         :raises OSError: If the read operation failed; see ``uavcan.file.Error``
 
         :returns:
@@ -686,20 +692,26 @@ async def once() -> bytes:
             _raise_on_error(res.error, path)
             return bytes(res.data.value.tobytes())
 
-        if size is None:
-            size = 2**64
         data = b""
-        while len(data) < size:
+        while len(data) < (size or 2**64):
             out = await once()
             assert isinstance(out, bytes)
             if not out:
                 break
             data += out
             offset += len(out)
+            if progress:
+                progress(len(data), size)
         return data
 
     async def write(
-        self, path: str, data: typing.Union[memoryview, bytes], offset: int = 0, *, truncate: bool = True
+        self,
+        path: str,
+        data: memoryview | bytes,
+        offset: int = 0,
+        *,
+        truncate: bool = True,
+        progress: typing.Callable[[int, int], None] | None = None,
     ) -> None:
         """
         Proxy for ``uavcan.file.Write``.
@@ -719,10 +731,13 @@ async def write(
             If True, the rest of the file after ``offset + len(data)`` will be truncated.
             This is done by sending an empty write request, as prescribed by the Specification.
 
+        :param progress:
+            Optional callback function that receives (bytes_written, total_size)
+
         :raises OSError: If the write operation failed; see ``uavcan.file.Error``
         """
 
-        async def once(d: typing.Union[memoryview, bytes]) -> None:
+        async def once(d: memoryview | bytes) -> None:
             res = await self._call(
                 Write,
                 Write.Request(offset, path=Path(path), data=Unstructured(np.frombuffer(d, np.uint8))),
@@ -730,11 +745,16 @@ async def once(d: typing.Union[memoryview, bytes]) -> None:
             assert isinstance(res, Write.Response)
             _raise_on_error(res.error, path)
 
+        total_size = len(data)
+        bytes_written = 0
         limit = self.data_transfer_capacity
         while len(data) > 0:
             frag, data = data[:limit], data[limit:]
             await once(frag)
             offset += len(frag)
+            bytes_written += len(frag)
+            if progress:
+                progress(bytes_written, total_size)
         if truncate:
             await once(b"")
 
diff --git a/tests/application/file.py b/tests/application/file.py
index 0cd5aad6..bb23588c 100644
--- a/tests/application/file.py
+++ b/tests/application/file.py
@@ -2,6 +2,7 @@
 # This software is distributed under the terms of the MIT License.
 # Author: Pavel Kirienko <pavel@opencyphal.org>
 
+import math
 import sys
 import shutil
 import typing
@@ -13,8 +14,13 @@
 import pycyphal
 
 
+class ProgressTracker:
+    def __init__(self) -> None:
+        self.counter = 0
+
+
 @pytest.mark.asyncio
-async def _unittest_file(compiled: typing.List[pycyphal.dsdl.GeneratedPackageInfo]) -> None:
+async def _unittest_file(compiled: list[pycyphal.dsdl.GeneratedPackageInfo]) -> None:
     from pycyphal.application import make_node, NodeInfo
     from pycyphal.transport.udp import UDPTransport
     from pycyphal.application.file import FileClient, FileServer, Error
@@ -254,8 +260,28 @@ async def ls(path: str) -> typing.List[str]:
         assert e.value.errno == errno.ENOENT
 
         # Write into empty file
-        await cln.write("a/foo/x", bytes(range(200)) * 3)
-        assert await cln.read("a/foo/x") == bytes(range(200)) * 3
+        data = bytes(range(200)) * 3
+        data_chunks = math.ceil(len(data) / cln.data_transfer_capacity)
+        write_tracker = ProgressTracker()
+
+        def write_progress_cb(bytes_written: int, bytes_total: int) -> None:
+            write_tracker.counter += 1
+            assert bytes_total == len(data)
+            assert bytes_written == min(write_tracker.counter * cln.data_transfer_capacity, len(data))
+
+        await cln.write("a/foo/x", data, progress=write_progress_cb)
+        assert write_tracker.counter == data_chunks
+
+        read_tracker = ProgressTracker()
+
+        def read_progress_cb(bytes_read: int, bytes_total: int | None) -> None:
+            read_tracker.counter += 1
+            assert bytes_total is None
+            assert bytes_read == min(read_tracker.counter * cln.data_transfer_capacity, len(data))
+
+        assert await cln.read("a/foo/x", progress=read_progress_cb) == data
+        assert read_tracker.counter == data_chunks
+
         assert (await cln.get_info("a/foo/x")).size == 600
 
         # Truncation -- this write is shorter