diff --git a/swh/core/api/__init__.py b/swh/core/api/__init__.py
--- a/swh/core/api/__init__.py
+++ b/swh/core/api/__init__.py
@@ -24,6 +24,7 @@
 from deprecated import deprecated
 from flask import Flask, Request, Response, abort, request
 import requests
+import sentry_sdk
 from werkzeug.exceptions import HTTPException
 
 from .negotiation import Formatter as FormatterBase
@@ -415,7 +416,25 @@
 
 
 def error_handler(exception, encoder, status_code=500):
+    """Error handler to be registered using flask's error-handling decorator
+    ``app.errorhandler``.
+
+    This is used for exceptions that are expected in the normal execution flow of the
+    RPC-ed API, in which case the status code should be set to a value in the 4xx range,
+    as well as for exceptions that are unexpected (generally, a bare
+    :class:`Exception`), and for which the status code should be kept in the 5xx class.
+
+    This function only captures exceptions as sentry errors if the status code is in the
+    5xx range, as "expected exceptions" in the 4xx range are more likely to be handled
+    on the client side.
+
+    """
     logging.exception(exception)
+
+    status_class = status_code // 100
+    if status_class == 5:
+        sentry_sdk.capture_exception(exception)
+
     response = encoder(exception_to_dict(exception))
     if isinstance(exception, HTTPException):
         response.status_code = exception.code
diff --git a/swh/core/api/tests/test_rpc_client_server.py b/swh/core/api/tests/test_rpc_client_server.py
--- a/swh/core/api/tests/test_rpc_client_server.py
+++ b/swh/core/api/tests/test_rpc_client_server.py
@@ -15,6 +15,10 @@
 )
 
 
+class ExpectedException(Exception):
+    """Another exception class to distinguish error handlers"""
+
+
 # this class is used on the server part
 class RPCTest:
     @remote_api_endpoint("endpoint_url")
@@ -34,6 +38,10 @@
     def raise_exception_exc_arg(self):
         raise Exception(Exception("error"))
 
+    @remote_api_endpoint("raises_expectedexc")
+    def raise_expectedexc(self):
+        raise ExpectedException("that was expected")
+
 
 # this class is used on the client part. We cannot inherit from RPCTest
 # because the automagic metaclass based code that generates the RPCClient
@@ -58,6 +66,10 @@
     def raise_typeerror(self):
         return "data"
 
+    @remote_api_endpoint("raises_expectedexc")
+    def raise_expectedexc(self):
+        return "nothing"
+
 
 class RPCTestClient(RPCClient):
     backend_class = RPCTest2
@@ -69,6 +81,10 @@
     # which is defined in swh/core/pytest_plugin.py
     application = RPCServerApp("testapp", backend_class=RPCTest)
 
+    @application.errorhandler(ExpectedException)
+    def my_expected_error_handler(exception):
+        return error_handler(exception, encode_data_server, status_code=400)
+
     @application.errorhandler(Exception)
     def my_error_handler(exception):
         return error_handler(exception, encode_data_server)
@@ -109,10 +125,14 @@
     assert res == "egg"
 
 
-def test_api_typeerror(swh_rpc_client):
+def test_api_typeerror(swh_rpc_client, mocker):
+    mocked_capture_exception = mocker.patch("swh.core.api.sentry_sdk.capture_exception")
+
     with pytest.raises(RemoteException) as exc_info:
         swh_rpc_client.raise_typeerror()
 
+    assert mocked_capture_exception.called_once_with(TypeError("Did I pass through?"))
+
     assert exc_info.value.args[0]["type"] == "TypeError"
     assert exc_info.value.args[0]["args"] == ["Did I pass through?"]
     assert (
@@ -128,3 +148,15 @@
     assert exc_info.value.args[0]["type"] == "Exception"
     assert type(exc_info.value.args[0]["args"][0]) == Exception
     assert str(exc_info.value.args[0]["args"][0]) == "error"
+
+
+def test_api_expected_exception_no_sentry_capture(swh_rpc_client, mocker):
+    mocked_capture_exception = mocker.patch("swh.core.api.sentry_sdk.capture_exception")
+
+    with pytest.raises(RemoteException) as exc_info:
+        swh_rpc_client.raise_expectedexc()
+
+    assert not mocked_capture_exception.called
+
+    assert exc_info.value.args[0]["type"] == "ExpectedException"
+    assert exc_info.value.args[0]["args"] == ["that was expected"]