diff --git a/tests/test_connexion_extractors.py b/tests/test_connexion_extractors.py
new file mode 100644
index 0000000..35db8cf
--- /dev/null
+++ b/tests/test_connexion_extractors.py
@@ -0,0 +1,82 @@
+"""Request and response info extraction for the connexion backend (issue #137)."""
+from types import SimpleNamespace
+
+import pytest
+from helpers.imports import undo_imports_from_package
+
+
+@pytest.fixture
+def connexion_extractors():
+    import json_logging
+    from json_logging.framework import connexion as connexion_framework
+
+    yield json_logging, connexion_framework
+    undo_imports_from_package("json_logging")
+
+
+def _request(**overrides):
+    values = dict(
+        authorization=None,
+        headers={"X-Present": "yes"},
+        environ={"SERVER_PROTOCOL": "HTTP/1.1", "REMOTE_PORT": "5555"},
+        path="/hello",
+        content_length=12,
+        method="POST",
+        remote_addr="10.0.0.1",
+    )
+    values.update(overrides)
+    return SimpleNamespace(**values)
+
+
+def test_init_request_instrument_rejects_non_connexion_app(connexion_extractors):
+    json_logging, _ = connexion_extractors
+    json_logging.init_connexion()
+
+    with pytest.raises(RuntimeError, match="not a valid connexion"):
+        json_logging.init_request_instrument(SimpleNamespace(app=object()))
+
+
+def test_remote_user_defaults_to_empty_value(connexion_extractors):
+    json_logging, framework = connexion_extractors
+
+    assert framework.ConnexionRequestInfoExtractor().get_remote_user(_request()) == json_logging.EMPTY_VALUE
+
+
+def test_remote_user_is_the_basic_auth_username(connexion_extractors):
+    _, framework = connexion_extractors
+    request = _request(authorization=SimpleNamespace(username="alice"))
+
+    assert framework.ConnexionRequestInfoExtractor().get_remote_user(request) == "alice"
+
+
+def test_header_lookup_falls_back_to_default(connexion_extractors):
+    _, framework = connexion_extractors
+    extractor = framework.ConnexionRequestInfoExtractor()
+
+    assert extractor.get_http_header(_request(), "X-Present") == "yes"
+    assert extractor.get_http_header(_request(), "X-Missing", "fallback") == "fallback"
+    assert extractor.get_http_header(object(), "X-Missing", "fallback") == "fallback"
+
+
+def test_request_fields_are_read_from_the_request(connexion_extractors):
+    _, framework = connexion_extractors
+    extractor = framework.ConnexionRequestInfoExtractor()
+    request = _request()
+
+    assert extractor.get_protocol(request) == "HTTP/1.1"
+    assert extractor.get_path(request) == "/hello"
+    assert extractor.get_content_length(request) == 12
+    assert extractor.get_method(request) == "POST"
+    assert extractor.get_remote_ip(request) == "10.0.0.1"
+    assert extractor.get_remote_port(request) == "5555"
+
+
+def test_response_fields_are_read_from_the_response(connexion_extractors):
+    _, framework = connexion_extractors
+    extractor = framework.ConnexionResponseInfoExtractor()
+    response = SimpleNamespace(
+        status_code=201, calculate_content_length=lambda: 42, content_type="application/json")
+
+    assert extractor.get_status_code(response) == 201
+    assert extractor.get_response_size(response) == 42
+    assert extractor.get_content_type(response) == "application/json"
diff --git a/tests/test_flask_extractors.py b/tests/test_flask_extractors.py
new file mode 100644
index 0000000..f48d583
--- /dev/null
+++ b/tests/test_flask_extractors.py
@@ -0,0 +1,94 @@
+"""Request and response info extraction for the flask and connexion backends (issue #137)."""
+import base64
+import json
+import logging
+from types import SimpleNamespace
+
+import flask
+import pytest
+from helpers.handler import FormattedMessageCollectorHandler
+from helpers.imports import undo_imports_from_package
+
+
+@pytest.fixture
+def flask_app_and_request_handler():
+    import json_logging
+    from json_logging.formatters import JSONRequestLogFormatter
+
+    app = flask.Flask(__name__)
+    request_logger = logging.getLogger("flask-request-logger")
+    handler = FormattedMessageCollectorHandler()
+    handler.setFormatter(JSONRequestLogFormatter())
+
+    json_logging.init_flask(enable_json=True)
+    json_logging.init_request_instrument(app)
+    request_logger.addHandler(handler)
+
+    @app.route("/hello")
+    def hello():
+        return {"hello": "world"}
+
+    yield app, handler
+
+    request_logger.removeHandler(handler)
+    undo_imports_from_package("json_logging")
+
+
+def test_flask_request_log_has_request_and_response_details(flask_app_and_request_handler):
+    app, handler = flask_app_and_request_handler
+
+    response = app.test_client().get("/hello", headers={"X-Correlation-Id": "abc-def"})
+
+    assert response.status_code == 200
+    msg = json.loads(handler.messages[0])
+    assert msg["method"] == "GET"
+    assert msg["request"] == "/hello"
+    assert msg["protocol"] == "HTTP/1.1"
+    assert msg["correlation_id"] == "abc-def"
+    assert msg["response_status"] == 200
+    assert msg["response_content_type"] == "application/json"
+    assert msg["response_size_b"] == len(response.data)
+    assert msg["remote_user"] == "-"
+
+
+def test_flask_request_log_has_basic_auth_user(flask_app_and_request_handler):
+    app, handler = flask_app_and_request_handler
+    token = base64.b64encode(b"alice:secret").decode()
+
+    app.test_client().get("/hello", headers={"Authorization": "Basic " + token})
+
+    assert json.loads(handler.messages[0])["remote_user"] == "alice"
+
+
+def test_flask_init_request_instrument_rejects_non_flask_app(flask_app_and_request_handler):
+    import json_logging
+
+    with pytest.raises(RuntimeError, match="not a valid flask"):
+        json_logging.init_request_instrument(object())
+
+
+def test_flask_extractor_outside_request_context_has_no_current_request(flask_app_and_request_handler):
+    from json_logging.framework.flask import FlaskRequestInfoExtractor
+
+    assert FlaskRequestInfoExtractor.get_current_request() is None
+
+
+def test_flask_extractor_header_lookup_falls_back_to_default(flask_app_and_request_handler):
+    from json_logging.framework.flask import FlaskRequestInfoExtractor
+
+    extractor = FlaskRequestInfoExtractor()
+    request = SimpleNamespace(headers={"X-Present": "yes"})
+
+    assert extractor.get_http_header(request, "X-Present") == "yes"
+    assert extractor.get_http_header(request, "X-Missing", "fallback") == "fallback"
+    # an object without usable headers must not raise
+    assert extractor.get_http_header(object(), "X-Missing", "fallback") == "fallback"
+
+
+def test_flask_extractor_correlation_id_outside_request_context_is_none(flask_app_and_request_handler):
+    from json_logging.framework.flask import FlaskRequestInfoExtractor
+
+    extractor = FlaskRequestInfoExtractor()
+
+    extractor.set_correlation_id(None, "ignored")  # no app context: must not raise
+    assert extractor.get_correlation_id_in_request_context(None) is None