diff --git a/.github/workflows/integration_tests.yaml b/.github/workflows/integration_tests.yaml
index 5a2fe97..1cf0f05 100644
--- a/.github/workflows/integration_tests.yaml
+++ b/.github/workflows/integration_tests.yaml
@@ -22,5 +22,7 @@ jobs:
       CI_TEST_ORCID_PASSWORD: ${{ secrets.CI_TEST_ORCID_PASSWORD }}
       CI_TEST_RAS_USERID: ${{ secrets.CI_TEST_RAS_USERID }}
       CI_TEST_RAS_PASSWORD: ${{ secrets.CI_TEST_RAS_PASSWORD }}
+      CI_TEST_RAS_2_USERID: ${{ secrets.CI_TEST_RAS_2_USERID }}
+      CI_TEST_RAS_2_PASSWORD: ${{ secrets.CI_TEST_RAS_2_PASSWORD }}
       CI_SLACK_BOT_TOKEN: ${{ secrets.CI_SLACK_BOT_TOKEN }}
       CI_SLACK_CHANNEL_ID: ${{ secrets.CI_SLACK_CHANNEL_ID }}
diff --git a/tests/app_test.py b/tests/app_test.py
index 140346b..9356a23 100644
--- a/tests/app_test.py
+++ b/tests/app_test.py
@@ -1,3 +1,4 @@
+from urllib.parse import urljoin
 import flask
 import json
 import mock
@@ -6,6 +7,9 @@
 import uuid
 import urllib
 
+from authlib.oauth2.client import OAuth2Client
+from authlib.integrations.requests_client import OAuth2Session
+
 from wts.models import RefreshToken
 from wts.resources.oauth2 import find_valid_refresh_token
 
@@ -156,6 +160,81 @@ def test_authorize_endpoint(client, test_user, db_session, auth_header):
             assert original_refresh_token == fake_tokens["idp_a"]
 
 
+def test_fetch_token_header(client, test_user, db_session, auth_header, app):
+    fake_tokens = {"default": "eyJhbGciOiJvvvv", "idp_a": "eyJhbGciOiJwwww"}
+    app_version = app.config.get("APP_VERSION")
+
+    # mock `fetch_access_token` to avoid external calls
+    mocked_response = mock.MagicMock()
+    with mock.patch.object(OAuth2Client, "fetch_token", return_value=mocked_response):
+
+        # mock `jwt.decode` to return fake data
+        now = int(time.time())
+        mocked_jwt_response = mock.MagicMock()
+        mocked_jwt_response.side_effect = [
+            # decoded id_token for IdP "default":
+            {"context": {"user": {"name": test_user.username}}},
+            # decoded refresh_token for IdP "default":
+            {
+                "jti": str(uuid.uuid4()),
+                "exp": now + 100,
+                "sub": test_user.userid,
+                "scope": ["openid", "access", "user", "test_aud"],
+                "aud": "https://localhost/user",
+                "iss": "https://localhost/user",
+            },
+            # decoded id_token for IdP "idp_a":
+            {"context": {"user": {"name": test_user.username}}},
+            # decoded refresh_token for IdP "idp_a":
+            {
+                "jti": str(uuid.uuid4()),
+                "exp": now + 100,
+                "sub": test_user.userid,
+                "scope": ["openid", "access", "user", "test_aud"],
+                "aud": "https://localhost/user",
+                "iss": "https://localhost/user",
+            },
+        ]
+        patched_jwt_decode = mock.patch("jose.jwt.decode", mocked_jwt_response)
+        patched_jwt_decode.start()
+
+        # get refresh token for IdP "default"
+        OAuth2Client.fetch_token.return_value = {
+            "refresh_token": fake_tokens["default"],
+            "id_token": "eyJhbGciOiJ",
+        }
+        fake_state = "qwerty"
+        with client.session_transaction() as session:
+            session["state"] = fake_state
+        res = client.get(
+            "/oauth2/authorize?state={}".format(fake_state), headers=auth_header
+        )
+        OAuth2Client.fetch_token.assert_called_with(
+            "https://localhost/user/oauth2/token",
+            headers={"User-Agent": f"Gen3WTS/{app_version}"},
+            state=fake_state,
+        )
+        assert res.status_code == 200, res.json
+
+        # get refresh token for IdP "idp_a"
+        OAuth2Client.fetch_token.return_value = {
+            "refresh_token": fake_tokens["idp_a"],
+            "id_token": "eyJhbGciOiJ",
+        }
+        with client.session_transaction() as session:
+            session["state"] = fake_state
+            session["idp"] = "idp_a"
+        res = client.get(
+            "/oauth2/authorize?state={}".format(fake_state), headers=auth_header
+        )
+        OAuth2Client.fetch_token.assert_called_with(
+            "https://some.data.commons/user/oauth2/token",
+            headers={"User-Agent": f"Gen3WTS/{app_version}"},
+            state=fake_state,
+        )
+        assert res.status_code == 200
+
+
 def test_authorization_url_endpoint(client):
     res = client.get("/oauth2/authorization_url?idp=idp_a")
     assert res.status_code == 302
@@ -207,6 +286,23 @@ def test_external_oidc_endpoint_with_persisted_refresh_tokens(
             assert provider["refresh_token_expiration"] == None
 
 
+def test_revoke_token_header(client, auth_header, app):
+
+    url = urljoin(app.config.get("USER_API"), "/oauth2/revoke")
+    app_version = app.config.get("APP_VERSION")
+
+    with mock.patch.object(
+        OAuth2Session,
+        "revoke_token",
+    ):
+        res = client.get("/oauth2/logout", headers=auth_header)
+        assert res.status_code == 204
+        assert res.text == ""
+        OAuth2Session.revoke_token.assert_called_with(
+            url, None, headers={"User-Agent": f"Gen3WTS/{app_version}"}
+        )
+
+
 def test_app_config(app):
     assert (
         app.config["OIDC"]["idp_a"]["redirect_uri"]
diff --git a/wts/api.py b/wts/api.py
index dabfeac..65eb1fb 100644
--- a/wts/api.py
+++ b/wts/api.py
@@ -3,6 +3,7 @@
 from cryptography.fernet import Fernet
 import flask
 from flask import Flask
+from importlib import metadata
 import json
 from urllib.parse import urlparse, urljoin
 from cdislogging import get_logger
@@ -120,6 +121,7 @@ def load_settings(app):
     app.config["SESSION_COOKIE_NAME"] = "wts"
     app.config["SESSION_COOKIE_SECURE"] = True
     app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
+    app.config["APP_VERSION"] = metadata.version("wts")
 
 
 def _log_and_jsonify_exception(e):
diff --git a/wts/blueprints/oauth2.py b/wts/blueprints/oauth2.py
index 8aa6afe..ab3beee 100644
--- a/wts/blueprints/oauth2.py
+++ b/wts/blueprints/oauth2.py
@@ -95,7 +95,10 @@ def logout_oauth():
     client = get_oauth_client(idp="default")
 
     try:
-        client.session.revoke_token(url, token)
+        app_version = flask.current_app.config.get("APP_VERSION", "0.0.0")
+        client.session.revoke_token(
+            url, token, headers={"User-Agent": f"Gen3WTS/{app_version}"}
+        )
     except APIError as e:
         msg = "could not log out, failed to revoke token: {}".format(e.message)
         return msg, 400
diff --git a/wts/resources/oauth2.py b/wts/resources/oauth2.py
index 189ec2b..2bec1a6 100644
--- a/wts/resources/oauth2.py
+++ b/wts/resources/oauth2.py
@@ -28,7 +28,12 @@ def client_do_authorize():
     if mismatched_state:
         raise AuthError("could not authorize; state did not match across auth requests")
     try:
-        tokens = client.fetch_token(token_url, **flask.request.args.to_dict())
+        app_version = flask.current_app.config.get("APP_VERSION", "0.0.0")
+        tokens = client.fetch_token(
+            token_url,
+            headers={"User-Agent": f"Gen3WTS/{app_version}"},
+            **flask.request.args.to_dict(),
+        )
         refresh_refresh_token(tokens, requested_idp, username_field)
     except KeyError as e:
         raise AuthError("error in token response: {}".format(tokens))
@@ -46,6 +51,7 @@ def find_valid_refresh_token(username, idp):
             flask.current_app.logger.info("Purging expired token {}".format(token.jti))
         else:
             has_valid = True
+    db.session.close()
     return has_valid
 
 
@@ -112,3 +118,4 @@ def refresh_refresh_token(tokens, idp, username_field):
     )
     db.session.add(new_token)
     db.session.commit()
+    db.session.close()