diff --git a/docs/source/configurable.rst b/docs/source/configurable.rst
index 69294ef62..35ed8fba4 100644
--- a/docs/source/configurable.rst
+++ b/docs/source/configurable.rst
@@ -101,6 +101,7 @@ such as ``show_100_pass_modules``.
 * ``deprefix`` - Remove the prompt from the start of the output (some models return the prompt as part of their output)
 * ``seed`` - An optional random seed
 * ``eval_threshold`` - At what point in the 0..1 range output by detectors does a result count as a successful attack / hit
+* ``user_agent`` - What HTTP user agent string should garak use? ``{version}`` can be used to signify where garak version ID should go
 
 ``plugins`` config items
 """"""""""""""""""""""""
diff --git a/garak/_config.py b/garak/_config.py
index f420d5484..7e3480ae3 100644
--- a/garak/_config.py
+++ b/garak/_config.py
@@ -23,7 +23,7 @@
 
 DICT_CONFIG_AFTER_LOAD = False
 
-version = -1  # eh why this is here? hm. who references it
+from garak import __version__ as version
 
 system_params = (
     "verbose narrow_output parallel_requests parallel_attempts skip_unknown".split()
@@ -144,14 +144,66 @@ def _load_yaml_config(settings_filenames) -> dict:
 
 
 def _store_config(settings_files) -> None:
-    global system, run, plugins, reporting
+    global system, run, plugins, reporting, version
     settings = _load_yaml_config(settings_files)
     system = _set_settings(system, settings["system"])
     run = _set_settings(run, settings["run"])
+    run.user_agent = run.user_agent.replace("{version}", version)
     plugins = _set_settings(plugins, settings["plugins"])
     reporting = _set_settings(reporting, settings["reporting"])
 
 
+# not my favourite solution in this module, but if
+# _config.set_http_lib_agents() to be predicated on a param instead of
+# a _config.run value (i.e. user_agent) - which it needs to be if it can be
+# used when the values are popped back to originals - then a separate way
+# of passing the UA string to _garak_user_agent() needs to exist, outside of
+# _config.run.user_agent
+REQUESTS_AGENT = ""
+
+
+def _garak_user_agent(dummy=None):
+    return str(REQUESTS_AGENT)
+
+
+def set_all_http_lib_agents(agent_string):
+    set_http_lib_agents(
+        {"requests": agent_string, "httpx": agent_string, "aiohttp": agent_string}
+    )
+
+
+def set_http_lib_agents(agent_strings: dict):
+
+    global REQUESTS_AGENT
+
+    if "requests" in agent_strings:
+        from requests import utils
+
+        REQUESTS_AGENT = agent_strings["requests"]
+        utils.default_user_agent = _garak_user_agent
+    if "httpx" in agent_strings:
+        import httpx
+
+        httpx._client.USER_AGENT = agent_strings["httpx"]
+    if "aiohttp" in agent_strings:
+        import aiohttp
+
+        aiohttp.client_reqrep.SERVER_SOFTWARE = agent_strings["aiohttp"]
+
+
+def get_http_lib_agents():
+    from requests import utils
+    import httpx
+    import aiohttp
+
+    agent_strings = {}
+    agent_strings["requests"] = utils.default_user_agent
+    agent_strings["httpx"] = httpx._client.USER_AGENT
+    agent_strings["aiohttp"] = aiohttp.client_reqrep.SERVER_SOFTWARE
+
+    return agent_strings
+
+
 def load_base_config() -> None:
     global loaded
     settings_files = [str(transient.package_dir / "resources" / "garak.core.yaml")]
@@ -193,6 +245,7 @@ def load_config(
 
     logging.debug("Loading configs from: %s", ",".join(settings_files))
     _store_config(settings_files=settings_files)
+
     if DICT_CONFIG_AFTER_LOAD:
         _lock_config_as_dict()
     loaded = True
diff --git a/garak/cli.py b/garak/cli.py
index 5894ce0dd..02d0b9833 100644
--- a/garak/cli.py
+++ b/garak/cli.py
@@ -10,13 +10,12 @@ def main(arguments=None) -> None:
     """Main entry point for garak runs invoked from the CLI"""
     import datetime
 
-    from garak import __version__, __description__
+    from garak import __description__
     from garak import _config
     from garak.exception import GarakException
 
     _config.transient.starttime = datetime.datetime.now()
     _config.transient.starttime_iso = _config.transient.starttime.isoformat()
-    _config.version = __version__
 
     if arguments is None:
         arguments = []
@@ -255,6 +254,7 @@ def main(arguments=None) -> None:
 
     # load site config before loading CLI config
     _cli_config_supplied = args.config is not None
+    prior_user_agents = _config.get_http_lib_agents()
     _config.load_config(run_config_filename=args.config)
 
     # extract what was actually passed on CLI; use a masking argparser
@@ -554,3 +554,5 @@ def main(arguments=None) -> None:
     except (ValueError, GarakException) as e:
         logging.exception(e)
         print(e)
+
+    _config.set_http_lib_agents(prior_user_agents)
diff --git a/garak/harnesses/base.py b/garak/harnesses/base.py
index 79e9c63a3..898684bf6 100644
--- a/garak/harnesses/base.py
+++ b/garak/harnesses/base.py
@@ -64,6 +64,13 @@ def _load_buffs(self, buff_names: List) -> None:
                     logging.warning(err_msg)
                     continue
 
+    def _start_run_hook(self):
+        self._http_lib_user_agents = _config.get_http_lib_agents()
+        _config.set_all_http_lib_agents(_config.run.user_agent)
+
+    def _end_run_hook(self):
+        _config.set_http_lib_agents(self._http_lib_user_agents)
+
     def run(self, model, probes, detectors, evaluator, announce_probe=True) -> None:
         """Core harness method
 
@@ -92,6 +99,8 @@ def run(self, model, probes, detectors, evaluator, announce_probe=True) -> None:
                 print(msg)
             raise ValueError(msg)
 
+        self._start_run_hook()
+
         for probe in probes:
             logging.debug("harness: probe start for %s", probe.probename)
             if not probe:
@@ -135,4 +144,6 @@ def run(self, model, probes, detectors, evaluator, announce_probe=True) -> None:
             else:
                 evaluator.evaluate(attempt_results)
 
+        self._end_run_hook()
+
         logging.debug("harness: probe list iteration completed")
diff --git a/garak/resources/garak.core.yaml b/garak/resources/garak.core.yaml
index 98a1fa2e9..a3d948935 100644
--- a/garak/resources/garak.core.yaml
+++ b/garak/resources/garak.core.yaml
@@ -13,6 +13,7 @@ run:
   eval_threshold: 0.5
   generations: 5
   probe_tags:
+  user_agent: "garak/{version} (LLM vulnerability scanner https://garak.ai)"
 
 plugins:
   model_type:
diff --git a/pyproject.toml b/pyproject.toml
index 681ffc72b..e7d0ca3dc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -86,7 +86,8 @@ tests = [
   "pytest>=8.0",
   "requests-mock==1.12.1",
   "respx>=0.21.1",
-  "pytest-cov>=5.0.0"
+  "pytest-cov>=5.0.0",
+  "pytest_httpserver>=1.1.0"
 ]
 lint = [
   "black==24.4.2",
diff --git a/requirements.txt b/requirements.txt
index 8eb5a3ee0..8b30110a1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -41,6 +41,7 @@ pytest>=8.0
 requests-mock==1.12.1
 respx>=0.21.1
 pytest-cov>=5.0.0
+pytest_httpserver>=1.1.0
 # lint
 black==24.4.2
 pylint>=3.1.0
diff --git a/tests/generators/test_rest.py b/tests/generators/test_rest.py
index 932473ba8..1fcf67175 100644
--- a/tests/generators/test_rest.py
+++ b/tests/generators/test_rest.py
@@ -14,6 +14,7 @@
 
 @pytest.fixture
 def set_rest_config():
+    _config.run.user_agent = "test user agent, garak.ai"
     _config.plugins.generators["rest"] = {}
     _config.plugins.generators["rest"]["RestGenerator"] = {
         "name": DEFAULT_NAME,
diff --git a/tests/test_config.py b/tests/test_config.py
index 3892e6774..60d675562 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -4,14 +4,15 @@
 import importlib
 import json
 import os
+from pathlib import Path
+import pytest
 import re
 import shutil
 import sys
 import tempfile
 
-import pytest
+from pytest_httpserver import HTTPServer
 
-from pathlib import Path
 from garak import _config
 import garak.cli
 
@@ -764,3 +765,63 @@ def test_nested():
 
     _config.plugins.generators["a"]["b"]["c"]["d"] = "e"
     assert _config.plugins.generators["a"]["b"]["c"]["d"] == "e"
+
+
+def test_get_user_agents():
+    agents = _config.get_http_lib_agents()
+    assert isinstance(agents, dict)
+
+
+AGENT_TEST = "garak/9 - only simple tailors edition"
+
+
+def test_set_agents():
+    from requests import utils
+    import httpx
+    import aiohttp
+
+    _config.set_all_http_lib_agents(AGENT_TEST)
+
+    assert str(utils.default_user_agent()) == AGENT_TEST
+    assert httpx._client.USER_AGENT == AGENT_TEST
+    assert aiohttp.client_reqrep.SERVER_SOFTWARE == AGENT_TEST
+
+def httpserver():
+   return HTTPServer()
+
+
+def test_agent_is_used_requests(httpserver: HTTPServer):
+    import requests
+
+    _config.set_http_lib_agents({"requests": AGENT_TEST})
+    httpserver.expect_request(
+        "/", headers={"User-Agent": AGENT_TEST}
+    ).respond_with_data("")
+    assert requests.get(httpserver.url_for("/")).status_code == 200
+
+
+def test_agent_is_used_httpx(httpserver: HTTPServer):
+    import httpx
+
+    _config.set_http_lib_agents({"httpx": AGENT_TEST})
+    httpserver.expect_request(
+        "/", headers={"User-Agent": AGENT_TEST}
+    ).respond_with_data("")
+    assert httpx.get(httpserver.url_for("/")).status_code == 200
+
+
+def test_agent_is_used_aiohttp(httpserver: HTTPServer):
+    import aiohttp
+    import asyncio
+
+    _config.set_http_lib_agents({"aiohttp": AGENT_TEST})
+
+    async def main():
+        async with aiohttp.ClientSession() as session:
+            async with session.get(httpserver.url_for("/")) as response:
+                html = await response.text()
+
+    httpserver.expect_request(
+        "/", headers={"User-Agent": AGENT_TEST}
+    ).respond_with_data("")
+    asyncio.run(main())