diff --git a/swh/counters/api/server.py b/swh/counters/api/server.py
--- a/swh/counters/api/server.py
+++ b/swh/counters/api/server.py
@@ -29,7 +29,10 @@
     handler = logging.StreamHandler()
     app.logger.addHandler(handler)
 
+    app.config["counters"] = get_counters(**config["counters"])
+
     app.add_url_rule("/", "index", index)
+    app.add_url_rule("/metrics", "metrics", get_metrics)
 
     return app
 
@@ -84,3 +87,32 @@
         app = make_app(api_cfg)
 
     return app
+
+
+def get_metrics():
+    """expose the counters values in a prometheus format
+
+        detailed format:
+        # HELP swh_archive_object_total Software Heritage Archive object counters
+        # TYPE swh_archive_object_total gauge
+        swh_archive_object_total{col="value",object_type="<collection>"} <value>
+        ...
+    """
+
+    response = [
+        "# HELP swh_archive_object_total Software Heritage Archive object counters",
+        "# TYPE swh_archive_object_total gauge",
+    ]
+    counters = app.config["counters"]
+
+    for collection in counters.get_counters():
+        collection_name = collection.decode("utf-8")
+        value = counters.get_count(collection)
+        line = 'swh_archive_object_total{col="value", object_type="%s"} %s' % (
+            collection_name,
+            value,
+        )
+        response.append(line)
+    response.append("")
+
+    return "\n".join(response)
diff --git a/swh/counters/interface.py b/swh/counters/interface.py
--- a/swh/counters/interface.py
+++ b/swh/counters/interface.py
@@ -26,3 +26,7 @@
     def get_count(self, collection: str) -> int:
         """Return the number of keys for the provided collection"""
         ...
+
+    @remote_api_endpoint("counters")
+    def get_counters(self) -> Iterable[str]:
+        """Return the list of managed counters"""
diff --git a/swh/counters/redis.py b/swh/counters/redis.py
--- a/swh/counters/redis.py
+++ b/swh/counters/redis.py
@@ -55,3 +55,6 @@
 
     def get_count(self, collection: str) -> int:
         return self.redis_client.pfcount(collection)
+
+    def get_counters(self) -> Iterable[str]:
+        return self.redis_client.keys()
diff --git a/swh/counters/tests/conftest.py b/swh/counters/tests/conftest.py
--- a/swh/counters/tests/conftest.py
+++ b/swh/counters/tests/conftest.py
@@ -6,6 +6,7 @@
 import logging
 
 import pytest
+from redis import Redis as RedisClient
 
 logger = logging.getLogger(__name__)
 
@@ -24,3 +25,11 @@
     return JOURNAL_OBJECTS_CONFIG_TEMPLATE.format(
         broker=kafka_server, group_id="test-consumer", prefix=kafka_prefix
     )
+
+
+@pytest.fixture
+def local_redis(redis_proc):
+    yield redis_proc
+    # Cleanup redis between 2 tests
+    rc = RedisClient(host=redis_proc.host, port=redis_proc.port)
+    rc.flushall()
diff --git a/swh/counters/tests/test_redis.py b/swh/counters/tests/test_redis.py
--- a/swh/counters/tests/test_redis.py
+++ b/swh/counters/tests/test_redis.py
@@ -4,12 +4,10 @@
 # See top-level LICENSE file for more information
 
 import pytest
-from pytest_redis import factories
+from redis import Redis as RedisClient
 
 from swh.counters.redis import DEFAULT_REDIS_PORT, Redis
 
-local_redis = factories.redis_proc(host="localhost")
-
 
 def test__redis__constructor():
     r = Redis("fakehost")
@@ -66,3 +64,17 @@
     assert 1 == r.get_count("c2")
     assert 2 == r.get_count("c3")
     assert 0 == r.get_count("c4")
+
+
+def test__redis__collections(local_redis):
+    client = RedisClient(host=local_redis.host, port=local_redis.port)
+    client.pfadd("counter1", b"k1")
+    client.pfadd("counter2", b"k2")
+
+    r = Redis("%s:%d" % (local_redis.host, local_redis.port))
+
+    counters = r.get_counters()
+
+    assert 2 == len(counters)
+    assert b"counter1" in counters
+    assert b"counter2" in counters
diff --git a/swh/counters/tests/test_server.py b/swh/counters/tests/test_server.py
--- a/swh/counters/tests/test_server.py
+++ b/swh/counters/tests/test_server.py
@@ -3,9 +3,11 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
+import re
 from typing import Any, Dict
 
 import pytest
+from redis import Redis as RedisClient
 import yaml
 
 from swh.core.api import RPCServerApp
@@ -15,12 +17,12 @@
 
 def teardown_function():
     # Ensure there is no configuration loaded from a previous test
-    server.api = None
+    server.app = None
 
 
 @pytest.fixture
 def swh_counters_server_config() -> Dict[str, Any]:
-    return {"counters": {"cls": "redis", "hosts": "redis",}}
+    return {"counters": {"cls": "redis", "host": "redis",}}
 
 
 @pytest.fixture
@@ -97,3 +99,47 @@
 
     assert 200 == r.status_code
     assert b"SWH Counters" in r.get_data()
+
+
+def test_server_metrics(local_redis, tmp_path, monkeypatch):
+    """Test the metrics generation"""
+
+    rc = RedisClient(host=local_redis.host, port=local_redis.port)
+    data = {
+        "col1": 1,
+        "col2": 4,
+        "col3": 6,
+        "col4": 10,
+    }
+
+    for coll in data.keys():
+        for i in range(0, data[coll]):
+            rc.pfadd(coll, i)
+
+    cfg = {
+        "counters": {"cls": "redis", "host": f"{local_redis.host}:{local_redis.port}"}
+    }
+    _environment_config_file(tmp_path, monkeypatch, cfg)
+
+    app = make_app_from_configfile()
+    app.config["TESTING"] = True
+    tc = app.test_client()
+
+    r = tc.get("/metrics")
+
+    assert 200 == r.status_code
+
+    response = r.get_data().decode("utf-8")
+
+    assert "HELP" in response
+    assert "TYPE" in response
+
+    for collection in data.keys():
+        obj_type = f'object_type="{collection}"'
+        assert obj_type in response
+
+        pattern = r'swh_archive_object_total{col="value", object_type="%s"} (\d+)' % (
+            collection
+        )
+        m = re.search(pattern, response)
+        assert data[collection] == int(m.group(1))