diff --git a/cli.py b/cli.py
index c21acfa..64addf5 100644
--- a/cli.py
+++ b/cli.py
@@ -3,9 +3,12 @@ import json
 import click
 
 from query_performance_gauge import run_measuring_session
-
+from utils import compose_config
 
 @click.command()
-@click.option("--config", required=True, type=click.File())
-def measure_performance(config):
-    run_measuring_session(json.load(config))
+@click.option("--config", type=click.File())
+@click.option("--credentials", type=click.File())
+@click.option("--queries", type=click.File())
+def measure_performance(config, credentials, queries):
+    config = compose_config(config, credentials, queries)
+    run_measuring_session(config)
diff --git a/utils.py b/utils.py
new file mode 100644
index 0000000..89cb246
--- /dev/null
+++ b/utils.py
@@ -0,0 +1,29 @@
+from typing import Union
+from io import TextIOWrapper
+import json
+
+
+def compose_config(
+    config: Union[TextIOWrapper, None],
+    credentials: Union[TextIOWrapper, None],
+    queries: Union[TextIOWrapper, None],
+) -> dict:
+    """
+    Receive the CLI arguments and compose a session config.
+
+    :param config: file pointer to a full config file.
+    :param credentials: file pointer to a credentials file.
+    :param queries: file pointer to a queries file.
+    :return: a dict with the composed configuration.
+    """
+
+    if config is not None:
+        return json.load(config)
+
+    if credentials is None or queries is None:
+        raise ValueError(
+            "You need to provide both --credentials and --queries arguments."
+        )
+
+    # Merge both into one dict so it follows the same structure as a full config file
+    return {**json.load(credentials), **json.load(queries)}