diff --git a/README.md b/README.md
index d40a014..bb0d863 100644
--- a/README.md
+++ b/README.md
@@ -63,6 +63,9 @@ Arguments
 | `--client-id`    | No       | OAuth2 client ID for authentication                                                                               | your_client_id                                |
 | `--client-secret`| No       | OAuth2 client secret for authentication                                                                           | your_client_secret                            |
 | `--token-url`    | No       | OAuth2 token endpoint URL for authentication                                                                      | https://auth.example.com/oauth/token          |
+| `--username`     | No       | Username for authentication                                                                                       | user                                          |
+| `--password`     | No       | Password for authentication                                                                                       | password                                      |
+| `--digest`       | No       | Use digest authentication                                                                                         |                                               |
 
 Environment Variables
 
@@ -351,6 +354,9 @@ SSE/StreamableHTTP client options:
                         OAuth2 client secret for authentication
   --token-url TOKEN_URL
                         OAuth2 token URL for authentication
+  --username USERNAME   Username for authentication
+  --password PASSWORD   Password for authentication
+  --digest              Use digest authentication
 
 stdio client options:
   args                  Any extra arguments to the command to spawn the default server. Ignored if only named servers are defined.
@@ -381,6 +387,7 @@ Examples:
   mcp-proxy http://localhost:8080/sse
   mcp-proxy --no-verify-ssl https://server.local/sse
   mcp-proxy --transport streamablehttp http://localhost:8080/mcp
+  mcp-proxy --transport streamablehttp --username user --password pass https://server.local/mcp
   mcp-proxy --headers Authorization 'Bearer YOUR_TOKEN' http://localhost:8080/sse
   mcp-proxy --client-id CLIENT_ID --client-secret CLIENT_SECRET --token-url https://auth.example.com/token http://localhost:8080/sse
   mcp-proxy --port 8080 -- your-command --arg1 value1 --arg2 value2
diff --git a/src/mcp_proxy/__main__.py b/src/mcp_proxy/__main__.py
index d99785a..d725ce2 100644
--- a/src/mcp_proxy/__main__.py
+++ b/src/mcp_proxy/__main__.py
@@ -16,6 +16,7 @@
 import typing as t
 from importlib.metadata import version
 
+from httpx import Auth, BasicAuth, DigestAuth
 from httpx_auth import OAuth2ClientCredentials
 from mcp.client.stdio import StdioServerParameters
 
@@ -54,6 +55,8 @@ def _setup_argument_parser() -> argparse.ArgumentParser:
             "  mcp-proxy http://localhost:8080/sse\n"
             "  mcp-proxy --no-verify-ssl https://server.local/sse\n"
             "  mcp-proxy --transport streamablehttp http://localhost:8080/mcp\n"
+            "  mcp-proxy --transport streamablehttp --username user --password pass "
+            "https://server.local/mcp\n"
             "  mcp-proxy --headers Authorization 'Bearer YOUR_TOKEN' http://localhost:8080/sse\n"
             "  mcp-proxy --port 8080 -- your-command --arg1 value1 --arg2 value2\n"
             "  mcp-proxy --named-server fetch 'uvx mcp-server-fetch' --port 8080\n"
@@ -125,6 +128,21 @@ def _add_arguments_to_parser(parser: argparse.ArgumentParser) -> None:
         type=str,
         help="OAuth2 token URL for authentication",
     )
+    client_group.add_argument(
+        "--username",
+        type=str,
+        help="Username for authentication",
+    )
+    client_group.add_argument(
+        "--password",
+        type=str,
+        help="Password for authentication",
+    )
+    client_group.add_argument(
+        "--digest",
+        action="store_true",
+        help="Use digest authentication",
+    )
     client_group.add_argument(
         "--verify-ssl",
         nargs="?",
@@ -301,20 +319,28 @@ def _handle_sse_client_mode(
     if api_access_token := os.getenv("API_ACCESS_TOKEN", None):
         headers["Authorization"] = f"Bearer {api_access_token}"
 
-    # Collect client credentials and token url if provided
+    # Collect client credentials if provided
     client_id = args_parsed.client_id
     client_secret = args_parsed.client_secret
     token_url = args_parsed.token_url
+    username = args_parsed.username
+    password = args_parsed.password
+    digest = args_parsed.digest
 
-    auth = (
-        OAuth2ClientCredentials(
+    auth: Auth | None = None
+    if client_id and client_secret and token_url:
+        auth = OAuth2ClientCredentials(
             client_id=client_id,
             client_secret=client_secret,
             token_url=token_url,
         )
-        if client_id and client_secret and token_url
-        else None
-    )
+    elif username and password:
+        auth = DigestAuth(username, password) if digest else BasicAuth(username, password)
+    elif username or password or digest:
+        logger.error("Both --username and --password are required")
+        sys.exit(1)
+    else:
+        auth = None
 
     if args_parsed.transport == "streamablehttp":
         asyncio.run(