change fastmcp dependency approach

Author: joshyam-k

pyproject.toml

@@ -5,7 +5,7 @@ description = "The Posit Connect command-line interface."
 authors = [{ name = "Posit, PBC", email = "rsconnect@posit.co" }]
 license = { file = "LICENSE.md" }
 readme = { file = "README.md", content-type = "text/markdown" }
-requires-python = ">=3.10"
+requires-python = ">=3.8"
 
 dependencies = [
     "typing-extensions>=4.8.0",
@@ -14,7 +14,6 @@ dependencies = [
     "pyjwt>=2.4.0",
     "click>=8.0.0",
     "toml>=0.10; python_version < '3.11'",
-    "fastmcp==2.12.4"
 ]
 
 dynamic = ["version"]
@@ -38,8 +37,10 @@ test = [
     "setuptools_scm[toml]>=3.4",
     "twine",
     "types-Flask",
+    "fastmcp==2.12.4; python_version >= '3.10'",
 ]
 snowflake = ["snowflake-cli"]
+mcp = ["fastmcp==2.12.4; python_version >= '3.10'"]
 docs = [
     "mkdocs-material",
     "mkdocs-click",

rsconnect/main.py

@@ -404,13 +404,20 @@ def version():
 
 @cli.command(help="Start the MCP server")
 def mcp_server():
-    from fastmcp import FastMCP
-    from fastmcp.exceptions import ToolError
+    try:
+        from fastmcp import FastMCP
+        from fastmcp.exceptions import ToolError
+    except ImportError:
+        raise RSConnectException(
+            "The fastmcp package is required for MCP server functionality. "
+            "Install it with: pip install rsconnect-python[mcp]"
+        )
 
     mcp = FastMCP("Connect MCP")
 
     # Discover all commands at startup
     from .mcp_deploy_context import discover_all_commands
+
     all_commands_info = discover_all_commands(cli)
 
     @mcp.tool()
@@ -431,10 +438,7 @@ def get_command_info(
             parts = command_path.strip().split()
             if not parts:
                 available_commands = list(all_commands_info["commands"].keys())
-                return {
-                    "error": "Command path cannot be empty",
-                    "available_commands": available_commands
-                }
+                return {"error": "Command path cannot be empty", "available_commands": available_commands}
 
             current_info = all_commands_info
             current_path = []
@@ -451,11 +455,8 @@ def get_command_info(
                 # try to return useful messaging for invalid subcommands
                 if part not in current_info["commands"]:
                     available = list(current_info["commands"].keys())
-                    path_str = ' '.join(current_path) if current_path else "top level"
-                    return {
-                        "error": f"Command '{part}' not found in {path_str}",
-                        "available_commands": available
-                    }
+                    path_str = " ".join(current_path) if current_path else "top level"
+                    return {"error": f"Command '{part}' not found in {path_str}", "available_commands": available}
 
                 current_info = current_info["commands"][part]
                 current_path.append(part)
@@ -467,7 +468,7 @@ def get_command_info(
                     "name": current_info.get("name", parts[-1]),
                     "description": current_info.get("description"),
                     "available_subcommands": list(current_info["commands"].keys()),
-                    "message": f"The '{' '.join(parts)}' command requires a subcommand."
+                    "message": f"The '{' '.join(parts)}' command requires a subcommand.",
                 }
             else:
                 return {
@@ -476,7 +477,7 @@ def get_command_info(
                     "name": current_info.get("name", parts[-1]),
                     "description": current_info.get("description"),
                     "parameters": current_info.get("parameters", []),
-                    "shell": "bash"
+                    "shell": "bash",
                 }
         except Exception as e:
             raise ToolError(f"Failed to retrieve command info: {str(e)}")

rsconnect/mcp_deploy_context.py

@@ -15,7 +15,7 @@ def extract_parameter_info(param: click.Parameter) -> Dict[str, Any]:
 
     if isinstance(param, click.Option) and param.opts:
         # Use the longest option name (usually the full form without dashes)
-        mcp_arg_name = max(param.opts, key=len).lstrip('-').replace('-', '_')
+        mcp_arg_name = max(param.opts, key=len).lstrip("-").replace("-", "_")
         info["name"] = mcp_arg_name
         info["cli_flags"] = param.opts
         info["param_type"] = "option"
@@ -25,7 +25,7 @@ def extract_parameter_info(param: click.Parameter) -> Dict[str, Any]:
             info["param_type"] = "argument"
 
     # extract help text for added context
-    help_text = getattr(param, 'help', None)
+    help_text = getattr(param, "help", None)
     if help_text:
         info["description"] = help_text
 
@@ -36,7 +36,7 @@ def extract_parameter_info(param: click.Parameter) -> Dict[str, Any]:
             info["default"] = param.default or False
 
         # choices
-        elif param.type and hasattr(param.type, 'choices'):
+        elif param.type and hasattr(param.type, "choices"):
             info["type"] = "string"
             info["choices"] = list(param.type.choices)
 
@@ -75,11 +75,7 @@ def extract_parameter_info(param: click.Parameter) -> Dict[str, Any]:
 
 def discover_single_command(cmd: click.Command) -> Dict[str, Any]:
     """Discover a single command and its parameters."""
-    cmd_info = {
-        "name": cmd.name,
-        "description": cmd.help,
-        "parameters": []
-    }
+    cmd_info = {"name": cmd.name, "description": cmd.help, "parameters": []}
 
     for param in cmd.params:
         if param.name in ["verbose", "v"]:
@@ -93,11 +89,7 @@ def discover_single_command(cmd: click.Command) -> Dict[str, Any]:
 
 def discover_command_group(group: click.Group) -> Dict[str, Any]:
     """Discover all commands in a command group and their parameters."""
-    result = {
-        "name": group.name,
-        "description": group.help,
-        "commands": {}
-    }
+    result = {"name": group.name, "description": group.help, "commands": {}}
 
     for cmd_name, cmd in group.commands.items():
         if isinstance(cmd, click.Group):

tests/test_mcp_deploy_context.py

@@ -1,9 +1,14 @@
 """Tests for MCP deploy context."""
 
-from unittest import TestCase
+import pytest
 
-from rsconnect.main import cli
-from rsconnect.mcp_deploy_context import discover_all_commands
+# Skip entire module if fastmcp is not available (requires Python 3.10+)
+pytest.importorskip("fastmcp", reason="fastmcp library not installed (requires Python 3.10+)")
+
+from unittest import TestCase  # noqa
+
+from rsconnect.main import cli  # noqa
+from rsconnect.mcp_deploy_context import discover_all_commands  # noqa
 
 
 class TestDiscoverAllCommands(TestCase):
@@ -16,7 +21,20 @@ def test_discover_rsconnect_cli(self):
     def test_top_level_commands(self):
         result = discover_all_commands(cli)
 
-        expected = ["version", "mcp-server", "add", "list", "remove", "details", "info", "deploy", "write-manifest", "content", "system", "bootstrap"]
+        expected = [
+            "version",
+            "mcp-server",
+            "add",
+            "list",
+            "remove",
+            "details",
+            "info",
+            "deploy",
+            "write-manifest",
+            "content",
+            "system",
+            "bootstrap",
+        ]
         for cmd in expected:
             self.assertIn(cmd, result["commands"])
 
@@ -28,7 +46,22 @@ def test_deploy_subcommands(self):
         result = discover_all_commands(cli)
 
         deploy = result["commands"]["deploy"]
-        expected = ["notebook", "voila", "manifest", "quarto", "tensorflow", "html", "api", "flask", "fastapi", "dash", "streamlit", "bokeh", "shiny", "gradio"]
+        expected = [
+            "notebook",
+            "voila",
+            "manifest",
+            "quarto",
+            "tensorflow",
+            "html",
+            "api",
+            "flask",
+            "fastapi",
+            "dash",
+            "streamlit",
+            "bokeh",
+            "shiny",
+            "gradio",
+        ]
         for subcmd in expected:
             self.assertIn(subcmd, deploy["commands"])