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 = "[email protected]" }]
 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"]
@@ -40,6 +39,7 @@ test = [
     "types-Flask",
 ]
 snowflake = ["snowflake-cli"]
+mcp = ["fastmcp==2.12.4"]
 docs = [
     "mkdocs-material",
     "mkdocs-click",

rsconnect/main.py

@@ -404,8 +404,14 @@ 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")