Fix and centralize CLI path resolution (#1590)

Author: jlowin

.pre-commit-config.yaml

@@ -25,7 +25,7 @@ repos:
   - repo: local
     hooks:
       - id: ty
-        name: type check
+        name: ty check
         entry: uv run ty check
         language: system
         types: [python]
@@ -37,4 +37,5 @@ repos:
     rev: v6.0.0
     hooks:
       - id: no-commit-to-branch
+        name: prevent commits to main
         args: [--branch, main]

src/fastmcp/cli/claude.py

@@ -6,6 +6,7 @@
 from pathlib import Path
 from typing import Any
 
+from fastmcp.utilities.cli import build_uv_run_args
 from fastmcp.utilities.logging import get_logger
 
 logger = get_logger(__name__)
@@ -89,20 +90,11 @@ def update_claude_config(
             else:
                 env_vars = existing_env
 
-        # Build uv run command
-        args = ["run"]
-
-        # Collect all packages in a set to deduplicate
-        packages = {"fastmcp"}
-        if with_packages:
-            packages.update(pkg for pkg in with_packages if pkg)
-
-        # Add all packages with --with
-        for pkg in sorted(packages):
-            args.extend(["--with", pkg])
-
-        if with_editable:
-            args.extend(["--with-editable", str(with_editable)])
+        # Build uv run command using centralized function
+        args = build_uv_run_args(
+            with_editable=with_editable,
+            with_packages=with_packages,
+        )
 
         # Convert file path to absolute before adding to command
         # Split off any :object suffix first

src/fastmcp/cli/cli.py

@@ -19,6 +19,7 @@
 from fastmcp.cli import run as run_module
 from fastmcp.cli.install import install_app
 from fastmcp.server.server import FastMCP
+from fastmcp.utilities.cli import build_uv_command
 from fastmcp.utilities.inspect import FastMCPInfo, inspect_fastmcp
 from fastmcp.utilities.logging import get_logger
 
@@ -57,46 +58,8 @@ def _parse_env_var(env_var: str) -> tuple[str, str]:
     return key.strip(), value.strip()
 
 
-def _build_uv_command(
-    server_spec: str,
-    with_editable: Path | None = None,
-    with_packages: list[str] | None = None,
-    no_banner: bool = False,
-    python_version: str | None = None,
-    with_requirements: Path | None = None,
-    project: Path | None = None,
-) -> list[str]:
-    """Build the uv run command that runs a MCP server through mcp run."""
-    cmd = ["uv", "run"]
-
-    # Add Python version if specified
-    if python_version:
-        cmd.extend(["--python", python_version])
-
-    # Add project if specified
-    if project:
-        cmd.extend(["--project", str(project)])
-
-    cmd.extend(["--with", "fastmcp"])
-
-    if with_editable:
-        cmd.extend(["--with-editable", str(with_editable)])
-
-    if with_packages:
-        for pkg in with_packages:
-            if pkg:
-                cmd.extend(["--with", pkg])
-
-    if with_requirements:
-        cmd.extend(["--with-requirements", str(with_requirements)])
-
-    # Add mcp run command
-    cmd.extend(["fastmcp", "run", server_spec])
-
-    if no_banner:
-        cmd.append("--no-banner")
-
-    return cmd
+# The _build_uv_command function has been moved to cli/utils.py
+# and is now imported as build_uv_command
 
 
 @app.command
@@ -302,16 +265,18 @@ async def dev(
         if inspector_version:
             inspector_cmd += f"@{inspector_version}"
 
-        uv_cmd = _build_uv_command(
+        uv_cmd = build_uv_command(
             server_spec,
-            with_editable,
-            with_packages,
-            no_banner=True,
+            with_editable=with_editable,
+            with_packages=with_packages,
             python_version=python,
             with_requirements=with_requirements,
             project=project,
         )
 
+        # Add --no-banner flag for dev command
+        uv_cmd.append("--no-banner")
+
         # Run the MCP Inspector command with shell=True on Windows
         shell = sys.platform == "win32"
         process = subprocess.run(

src/fastmcp/cli/install/claude_code.py

@@ -9,6 +9,7 @@
 import cyclopts
 from rich import print
 
+from fastmcp.utilities.cli import build_uv_run_args
 from fastmcp.utilities.logging import get_logger
 
 from .shared import process_common_args
@@ -106,31 +107,14 @@ def install_claude_code(
         )
         return False
 
-    # Build uv run command
-    args = ["run"]
-
-    # Add Python version if specified
-    if python_version:
-        args.extend(["--python", python_version])
-
-    # Add project if specified
-    if project:
-        args.extend(["--project", str(project)])
-
-    # Collect all packages in a set to deduplicate
-    packages = {"fastmcp"}
-    if with_packages:
-        packages.update(pkg for pkg in with_packages if pkg)
-
-    # Add all packages with --with
-    for pkg in sorted(packages):
-        args.extend(["--with", pkg])
-
-    if with_editable:
-        args.extend(["--with-editable", str(with_editable)])
-
-    if with_requirements:
-        args.extend(["--with-requirements", str(with_requirements)])
+    # Build uv run command using centralized function
+    args = build_uv_run_args(
+        with_editable=with_editable,
+        with_packages=with_packages,
+        python_version=python_version,
+        with_requirements=with_requirements,
+        project=project,
+    )
 
     # Build server spec from parsed components
     if server_object:

src/fastmcp/cli/install/claude_desktop.py

@@ -9,6 +9,7 @@
 from rich import print
 
 from fastmcp.mcp_config import StdioMCPServer, update_config_file
+from fastmcp.utilities.cli import build_uv_run_args
 from fastmcp.utilities.logging import get_logger
 
 from .shared import process_common_args
@@ -72,31 +73,14 @@ def install_claude_desktop(
 
     config_file = config_dir / "claude_desktop_config.json"
 
-    # Build uv run command
-    args = ["run"]
-
-    # Add Python version if specified
-    if python_version:
-        args.extend(["--python", python_version])
-
-    # Add project if specified
-    if project:
-        args.extend(["--project", str(project)])
-
-    # Collect all packages in a set to deduplicate
-    packages = {"fastmcp"}
-    if with_packages:
-        packages.update(pkg for pkg in with_packages if pkg)
-
-    # Add all packages with --with
-    for pkg in sorted(packages):
-        args.extend(["--with", pkg])
-
-    if with_editable:
-        args.extend(["--with-editable", str(with_editable)])
-
-    if with_requirements:
-        args.extend(["--with-requirements", str(with_requirements)])
+    # Build uv run command using centralized function
+    args = build_uv_run_args(
+        with_editable=with_editable,
+        with_packages=with_packages,
+        python_version=python_version,
+        with_requirements=with_requirements,
+        project=project,
+    )
 
     # Build server spec from parsed components
     if server_object:

src/fastmcp/cli/install/cursor.py

@@ -10,6 +10,7 @@
 from rich import print
 
 from fastmcp.mcp_config import StdioMCPServer, update_config_file
+from fastmcp.utilities.cli import build_uv_run_args
 from fastmcp.utilities.logging import get_logger
 
 from .shared import process_common_args
@@ -106,31 +107,14 @@ def install_cursor_workspace(
 
     config_file = cursor_dir / "mcp.json"
 
-    # Build uv run command
-    args = ["run"]
-
-    # Add Python version if specified
-    if python_version:
-        args.extend(["--python", python_version])
-
-    # Add project if specified
-    if project:
-        args.extend(["--project", str(project)])
-
-    # Collect all packages in a set to deduplicate
-    packages = {"fastmcp"}
-    if with_packages:
-        packages.update(pkg for pkg in with_packages if pkg)
-
-    # Add all packages with --with
-    for pkg in sorted(packages):
-        args.extend(["--with", pkg])
-
-    if with_editable:
-        args.extend(["--with-editable", str(with_editable)])
-
-    if with_requirements:
-        args.extend(["--with-requirements", str(with_requirements)])
+    # Build uv run command using centralized function
+    args = build_uv_run_args(
+        with_editable=with_editable,
+        with_packages=with_packages,
+        python_version=python_version,
+        with_requirements=with_requirements,
+        project=project,
+    )
 
     # Build server spec from parsed components
     if server_object:
@@ -194,31 +178,14 @@ def install_cursor(
     Returns:
         True if installation was successful, False otherwise
     """
-    # Build uv run command
-    args = ["run"]
-
-    # Add Python version if specified
-    if python_version:
-        args.extend(["--python", python_version])
-
-    # Add project if specified
-    if project:
-        args.extend(["--project", str(project)])
-
-    # Collect all packages in a set to deduplicate
-    packages = {"fastmcp"}
-    if with_packages:
-        packages.update(pkg for pkg in with_packages if pkg)
-
-    # Add all packages with --with
-    for pkg in sorted(packages):
-        args.extend(["--with", pkg])
-
-    if with_editable:
-        args.extend(["--with-editable", str(with_editable)])
-
-    if with_requirements:
-        args.extend(["--with-requirements", str(with_requirements)])
+    # Build uv run command using centralized function
+    args = build_uv_run_args(
+        with_editable=with_editable,
+        with_packages=with_packages,
+        python_version=python_version,
+        with_requirements=with_requirements,
+        project=project,
+    )
 
     # Build server spec from parsed components
     if server_object:

src/fastmcp/cli/install/mcp_json.py

@@ -9,6 +9,7 @@
 import pyperclip
 from rich import print
 
+from fastmcp.utilities.cli import build_uv_run_args
 from fastmcp.utilities.logging import get_logger
 
 from .shared import process_common_args
@@ -47,31 +48,14 @@ def install_mcp_json(
         True if generation was successful, False otherwise
     """
     try:
-        # Build uv run command
-        args = ["run"]
-
-        # Add Python version if specified
-        if python_version:
-            args.extend(["--python", python_version])
-
-        # Add project if specified
-        if project:
-            args.extend(["--project", str(project)])
-
-        # Collect all packages in a set to deduplicate
-        packages = {"fastmcp"}
-        if with_packages:
-            packages.update(pkg for pkg in with_packages if pkg)
-
-        # Add all packages with --with
-        for pkg in sorted(packages):
-            args.extend(["--with", pkg])
-
-        if with_editable:
-            args.extend(["--with-editable", str(with_editable)])
-
-        if with_requirements:
-            args.extend(["--with-requirements", str(with_requirements)])
+        # Build uv run command using centralized function
+        args = build_uv_run_args(
+            with_editable=with_editable,
+            with_packages=with_packages,
+            python_version=python_version,
+            with_requirements=with_requirements,
+            project=project,
+        )
 
         # Build server spec from parsed components
         if server_object: