icon to view:
37 | * Connected servers
38 | * Available prompts and resources
39 |
40 | 2. Click the 
icon to view:
41 | * Tools made available to the model
42 |
43 | ### Viewing logs
44 |
45 | Review detailed MCP logs from Claude Desktop:
46 |
47 | ```bash
48 | # Follow logs in real-time
49 | tail -n 20 -F ~/Library/Logs/Claude/mcp*.log
50 | ```
51 |
52 | The logs capture:
53 |
54 | * Server connection events
55 | * Configuration issues
56 | * Runtime errors
57 | * Message exchanges
58 |
59 | ### Using Chrome DevTools
60 |
61 | Access Chrome's developer tools inside Claude Desktop to investigate client-side errors:
62 |
63 | 1. Create a `developer_settings.json` file with `allowDevTools` set to true:
64 |
65 | ```bash
66 | echo '{"allowDevTools": true}' > ~/Library/Application\ Support/Claude/developer_settings.json
67 | ```
68 |
69 | 2. Open DevTools: `Command-Option-Shift-i`
70 |
71 | Note: You'll see two DevTools windows:
72 |
73 | * Main content window
74 | * App title bar window
75 |
76 | Use the Console panel to inspect client-side errors.
77 |
78 | Use the Network panel to inspect:
79 |
80 | * Message payloads
81 | * Connection timing
82 |
83 | ## Common issues
84 |
85 | ### Working directory
86 |
87 | When using MCP servers with Claude Desktop:
88 |
89 | * The working directory for servers launched via `claude_desktop_config.json` may be undefined (like `/` on macOS) since Claude Desktop could be started from anywhere
90 | * Always use absolute paths in your configuration and `.env` files to ensure reliable operation
91 | * For testing servers directly via command line, the working directory will be where you run the command
92 |
93 | For example in `claude_desktop_config.json`, use:
94 |
95 | ```json
96 | {
97 | "command": "npx",
98 | "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/username/data"]
99 | }
100 | ```
101 |
102 | Instead of relative paths like `./data`
103 |
104 | ### Environment variables
105 |
106 | MCP servers inherit only a subset of environment variables automatically, like `USER`, `HOME`, and `PATH`.
107 |
108 | To override the default variables or provide your own, you can specify an `env` key in `claude_desktop_config.json`:
109 |
110 | ```json
111 | {
112 | "myserver": {
113 | "command": "mcp-server-myapp",
114 | "env": {
115 | "MYAPP_API_KEY": "some_key",
116 | }
117 | }
118 | }
119 | ```
120 |
121 | ### Server initialization
122 |
123 | Common initialization problems:
124 |
125 | 1. **Path Issues**
126 | * Incorrect server executable path
127 | * Missing required files
128 | * Permission problems
129 | * Try using an absolute path for `command`
130 |
131 | 2. **Configuration Errors**
132 | * Invalid JSON syntax
133 | * Missing required fields
134 | * Type mismatches
135 |
136 | 3. **Environment Problems**
137 | * Missing environment variables
138 | * Incorrect variable values
139 | * Permission restrictions
140 |
141 | ### Connection problems
142 |
143 | When servers fail to connect:
144 |
145 | 1. Check Claude Desktop logs
146 | 2. Verify server process is running
147 | 3. Test standalone with [Inspector](/docs/tools/inspector)
148 | 4. Verify protocol compatibility
149 |
150 | ## Implementing logging
151 |
152 | ### Server-side logging
153 |
154 | When building a server that uses the local stdio [transport](/docs/concepts/transports), all messages logged to stderr (standard error) will be captured by the host application (e.g., Claude Desktop) automatically.
155 |
156 | 
73 |
74 |
75 | The Inspector provides several features for interacting with your MCP server:
76 |
77 | ### Server connection pane
78 |
79 | * Allows selecting the [transport](/docs/concepts/transports) for connecting to the server
80 | * For local servers, supports customizing the command-line arguments and environment
81 |
82 | ### Resources tab
83 |
84 | * Lists all available resources
85 | * Shows resource metadata (MIME types, descriptions)
86 | * Allows resource content inspection
87 | * Supports subscription testing
88 |
89 | ### Prompts tab
90 |
91 | * Displays available prompt templates
92 | * Shows prompt arguments and descriptions
93 | * Enables prompt testing with custom arguments
94 | * Previews generated messages
95 |
96 | ### Tools tab
97 |
98 | * Lists available tools
99 | * Shows tool schemas and descriptions
100 | * Enables tool testing with custom inputs
101 | * Displays tool execution results
102 |
103 | ### Notifications pane
104 |
105 | * Presents all logs recorded from the server
106 | * Shows notifications received from the server
107 |
108 | ## Best practices
109 |
110 | ### Development workflow
111 |
112 | 1. Start Development
113 | * Launch Inspector with your server
114 | * Verify basic connectivity
115 | * Check capability negotiation
116 |
117 | 2. Iterative testing
118 | * Make server changes
119 | * Rebuild the server
120 | * Reconnect the Inspector
121 | * Test affected features
122 | * Monitor messages
123 |
124 | 3. Test edge cases
125 | * Invalid inputs
126 | * Missing prompt arguments
127 | * Concurrent operations
128 | * Verify error handling and error responses
129 |
130 | ## Next steps
131 |
132 | 
9 |
10 |
11 | Don't worry — it will ask you for your permission before executing these actions!
12 |
13 | ## 1. Download Claude for Desktop
14 |
15 | Start by downloading [Claude for Desktop](https://claude.ai/download), choosing either macOS or Windows. (Linux is not yet supported for Claude for Desktop.)
16 |
17 | Follow the installation instructions.
18 |
19 | If you already have Claude for Desktop, make sure it's on the latest version by clicking on the Claude menu on your computer and selecting "Check for Updates..."
20 |
21 | 
35 |
36 |
37 | Click on "Developer" in the lefthand bar of the Settings pane, and then click on "Edit Config":
38 |
39 |
40 | 
41 |
42 |
43 | This will create a configuration file at:
44 |
45 | * macOS: `~/Library/Application Support/Claude/claude_desktop_config.json`
46 | * Windows: `%APPDATA%\Claude\claude_desktop_config.json`
47 |
48 | if you don't already have one, and will display the file in your file system.
49 |
50 | Open up the configuration file in any text editor. Replace the file contents with this:
51 |
52 | icon in the bottom right corner of the input box:
122 |
123 |
124 | 
125 |
126 |
127 | After clicking on the hammer icon, you should see the tools that come with the Filesystem MCP Server:
128 |
129 |
130 | 
131 |
132 |
133 | If your server isn't being picked up by Claude for Desktop, proceed to the [Troubleshooting](#troubleshooting) section for debugging tips.
134 |
135 | ## 4. Try it out!
136 |
137 | You can now talk to Claude and ask it about your filesystem. It should know when to call the relevant tools.
138 |
139 | Things you might try asking Claude:
140 |
141 | * Can you write a poem and save it to my desktop?
142 | * What are some work-related files in my downloads folder?
143 | * Can you take all the images on my desktop and move them to a new folder called "Images"?
144 |
145 | As needed, Claude will call the relevant tools and seek your approval before taking an action:
146 |
147 |
148 | 
149 |
150 |
151 | ## Troubleshooting
152 |
153 | -
109 |
- Bidirectional communication through stdin/stdout 110 |
- Process-based integration support 111 |
- Simple setup and configuration 112 |
- Lightweight implementation 113 |
Creates WebFlux-based SSE server transport.
Requires the mcp-spring-webflux dependency.
Implements the MCP HTTP with SSE transport specification, providing:
137 | 138 |-
139 |
- Reactive HTTP streaming with WebFlux 140 |
- Concurrent client connections through SSE endpoints 141 |
- Message routing and session management 142 |
- Graceful shutdown capabilities 143 |
Creates WebMvc-based SSE server transport.
Requires the mcp-spring-webmvc dependency.
Implements the MCP HTTP with SSE transport specification, providing:
168 | 169 |-
170 |
- Server-side event streaming 171 |
- Integration with Spring WebMVC 172 |
- Support for traditional web applications 173 |
- Synchronous operation handling 174 |
181 | Creates a Servlet-based SSE server transport. It is included in the core mcp module.
182 | The HttpServletSseServerTransport can be used with any Servlet container.
183 | To use it with a Spring Web application, you can register it as a Servlet bean:
184 |
204 | Implements the MCP HTTP with SSE transport specification using the traditional Servlet API, providing: 205 |
206 | 207 |-
208 |
- Asynchronous message handling using Servlet 6.0 async support 209 |
- Session management for multiple client connections 210 | 211 |
-
212 | Two types of endpoints:
213 |
214 |
-
215 |
- SSE endpoint (
/sse) for server-to-client events
216 | - Message endpoint (configurable) for client-to-server requests 217 |
219 |
220 | - SSE endpoint (
- Error handling and response formatting 221 |
- Graceful shutdown support 222 |