MCP does not respond in CC terminal #39
Description
Is this a support request?
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Describe the bug
I've connected the LD MCP by pasting the following snippet in my .claude.json
"LaunchDarkly": {
"command": "npx",
"args": [
"-y",
"--package",
"@launchdarkly/mcp-server",
"--",
"mcp",
"start",
"--api-key",
"api-key-xxxx"
]
},
I am on an enterprise API billing plan so we run CC on the terminal (or via the VSC extension). The connection to the MCP server seems to be successful.
The issue happens when I attempt to use the MCP in any way. Here I am just trying a test prompt and it immediately responds with what seems to be the correct next step. However, no matter how long I wait, I never get a response.
Note that I have tried installing the LD MCP via all the other ways available (I think). I've tried adding it myself in claude with --mcp mcp.json. I also tried installing the project locally but I wasn't able to get that to work.
I am not sure whether I am missing any debugging steps; I haven't been able to find a more verbose response with claude to see what is it doing. The only log I was able to get my hands on was the one in /Users/odymas/Library/Caches/claude-cli-nodejs/-Users-odymas-path-to-dir-dir/mcp-logs-LaunchDarkly/2026-01-16T14-57-36-660Z.jsonl
{"debug":"Starting connection with timeout of 30000ms","timestamp":"2026-01-16T14:57:36.745Z","sessionId":"d81e7ca0-55f0-423c-9dc1-656e072c15fd","cwd":"/Users/odymas/path-to-dir/dir"}
{"debug":"Successfully connected to undefined server in 2605ms","timestamp":"2026-01-16T14:57:39.350Z","sessionId":"d81e7ca0-55f0-423c-9dc1-656e072c15fd","cwd":"/Users/odymas/path-to-dir/dir"}
{"debug":"Connection established with capabilities: {\"hasTools\":true,\"hasPrompts\":false,\"hasResources\":false,\"serverVersion\":{\"name\":\"LaunchDarkly\",\"version\":\"0.4.2\"}}","timestamp":"2026-01-16T14:57:39.350Z","sessionId":"d81e7ca0-55f0-423c-9dc1-656e072c15fd","cwd":"/Users/odymas/path-to-dir/dir"}
To reproduce
Basically any way I try to use the MCP tool while on an API usage billing plan.
Expected behavior
Expected the MCP to report back with the right data.
Logs
Added it above.
Package version
The latest version I believe.
Language version, developer tools
Node: v20.16.0
Claude: v2.1.9
OS/platform
macOS 15.7.2.
Additional context
I am wondering whether CC terminal isn't supported... I thought I'd ask regardless. Thanks in advance.