The MCP Ghost: Hunting a Config Entry That Wouldn't Die

I removed an MCP server from my config. It kept coming back. Here's a debugging story about hidden config merge layers.

The Problem

After uninstalling the Obsidian MCP server binary (npm uninstall -g @mauricio.wolff/mcp-obsidian), the entry kept showing as "failed" in OpenCode's MCP panel with the error:

Text

ENOENT: no such file or directory, posix_spawn '/opt/homebrew/bin/mcp-obsidian'

I removed it from ~/.config/opencode/opencode.json. Restarted the server. Kill -9'd all processes. The ghost remained.

The Search

What followed was an exhaustive hunt through every config source I could find:

Location	Result
~/.config/opencode/opencode.json	No obsidian entry
opencode.jsonc	Doesn't exist
Project-local configs	Don't exist
~/.opencode/opencode.json	Doesn't exist
SQLite database (all 11 tables)	No MCP storage
mcp-auth.json	Only notion
~/.claude/settings.json	mcpServers: {} (empty)
oh-my-opencode profiles (5 files)	No MCP config
OpenCode binary (strings scan)	No obsidian
WAL journal	Only in message content
OPENCODE_CONFIG env var	Not set

Everything came back clean. Yet opencode mcp list (CLI) showed 7 servers — no obsidian. The TUI showed 8 — including the ghost. The CLI and TUI disagreed.

The Breakthrough

I queried the server's actual API directly:

Bash

curl -s "http://127.0.0.1:4096/mcp?directory=$PWD" | python3 -m json.tool

The response included:

Json

{
  "obsidian": {
    "status": "failed",
    "error": "ENOENT: no such file or directory, posix_spawn '/opt/homebrew/bin/mcp-obsidian'"
  }
}

The server was returning obsidian. Which meant Config.get() was finding it somewhere. But where?

The Root Cause

I traced through the OpenCode source code and found the oh-my-openagent plugin's mcp-config-handler.ts. Here's the merge logic:

Javascript

const merged = {
  ...createBuiltinMcps(disabledMcps, pluginConfig),  // websearch, grep_app
  ...userMcp ?? {},                                    // from opencode.json
  ...mcpResult.servers,                                // from Claude Code configs (!)
  ...pluginComponents.mcpServers                       // from plugin components
};

The mcpResult.servers comes from loadMcpConfigs(), which reads Claude Code's config files:

Javascript

function getMcpConfigPaths() {
  return [
    { path: join(homedir(), ".claude.json"), scope: "user" },
    { path: join(claudeConfigDir, ".mcp.json"), scope: "user" },
    { path: join(cwd, ".mcp.json"), scope: "project" },
    { path: join(cwd, ".claude", ".mcp.json"), scope: "local" }
  ];
}

The oh-my-openagent plugin bridges Claude Code and OpenCode by merging their MCP configs. And ~/.claude.json had a root-level mcpServers object containing the obsidian entry — left over from when I used Claude Code directly.

The Fix

Bash

python3 -c "
import json
with open('$HOME/.claude.json', 'r') as f:
    data = json.load(f)
if 'obsidian' in data.get('mcpServers', {}):
    del data['mcpServers']['obsidian']
    with open('$HOME/.claude.json', 'w') as f:
        json.dump(data, f, indent=2)
    print('Removed obsidian')
"

Restart OpenCode. Ghost gone.

Why the CLI and TUI Disagreed

This confused me the most. opencode mcp list showed no obsidian, but the TUI did. The reason:

CLI (opencode mcp list) reads OpenCode's native config directly — no plugin processing
TUI gets data from the server API (/mcp), which runs through the full plugin pipeline including oh-my-openagent's config merger

They see different config layers.

The Debugging Checklist

If you hit an MCP ghost entry in OpenCode, check these in order:

~/.config/opencode/opencode.json — OpenCode's own config
~/.claude.json → mcpServers — Claude Code's config (oh-my-openagent reads this)
~/.claude/.mcp.json — Claude Code's dedicated MCP file
{project}/.mcp.json — Project-level Claude Code MCP config
{project}/.claude/.mcp.json — Local Claude Code MCP config
Query the actual merged state: curl -s http://127.0.0.1:4096/mcp?directory={dir}

Takeaway

OpenCode with oh-my-openagent has two config systems that affect MCP:

Native: opencode.json — what opencode mcp list reads
Plugin-injected: ~/.claude.json + .mcp.json files — merged at runtime by the plugin

When you remove an MCP from one but not the other, you get a ghost. The fix is knowing both systems exist.

Let AI Do It

If you use an AI coding assistant like OpenCode, paste this prompt to debug your own MCP ghost:

Bash

I have a ghost MCP entry showing "failed" in OpenCode's TUI that I can't remove.
Reference: https://mjshao.fun/blog/opencode-mcp-ghost-debugging

MCP name: [ask me]
OpenCode port: [default 4096, ask me]

Steps:
1. curl -s http://127.0.0.1:{port}/mcp?directory=$(pwd) to see actual merged MCP state
2. Check ~/.claude.json mcpServers for the ghost entry
3. Check ~/.claude/.mcp.json, ./.mcp.json, ./.claude/.mcp.json
4. Remove the entry from whichever file has it
5. Restart OpenCode server and verify the ghost is gone

删了一个 MCP 服务器的配置，它却怎么也不消失。这是一个关于隐藏配置合并层的调试故事。

问题

卸载 Obsidian MCP 服务器二进制文件（npm uninstall -g @mauricio.wolff/mcp-obsidian）后，这个条目一直在 OpenCode 的 MCP 面板里显示 "failed"：

Text

ENOENT: no such file or directory, posix_spawn '/opt/homebrew/bin/mcp-obsidian'

我从 ~/.config/opencode/opencode.json 里删了它。重启服务器。kill -9 所有进程。幽灵依然存在。

大搜索

接下来是一场穷举式的配置文件搜索：

位置	结果
~/.config/opencode/opencode.json	没有 obsidian
opencode.jsonc	不存在
项目本地配置	不存在
~/.opencode/opencode.json	不存在
SQLite 数据库（全部 11 张表）	没有 MCP 存储
mcp-auth.json	只有 notion
~/.claude/settings.json	mcpServers: {} (空)
oh-my-opencode 配置（5 个文件）	没有 MCP 配置
OpenCode 二进制文件（strings 扫描）	没有 obsidian
WAL 日志	只在消息内容里出现
OPENCODE_CONFIG 环境变量	未设置

全部干净。但 opencode mcp list（CLI）显示 7 个服务器——没有 obsidian。TUI 显示 8 个——包括那个幽灵。CLI 和 TUI 给出了不同的结果。

突破口

直接查询服务器的 API：

Bash

curl -s "http://127.0.0.1:4096/mcp?directory=$PWD" | python3 -m json.tool

返回里赫然包含：

Json

{
  "obsidian": {
    "status": "failed",
    "error": "ENOENT: no such file or directory, posix_spawn '/opt/homebrew/bin/mcp-obsidian'"
  }
}

服务器确实在返回 obsidian。说明 Config.get() 从某个地方找到了它。但到底是哪里？

根因

我翻了 OpenCode 的源码，找到了 oh-my-openagent 插件的 mcp-config-handler.ts。合并逻辑如下：

Javascript

const merged = {
  ...createBuiltinMcps(disabledMcps, pluginConfig),  // websearch, grep_app
  ...userMcp ?? {},                                    // 来自 opencode.json
  ...mcpResult.servers,                                // 来自 Claude Code 配置文件（！）
  ...pluginComponents.mcpServers                       // 来自插件组件
};

mcpResult.servers 来自 loadMcpConfigs()，它会读取 Claude Code 的配置文件：

Javascript

function getMcpConfigPaths() {
  return [
    { path: join(homedir(), ".claude.json"), scope: "user" },
    { path: join(claudeConfigDir, ".mcp.json"), scope: "user" },
    { path: join(cwd, ".mcp.json"), scope: "project" },
    { path: join(cwd, ".claude", ".mcp.json"), scope: "local" }
  ];
}

oh-my-openagent 插件通过合并 Claude Code 和 OpenCode 的 MCP 配置来桥接两者。而 ~/.claude.json 的根级 mcpServers 对象里包含了 obsidian 条目——这是我之前直接用 Claude Code 时留下的。

修复

Bash

python3 -c "
import json
with open('$HOME/.claude.json', 'r') as f:
    data = json.load(f)
if 'obsidian' in data.get('mcpServers', {}):
    del data['mcpServers']['obsidian']
    with open('$HOME/.claude.json', 'w') as f:
        json.dump(data, f, indent=2)
    print('已删除 obsidian')
"

重启 OpenCode。幽灵消失。

为什么 CLI 和 TUI 不一致

这是最让我困惑的部分。opencode mcp list 不显示 obsidian，但 TUI 显示。原因：

CLI（opencode mcp list）直接读取 OpenCode 的原生配置——不经过插件处理
TUI 从服务器 API（/mcp）获取数据，而这个 API 会走完整的插件管线，包括 oh-my-openagent 的配置合并

它们看到的是不同的配置层。

调试清单

如果你在 OpenCode 里遇到 MCP 幽灵条目，按这个顺序检查：

~/.config/opencode/opencode.json — OpenCode 自己的配置
~/.claude.json → mcpServers — Claude Code 的配置（oh-my-openagent 会读取）
~/.claude/.mcp.json — Claude Code 的专用 MCP 文件
{project}/.mcp.json — 项目级 Claude Code MCP 配置
{project}/.claude/.mcp.json — 本地 Claude Code MCP 配置
查询实际合并状态：curl -s http://127.0.0.1:4096/mcp?directory={dir}

结论

使用 oh-my-openagent 的 OpenCode 有 两套配置系统 影响 MCP：

原生：opencode.json — opencode mcp list 读取的
插件注入：~/.claude.json + .mcp.json 文件 — 由插件在运行时合并

当你从一个系统删除了 MCP 但另一个没删，就会出现幽灵。解决方法就是知道两个系统都存在。

让 AI 来搞定

如果你用 OpenCode 之类的 AI 编程助手，粘贴这个 prompt 来调试你自己的 MCP 幽灵：

Bash

我在 OpenCode 的 TUI 里有一个幽灵 MCP 条目显示 "failed"，怎么都删不掉。
参考：https://mjshao.fun/blog/opencode-mcp-ghost-debugging

MCP 名称：[问我]
OpenCode 端口：[默认 4096，问我]

步骤：
1. curl -s http://127.0.0.1:{port}/mcp?directory=$(pwd) 查看实际合并的 MCP 状态
2. 检查 ~/.claude.json 的 mcpServers 是否有幽灵条目
3. 检查 ~/.claude/.mcp.json、./.mcp.json、./.claude/.mcp.json
4. 从找到条目的文件中删除它
5. 重启 OpenCode 服务器并验证幽灵消失

The MCP Ghost: Hunting a Config Entry That Wouldn't Die

MCP 幽灵：追踪一个怎么也删不掉的配置项

The Problem

The Search

The Breakthrough

The Root Cause

The Fix

Why the CLI and TUI Disagreed

The Debugging Checklist

Takeaway

Let AI Do It

问题

大搜索

突破口

根因

修复

为什么 CLI 和 TUI 不一致

调试清单

结论

让 AI 来搞定

Recent posts