ai-mcp：给大模型操作的 MCP 开关 server 插件

- 注册 mcp_switch 工具（action = on / off / status），供大模型自主切换 MCP 状态 - 与 TUI 插件共用同一份 mcpcfg.txt、同一套对调与校验逻辑，状态判定只看活文件是否含 mcp.servers - 模式门控：自动=允许切换；手动=拒绝并提示用户用 /mcpon /mcpoff；关闭=一律拒绝（status 始终可查） - 切换 = 对调两份配置 + 校验 + reload 热重载（SDK location.reload 三连尝试，失败回落 POST /api/location/reload） - 双导出：命名导出 AiMcp（文档形式）与 default { id, setup }（v2 校验形式），保证任一加载器都能注册成功 - tool helper 走动态 import + 降级日志，WSL 端缺 node_modules 时不会让整个插件加载失败 - 日志优先 client.app.log，失败回落 ~/.config/opencode/ai-mcp.log
2026-09-23 12:06:31 +08:00
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+# 构建/依赖产物
+node_modules/
+*.tsbuildinfo
+
+# 编辑器与系统
+.vscode/
+.idea/
+.DS_Store
+Thumbs.db
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+// ai-mcp —— 给大模型操作的 MCP 开关 server 插件
+//
+// 职责：通过 mcp_switch 工具，让大模型自己切换「配置对调」状态，
+//       实现 MCP 的热开/热关（对调 opencode.json 两份配置 + reload 重载）。
+//
+// 模式（mcpcfg.txt 第1行）语义：
+//   - 自动 auto ：大模型可自由调用本工具切换状态；/mcpon /mcpoff 视为手动切换一次
+//   - 手动 manual：只允许用户用 /mcpon /mcpoff，本工具拒绝切换（status 仍可查）
+//   - 关闭 off  ：功能整体禁用，本工具拒绝一切操作
+//
+// 与 TUI 插件 oc-session-all 共用同一份 mcpcfg.txt、同一套对调/校验/reload 逻辑。
+
+import type { Plugin } from "@opencode-ai/plugin"
+import { appendFileSync, existsSync, mkdirSync, readFileSync, writeFileSync } from "node:fs"
+import { homedir } from "node:os"
+import { basename, join } from "node:path"
+
+const LOG_DIR = join(homedir(), ".config", "opencode")
+const CFG_TXT = join(LOG_DIR, "mcpcfg.txt")
+const LOG_FILE = join(LOG_DIR, "ai-mcp.log")
+const MODE_LABEL: Record<string, string> = { auto: "自动", manual: "手动", off: "关闭" }
+
+// ---------------------------------------------------------------- 本地日志兜底
+function fileLog(msg: string) {
+  try {
+    if (!existsSync(LOG_DIR)) mkdirSync(LOG_DIR, { recursive: true })
+    appendFileSync(LOG_FILE, `[${new Date().toISOString()}] ${msg}\n`)
+  } catch {
+    // 日志失败绝不影响主流程
+  }
+}
+
+// 优先走 client.app.log（结构化），失败回落本地文件
+async function slog(client: any, level: string, message: string, extra?: any) {
+  try {
+    if (client && typeof client.app?.log === "function") {
+      await client.app.log({ body: { service: "ai-mcp", level, message, extra } })
+      return
+    }
+  } catch {
+    // 落到下面的文件日志
+  }
+  fileLog(`${level.toUpperCase()} ${message}${extra ? " " + JSON.stringify(extra) : ""}`)
+}
+
+// ---------------------------------------------------------------- mcpcfg 解析
+// 与 tui.js 的 readMcpCfg 保持逐字一致，避免两端行为分叉
+function readMcpCfg() {
+  try {
+    if (!existsSync(CFG_TXT)) {
+      return { mode: "off", missing: true, error: "缺少 mcpcfg.txt（配置缺失，功能视为关闭）" } as any
+    }
+    const lines = readFileSync(CFG_TXT, "utf8").split(/\r?\n/)
+    const key = (lines[0] || "").trim().toLowerCase()
+    let mode: string
+    if (["auto", "audo", "自动"].includes(key) || key === "") mode = "auto"
+    else if (["manual", "hand", "on", "手动"].includes(key)) mode = "manual"
+    else if (["off", "disable", "disabled", "关闭"].includes(key)) mode = "off"
+    else mode = "auto"
+
+    const onPath = (lines[1] || "").trim()
+    const quietPath = (lines[2] || "").trim()
+
+    // 活文件 = 两行中文件名为 opencode.json 的那份（OC 只读这个名字）
+    let activePath: string | null = null
+    let shadowPath: string | null = null
+    if (basename(onPath) === "opencode.json") {
+      activePath = onPath
+      shadowPath = quietPath
+    } else if (basename(quietPath) === "opencode.json") {
+      activePath = quietPath
+      shadowPath = onPath
+    }
+
+    const result: any = { mode, onPath, quietPath, activePath, shadowPath, missing: false, error: null }
+    if (mode !== "off" && !activePath) {
+      result.error = "mcpcfg.txt 第2/3行必须有一个是 opencode.json 的完整路径"
+    } else if (mode !== "off" && (!existsSync(onPath) || !existsSync(quietPath))) {
+      result.error = "mcpcfg.txt 第2/3行指向的文件不存在（请检查路径）"
+    }
+    return result
+  } catch (e: any) {
+    return { mode: "off", error: "读取 mcpcfg.txt 失败: " + e.message } as any
+  }
+}
+
+// 状态判定只看活文件是否含 mcp，与 txt 行语义无关（对调后身份漂移无影响）
+function activeHasMcp(activePath: string | null) {
+  try {
+    if (!activePath) return false
+    const j = JSON.parse(readFileSync(activePath, "utf8"))
+    return !!(j.mcp && j.mcp.servers && Object.keys(j.mcp.servers).length > 0)
+  } catch {
+    return false
+  }
+}
+
+// 交换两文件内容（对调）
+function swapFiles(a: string, b: string) {
+  const ca = readFileSync(a, "utf8")
+  const cb = readFileSync(b, "utf8")
+  writeFileSync(a, cb)
+  writeFileSync(b, ca)
+}
+
+// ---------------------------------------------------------------- reload 热重载
+// 链路：client.location.reload({location}) → ({}) → 无参 → HTTP POST /api/location/reload
+async function doReload(client: any, serverUrl: any) {
+  const attempts: Array<() => Promise<any>> = []
+  if (client && client.location && typeof client.location.reload === "function") {
+    attempts.push(() => client.location.reload({ location: undefined as any }))
+    attempts.push(() => client.location.reload({}))
+    attempts.push(() => client.location.reload())
+  }
+  if (serverUrl) {
+    attempts.push(async () => {
+      const res = await fetch(new URL("/api/location/reload", serverUrl), {
+        method: "POST",
+        headers: { "content-type": "application/json" },
+        body: "{}",
+      })
+      if (!res.ok) throw new Error(`HTTP ${res.status}`)
+      return res
+    })
+  }
+
+  let lastErr: any = null
+  for (const fn of attempts) {
+    try {
+      await fn()
+      await slog(client, "info", "location.reload 成功（MCP 已热重载）")
+      return { ok: true, how: "reload" }
+    } catch (e: any) {
+      lastErr = e
+    }
+  }
+  const msg = lastErr ? lastErr.message : "没有可用的 reload 通道"
+  await slog(client, "warn", "location.reload 失败: " + msg)
+  return { ok: false, why: msg }
+}
+
+// ---------------------------------------------------------------- 切换主逻辑
+type SetResult = { ok: boolean; unchanged?: boolean; reloaded?: boolean; why?: string | null; state?: string }
+
+async function setMcp(ctx: any, wantOn: boolean): Promise<SetResult> {
+  const cfg = readMcpCfg()
+  if (cfg.error) return { ok: false, why: cfg.error }
+  if (cfg.mode === "off") return { ok: false, why: "MCP 开关功能已被关闭（mcpcfg.txt 第1行=关闭）" }
+
+  const cur = activeHasMcp(cfg.activePath)
+  if (cur === wantOn) {
+    return {
+      ok: true,
+      unchanged: true,
+      state: wantOn ? "开启" : "关闭",
+      why: wantOn ? "MCP 已是开启状态" : "MCP 已是关闭（安静）状态",
+    }
+  }
+
+  swapFiles(cfg.onPath, cfg.quietPath)
+
+  const now = activeHasMcp(cfg.activePath)
+  if (now !== wantOn) {
+    await slog(ctx?.client, "error", `配置对调后状态校验失败 want=${wantOn} got=${now}`)
+    return { ok: false, why: "配置对调后状态校验失败（请检查 mcpcfg.txt 第2/3行路径）" }
+  }
+
+  await slog(ctx?.client, "info", `配置已对调 -> ${wantOn ? "含 MCP" : "安静（无 MCP）"}`)
+  const r = await doReload(ctx?.client, ctx?.serverUrl)
+  return {
+    ok: true,
+    reloaded: r.ok,
+    state: wantOn ? "开启" : "关闭",
+    why: r.ok ? null : "配置已对调，但热重载调用失败（重启 OC 生效）：" + (r.why || ""),
+  }
+}
+
+// ---------------------------------------------------------------- tool helper 装载
+// 动态 import：WSL 端 plugins/ 可能没有 node_modules，绝不能让整文件加载崩掉
+let toolHelper: any = null
+let toolHelperErr: string | null = null
+
+async function loadToolHelper(): Promise<any> {
+  if (toolHelper) return toolHelper
+  try {
+    const mod: any = await import("@opencode-ai/plugin")
+    if (mod && typeof mod.tool === "function") {
+      toolHelper = mod.tool
+      return toolHelper
+    }
+    toolHelperErr = "@opencode-ai/plugin 未导出 tool 方法"
+  } catch (e: any) {
+    toolHelperErr = e && e.message ? e.message : String(e)
+  }
+  return null
+}
+
+function modeLabel(m: string) {
+  return MODE_LABEL[m] || m
+}
+
+// ---------------------------------------------------------------- 工具本体
+async function buildHooks(ctx: any) {
+  const toolFn = await loadToolHelper()
+  if (!toolFn) {
+    await slog(
+      ctx?.client,
+      "error",
+      "无法加载 @opencode-ai/plugin，mcp_switch 工具未注册。请在 plugins/ 目录执行依赖安装（bun install / npm install）。原因：" +
+        toolHelperErr,
+    )
+    return {}
+  }
+
+  return {
+    tool: {
+      mcp_switch: toolFn({
+        description:
+          "切换 OpenCode 的 MCP 开关状态（配置对调 + 热重载）。" +
+          "action=on 把配置对调为含 MCP 的原始版并重载，让 MCP 连接问题暴露出来便于排查；" +
+          "action=off 对调为不含 MCP 的安静版并重载，恢复零提示的安静状态；" +
+          "action=status 只查询当前模式与 MCP 状态，不改动任何文件。" +
+          "仅在 mcpcfg.txt 第1行为「自动」时允许切换；「手动」模式请让用户执行 /mcpon 或 /mcpoff；「关闭」模式直接拒绝。",
+        args: {
+          action: toolFn.schema.enum(["on", "off", "status"]),
+        },
+        async execute(args: any, _context: any) {
+          const action = String(args?.action || "status")
+          const cfg = readMcpCfg()
+
+          if (cfg.error) {
+            return { title: "MCP 开关失败", output: "失败：" + cfg.error }
+          }
+
+          const hasMcp = activeHasMcp(cfg.activePath)
+          const modeTxt = modeLabel(cfg.mode)
+
+          if (action === "status") {
+            return {
+              title: "MCP 当前状态",
+              output: [
+                `模式：${modeTxt}（mcpcfg.txt 第1行）`,
+                `MCP：${hasMcp ? "已开启（配置含 mcp.servers）" : "已关闭（安静，无 mcp 配置）"}`,
+                `活配置文件：${cfg.activePath}`,
+                `对调目标文件：${cfg.onPath === cfg.activePath ? cfg.quietPath : cfg.onPath}`,
+                cfg.mode === "manual" ? "提示：手动模式下只能由用户执行 /mcpon 或 /mcpoff。" : "",
+              ]
+                .filter(Boolean)
+                .join("\n"),
+            }
+          }
+
+          if (cfg.mode === "off") {
+            return {
+              title: "MCP 开关被禁用",
+              output: "拒绝执行：MCP 开关功能已关闭（mcpcfg.txt 第1行=关闭）。如需使用，请让用户把第1行改成「自动」。",
+            }
+          }
+
+          if (cfg.mode === "manual") {
+            return {
+              title: "手动模式拒绝",
+              output:
+                "拒绝执行：当前是手动模式，只有用户能切换 MCP 状态。\n" +
+                "请提醒用户在输入框执行 /mcpon（开启）或 /mcpoff（关闭）；" +
+                "如果确实需要大模型自动切换，让用户把 mcpcfg.txt 第1行改成「自动」。",
+            }
+          }
+
+          // auto 模式：执行切换
+          const wantOn = action === "on"
+          await slog(ctx?.client, "info", `mcp_switch 收到 action=${action}（自动模式）`)
+          const res = await setMcp(ctx, wantOn)
+
+          if (!res.ok) {
+            await slog(ctx?.client, "error", "mcp_switch 失败: " + res.why)
+            return { title: "MCP 切换失败", output: "失败：" + res.why }
+          }
+          if (res.unchanged) {
+            return { title: "MCP 状态未变", output: "无需切换。" + res.why }
+          }
+          const reloadTxt = res.reloaded
+            ? "配置已对调并完成热重载，MCP 配置立即生效。"
+            : "配置已对调，但热重载未成功：" + (res.why || "") + "\n需要重启 OpenCode 才能生效。"
+          return {
+            title: "MCP 已切换",
+            output: `已把 MCP 切换为「${res.state}」状态。\n${reloadTxt}`,
+          }
+        },
+      }),
+    },
+  }
+}
+
+// ---------------------------------------------------------------- 双导出
+// 1) 命名导出：官方文档形式（export const X: Plugin = async (ctx) => ...）
+export const AiMcp: Plugin = async (ctx) => {
+  await slog(ctx?.client, "info", "ai-mcp server 插件已加载（命名导出）")
+  return await buildHooks(ctx)
+}
+
+// 2) default 导出：v2 校验形式（{ id, setup }），与命名导出返回同一套 hooks，
+//    无论加载器认哪一种，mcp_switch 都能注册成功（同名工具后者覆盖，行为一致）。
+export default {
+  id: "ai-mcp",
+  async setup(ctx: any) {
+    await slog(ctx?.client, "info", "ai-mcp server 插件已加载（default/setup）")
+    return await buildHooks(ctx)
+  },
+}