feat(lsp): add restartServer operation

packages/opencode/src/lsp/index.ts

@@ -466,6 +466,30 @@ export namespace LSP {
     return Promise.all(tasks)
   }
 
+  export async function restartByExtension(extension: string) {
+    const s = await state()
+    const restarted: string[] = []
+
+    for (const server of Object.values(s.servers)) {
+      if (server.extensions.length && !server.extensions.includes(extension)) continue
+
+      for (const client of s.clients.filter((c) => c.serverID === server.id)) {
+        log.info("restarting LSP server", { serverID: client.serverID, root: client.root })
+        await client.shutdown()
+        const idx = s.clients.indexOf(client)
+        if (idx >= 0) s.clients.splice(idx, 1)
+        s.broken.delete(client.root + client.serverID)
+        restarted.push(server.id)
+      }
+    }
+
+    if (restarted.length > 0) {
+      Bus.publish(Event.Updated, {})
+    }
+
+    return restarted
+  }
+
   export namespace Diagnostic {
     export function pretty(diagnostic: LSPClient.Diagnostic) {
       const severityMap = {

packages/opencode/src/tool/lsp.ts

@@ -16,17 +16,59 @@ const operations = [
   "prepareCallHierarchy",
   "incomingCalls",
   "outgoingCalls",
+  "restartServer",
 ] as const
 
 export const LspTool = Tool.define("lsp", {
   description: DESCRIPTION,
   parameters: z.object({
     operation: z.enum(operations).describe("The LSP operation to perform"),
-    filePath: z.string().describe("The absolute or relative path to the file"),
-    line: z.number().int().min(1).describe("The line number (1-based, as shown in editors)"),
-    character: z.number().int().min(1).describe("The character offset (1-based, as shown in editors)"),
+    filePath: z
+      .string()
+      .optional()
+      .describe("The absolute or relative path to the file (required for most operations)"),
+    line: z
+      .number()
+      .int()
+      .min(1)
+      .optional()
+      .describe("The line number (1-based, required for position-based operations)"),
+    character: z
+      .number()
+      .int()
+      .min(1)
+      .optional()
+      .describe("The character offset (1-based, required for position-based operations)"),
+    extension: z.string().optional().describe("File extension for restartServer operation (e.g., '.py', '.ts')"),
   }),
   execute: async (args) => {
+    if (args.operation === "restartServer") {
+      if (!args.extension) {
+        throw new Error("extension is required for restartServer operation")
+      }
+      const ext = args.extension.startsWith(".") ? args.extension : `.${args.extension}`
+      const restarted = await LSP.restartByExtension(ext)
+      const output =
+        restarted.length === 0
+          ? `No LSP servers found for extension ${ext}`
+          : `Restarted LSP server(s): ${restarted.join(", ")}`
+      return {
+        title: `restartServer ${ext}`,
+        metadata: { result: restarted },
+        output,
+      }
+    }
+
+    if (!args.filePath) {
+      throw new Error("filePath is required for this operation")
+    }
+    if (args.line === undefined) {
+      throw new Error("line is required for this operation")
+    }
+    if (args.character === undefined) {
+      throw new Error("character is required for this operation")
+    }
+
     const file = path.isAbsolute(args.filePath) ? args.filePath : path.join(Instance.directory, args.filePath)
     const uri = pathToFileURL(file).href
     const position = {
@@ -70,6 +112,8 @@ export const LspTool = Tool.define("lsp", {
           return LSP.incomingCalls(position)
         case "outgoingCalls":
           return LSP.outgoingCalls(position)
+        case "restartServer":
+          throw new Error("Unreachable")
       }
     })()
 

packages/opencode/src/tool/lsp.txt

@@ -10,10 +10,14 @@ Supported operations:
 - prepareCallHierarchy: Get call hierarchy item at a position (functions/methods)
 - incomingCalls: Find all functions/methods that call the function at a position
 - outgoingCalls: Find all functions/methods called by the function at a position
+- restartServer: Restart LSP server(s) for a file extension (useful after installing dependencies)
 
 All operations require:
 - filePath: The file to operate on
 - line: The line number (1-based, as shown in editors)
 - character: The character offset (1-based, as shown in editors)
 
+The restartServer operation requires:
+- extension: The file extension (e.g., ".py", ".ts")
+
 Note: LSP servers must be configured for the file type. If no server is available, an error will be returned.