import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
import { applyFilters, outputFiltersSchema } from "./filters.js";
type SSHExecutor = (command: string) => Promise<string>;
const systemActions = ["list_files", "read_file", "find_files", "disk_usage", "system_info"] as const;
export function registerSystemTools(
server: McpServer,
sshExecutor: SSHExecutor
): void {
server.tool(
"system",
"System ops.",
{
action: z.enum(systemActions).describe("Action"),
path: z.string().optional().describe("Path"),
pattern: z.string().optional().describe("Pattern"),
long: z.boolean().optional().describe("Long format"),
maxLines: z.number().int().positive().optional().default(1000).describe("Max lines"),
...outputFiltersSchema.shape,
},
async (args) => {
try {
switch (args.action) {
case "list_files": {
if (!args.path) return { content: [{ type: "text", text: "Error: path required" }], isError: true };
let cmd = args.long ? `ls -lah "${args.path}"` : `ls "${args.path}"`;
cmd = applyFilters(cmd, args);
const output = await sshExecutor(cmd);
return { content: [{ type: "text", text: output }] };
}
case "read_file": {
if (!args.path) return { content: [{ type: "text", text: "Error: path required" }], isError: true };
const maxLines = args.maxLines ?? 1000;
let cmd = maxLines > 0 ? `head -n ${maxLines} "${args.path}"` : `cat "${args.path}"`;
cmd = applyFilters(cmd, args);
const output = await sshExecutor(cmd);
const lineCount = output.split("\n").length;
let result = output;
if (!args.grep && !args.tail && !args.head && lineCount >= maxLines) {
result += `\n\n[Limited to ${maxLines} lines]`;
}
return { content: [{ type: "text", text: result }] };
}
case "find_files": {
if (!args.path || !args.pattern) return { content: [{ type: "text", text: "Error: path and pattern required" }], isError: true };
let cmd = `find "${args.path}" -name "${args.pattern}" -type f 2>/dev/null`;
cmd = applyFilters(cmd, args);
const output = await sshExecutor(cmd);
if (!output?.trim()) return { content: [{ type: "text", text: `No files matching "${args.pattern}" in ${args.path}` }] };
const files = output.trim().split("\n");
let result = output;
if (files.length > 1000) {
result = files.slice(0, 1000).join("\n") + `\n\n[Found ${files.length}, showing 1000]`;
}
return { content: [{ type: "text", text: result }] };
}
case "disk_usage": {
const path = args.path ?? "/";
let cmd = applyFilters(`df -h "${path}"`, args);
const output = await sshExecutor(cmd);
return { content: [{ type: "text", text: output }] };
}
case "system_info": {
let cmd = applyFilters(`uname -a && echo "---" && uptime && echo "---" && free -h`, args);
const output = await sshExecutor(cmd);
return { content: [{ type: "text", text: output }] };
}
default:
return { content: [{ type: "text", text: `Unknown action: ${args.action}` }], isError: true };
}
} catch (error) {
return { content: [{ type: "text", text: `Error: ${error instanceof Error ? error.message : String(error)}` }], isError: true };
}
}
);
}
