Filesystem MCP Server

import { exec } from 'child_process'; import { promisify } from 'util'; import { z } from 'zod'; import { zodToJsonSchema } from 'zod-to-json-schema'; import { logger } from '../logger.js'; import { validatePath } from '../lib.js'; import type { ToolInput, MCPResponse, HandlerFunction } from './types.js'; const execAsync = promisify(exec); const GitArgsSchema = z.object({ command: z.enum(['status', 'log', 'diff', 'branch', 'show', 'blame']), path: z.string().optional().default('.'), short: z.boolean().optional().default(false), staged: z.boolean().optional().default(false), file: z.string().optional(), unified: z.number().optional().default(3), limit: z.number().optional().default(10), oneline: z.boolean().optional().default(false), graph: z.boolean().optional().default(false), author: z.string().optional(), since: z.string().optional(), remote: z.boolean().optional().default(false), all: z.boolean().optional().default(false), commit: z.string().optional().default('HEAD'), stat: z.boolean().optional().default(false), lineStart: z.number().optional(), lineEnd: z.number().optional() }); async function runGitCommand(cwd: string, command: string): Promise<string> { try { const { stdout, stderr } = await execAsync(command, { cwd, maxBuffer: 10 * 1024 * 1024 }); if (stderr && !stderr.includes('warning:')) logger.warn(`Git stderr: ${stderr}`); return stdout.trim(); } catch (error) { const execError = error as { stderr?: string; stdout?: string }; throw new Error(`Git command failed: ${execError.stderr || execError.stdout || 'Unknown error'}`); } } export const tools = [{ name: 'git', description: 'Unified git tool. Use command: status|log|diff|branch|show|blame', inputSchema: zodToJsonSchema(GitArgsSchema) as ToolInput }]; export const handlers: Record<string, HandlerFunction> = { async git(args: Record<string, unknown>): Promise<MCPResponse> { const parsed = GitArgsSchema.safeParse(args); if (!parsed.success) throw new Error(`Invalid arguments: ${parsed.error}`); const validPath = await validatePath(parsed.data.path); switch(parsed.data.command) { case 'status': return handleStatus(validPath, parsed.data); case 'log': return handleLog(validPath, parsed.data); case 'diff': return handleDiff(validPath, parsed.data); case 'branch': return handleBranch(validPath, parsed.data); case 'show': return handleShow(validPath, parsed.data); case 'blame': return handleBlame(parsed.data); default: throw new Error('Invalid git command'); } } }; type GitArgs = z.infer<typeof GitArgsSchema>; async function handleStatus(cwd: string, data: GitArgs): Promise<MCPResponse> { const flags = data.short ? '--short --branch' : ''; const output = await runGitCommand(cwd, `git status ${flags}`); return { content: [{ type: 'text', text: output || 'No git status output' }] }; } async function handleLog(cwd: string, data: GitArgs): Promise<MCPResponse> { const flags: string[] = []; if (data.oneline) flags.push('--oneline'); if (data.graph) flags.push('--graph'); if (data.author) flags.push(`--author="${data.author}"`); if (data.since) flags.push(`--since="${data.since}"`); flags.push(`-n ${data.limit}`); const output = await runGitCommand(cwd, `git log ${flags.join(' ')}`); return { content: [{ type: 'text', text: output || 'No commits found' }] }; } async function handleDiff(cwd: string, data: GitArgs): Promise<MCPResponse> { const stagedFlag = data.staged ? '--staged' : ''; const fileArg = data.file ? `-- ${data.file}` : ''; const output = await runGitCommand(cwd, `git diff ${stagedFlag} --unified=${data.unified} ${fileArg}`); return { content: [{ type: 'text', text: output || 'No changes to show' }] }; } async function handleBranch(cwd: string, data: GitArgs): Promise<MCPResponse> { let flags = '-v'; if (data.all) flags = '-a -v'; else if (data.remote) flags = '-r -v'; const output = await runGitCommand(cwd, `git branch ${flags}`); return { content: [{ type: 'text', text: output || 'No branches found' }] }; } async function handleShow(cwd: string, data: GitArgs): Promise<MCPResponse> { const flags = data.stat ? '--stat' : ''; const output = await runGitCommand(cwd, `git show ${flags} ${data.commit}`); return { content: [{ type: 'text', text: output || 'No commit details found' }] }; } async function handleBlame(data: GitArgs): Promise<MCPResponse> { if (!data.file) throw new Error('file is required for blame command'); const validPath = await validatePath(data.file); const lineRange = (data.lineStart && data.lineEnd) ? `-L ${data.lineStart},${data.lineEnd}` : ''; const output = await runGitCommand('.', `git blame ${lineRange} ${validPath}`); return { content: [{ type: 'text', text: output || 'No blame information found' }] }; }