mcp-ssh-tool

Instructions

Implementation Reference

• src/fs-tools.ts:10-35 (handler)

  The handler function 'readFile' that implements the 'fs_read' tool logic.

  export async function readFile(
    sessionId: string,
    path: string,
    encoding: string = 'utf8'
  ): Promise<string> {
    logger.debug('Reading file', { sessionId, path, encoding });
    
    const session = sessionManager.getSession(sessionId);
    if (!session) {
      throw new Error(`Session ${sessionId} not found or expired`);
    }
    
    try {
      const data = await session.sftp.get(path);
      const result = Buffer.isBuffer(data) ? data.toString(encoding as any) : String(data);
      logger.debug('File read successfully', { sessionId, path, size: result.length });
      return result;
    } catch (error) {
      logger.error('Failed to read file', { sessionId, path, error });
      throw wrapError(
        error,
        ErrorCode.EFS,
        `Failed to read file ${path}. Check if the file exists and is readable.`
      );
    }
  }

• src/types.ts:245-249 (schema)

  Zod schema for input validation for the 'fs_read' tool.

  export const FSReadSchema = z.object({
    sessionId: z.string().min(1),
    path: z.string().min(1),
    encoding: z.string().optional().default('utf8')
  });

• src/mcp.ts:179-190 (registration)

  Registration of the 'fs_read' tool in the MCP server setup.

    name: 'fs_read',
    description: 'Reads a file from the remote system',
    inputSchema: {
      type: 'object',
      properties: {
        sessionId: { type: 'string', description: 'SSH session ID' },
        path: { type: 'string', description: 'File path to read' },
        encoding: { type: 'string', description: 'File encoding (default: utf8)' }
      },
      required: ['sessionId', 'path']
    }
  },

• src/mcp.ts:426-431 (handler)

  The case block in 'setupToolHandlers' that routes the 'fs_read' request to the 'readFile' handler.

  case 'fs_read': {
    const params = FSReadSchema.parse(args);
    const result = await readFile(params.sessionId, params.path, params.encoding);
    logger.info('File read', { sessionId: params.sessionId, path: params.path });
    return { content: [{ type: 'text', text: JSON.stringify(result, null, 2) }] };
  }