MCP SSH Server

Instructions

Implementation Reference

• src/index.ts:1250-1291 (handler)

  Implements the core logic for the ssh_set_working_directory tool: parses input using schema, retrieves connection context, verifies directory existence via SSH command, updates currentWorkingDirectory in context, and returns success message.

  private async handleSetWorkingDirectory(args: unknown) {
    const params = SetWorkingDirectorySchema.parse(args);
    
    const context = connectionContexts.get(params.connectionId);
    if (!context) {
      throw new McpError(
        ErrorCode.InvalidParams,
        `Connection ID '${params.connectionId}' not found`
      );
    }
  
    try {
      // Verify the directory exists
      const result = await context.ssh.execCommand(`test -d "${params.workingDirectory}" && echo "exists"`);
      if (result.code !== 0) {
        throw new McpError(
          ErrorCode.InvalidParams,
          `Directory '${params.workingDirectory}' does not exist or is not accessible`
        );
      }
  
      // Set the working directory
      context.currentWorkingDirectory = params.workingDirectory;
      
      return {
        content: [
          {
            type: 'text',
            text: `Working directory set to: ${params.workingDirectory}`,
          },
        ],
      };
    } catch (error) {
      if (error instanceof McpError) {
        throw error;
      }
      throw new McpError(
        ErrorCode.InternalError,
        `Failed to set working directory: ${error instanceof Error ? error.message : String(error)}`
      );
    }
  }

• src/index.ts:148-151 (schema)

  Zod schema defining input parameters for ssh_set_working_directory: connectionId (string) and workingDirectory (string). Used for validation in the handler.

  const SetWorkingDirectorySchema = z.object({
    connectionId: z.string().describe('SSH connection ID'),
    workingDirectory: z.string().describe('Working directory path to set as current')
  });

• src/index.ts:420-431 (registration)

  Tool metadata registration in ListToolsRequestSchema handler, specifying name, description, and inputSchema advertised to clients.

  {
    name: 'ssh_set_working_directory',
    description: 'Set the current working directory for a connection',
    inputSchema: {
      type: 'object',
      properties: {
        connectionId: { type: 'string', description: 'SSH connection ID' },
        workingDirectory: { type: 'string', description: 'Working directory path to set as current' }
      },
      required: ['connectionId', 'workingDirectory']
    },
  },

• src/index.ts:513-514 (registration)

  Dispatch registration in CallToolRequestSchema switch statement, routing calls to the handler function.

  case 'ssh_set_working_directory':
    return await this.handleSetWorkingDirectory(args);