MCP Server for FTP Access

Instructions

Implementation Reference

• src/index.ts:99-130 (registration)

  Registration of the 'upload-file' MCP tool using server.tool(). Includes input schema (remotePath, content) and inline handler that calls ftpClient.uploadFile() and returns formatted text response.

  server.tool(
    "upload-file",
    "Upload a file to the FTP server",
    {
      remotePath: z.string().describe("Destination path on the FTP server"),
      content: z.string().describe("Content to upload to the file"),
    },
    async ({ remotePath, content }) => {
      try {
        await ftpClient.uploadFile(remotePath, content);
        
        return {
          content: [
            {
              type: "text",
              text: `File successfully uploaded to ${remotePath}`
            }
          ]
        };
      } catch (error) {
        return {
          isError: true,
          content: [
            {
              type: "text",
              text: `Error uploading file: ${error instanceof Error ? error.message : String(error)}`
            }
          ]
        };
      }
    }
  );

• src/index.ts:102-105 (schema)

  Zod input schema defining parameters for the upload-file tool: remotePath (destination path) and content (file content as string).

  {
    remotePath: z.string().describe("Destination path on the FTP server"),
    content: z.string().describe("Content to upload to the file"),
  },

• src/index.ts:106-129 (handler)

  Inline handler function for upload-file tool: invokes ftpClient.uploadFile with parameters and returns MCP-formatted success or error response.

  async ({ remotePath, content }) => {
    try {
      await ftpClient.uploadFile(remotePath, content);
      
      return {
        content: [
          {
            type: "text",
            text: `File successfully uploaded to ${remotePath}`
          }
        ]
      };
    } catch (error) {
      return {
        isError: true,
        content: [
          {
            type: "text",
            text: `Error uploading file: ${error instanceof Error ? error.message : String(error)}`
          }
        ]
      };
    }
  }

• src/ftp-client.ts:97-117 (helper)

  Core FTP upload logic in FtpClient class: writes content to temp file, uses basic-ftp Client.uploadFrom to upload to remotePath, handles connection and cleanup.

  async uploadFile(remotePath: string, content: string): Promise<boolean> {
    try {
      await this.connect();
      
      // Create a temporary file with the content
      const tempFilePath = path.join(this.tempDir, `upload-${Date.now()}-${path.basename(remotePath)}`);
      fs.writeFileSync(tempFilePath, content);
      
      // Upload the file
      await this.client.uploadFrom(tempFilePath, remotePath);
      
      // Clean up
      fs.unlinkSync(tempFilePath);
      
      await this.disconnect();
      return true;
    } catch (error) {
      console.error("Upload file error:", error);
      throw new Error(`Failed to upload file: ${error instanceof Error ? error.message : String(error)}`);
    }
  }