Cowsay MCP Server

Instructions

Implementation Reference

• src/index.ts:59-77 (handler)

  The handler function that executes the cowsay tool logic: validates access, lowercases inputs if configured, calls generateCowsay helper, and returns the ASCII art as text content.

  }, async ({ message, character }) => {
      // Validate server access
      if (!validateServerAccess(config.serverToken)) {
          throw new Error("Server access validation failed. Please provide a valid serverToken.");
      }
      // Apply user preferences from config
      const searchText = config.caseSensitive ? message : message.toLowerCase();
      const searchChar = config.caseSensitive ? character : character.toLowerCase();
      // Count occurrences of the specific character
      const result = await generateCowsay(searchText, searchChar);
      return {
          content: [
              {
                  type: "text",
                  text: result
              }
          ],
      };
  })

• src/index.ts:151-165 (helper)

  Core helper function implementing cowsay logic: prefers executing 'npx cowsay' via child_process, falls back to 'cowsay' library's say() method.

  export async function generateCowsay(message: string, cow: string): Promise<string> {
      try {
          const cowOption = cow !== 'default' ? `-f ${cow}` : '';
          const escapedMessage = message.replace(/'/g, "\\'");
          const { stdout } = await execAsync(`echo '${escapedMessage}' | npx cowsay@1.6.0 ${cowOption}`);
          return stdout;
      } catch (error) {
          try {
              const options = cow !== 'default' ? { f: cow } : {};
              return cowsay.say({ text: message, ...options });
          } catch (err) {
              throw new Error(`Failed to generate cowsay output: ${err instanceof Error ? err.message : String(err)}`);
          }
      }
  }

• src/tools.ts:3-78 (schema)

  Detailed JSON schema definition for the cowsay tool inputs, including message, character selection, custom eyes/tongue, and various cow face modes.

  export const COWSAY: Tool = {
    name: 'cowsay',
    title: 'Cow Say',
    description: 'Generate ASCII art of a cow saying something.',
    inputSchema: {
      type: 'object',
      properties: {
        message: {
          type: 'string',
          description: 'The message for the cow to say.',
          default: 'Hello World!'
        },
        character: {
          type: 'string',
          description: 'The cow character to use.',
          enum: ['default', 'small', 'tux', 'moose', 'sheep', 'dragon', 'elephant', 'skeleton', 'stimpy'],
          default: 'default'
        },
        e: {
          type: 'string',
          description: 'Custom eyes for the cow.',
          default: 'oo'
        },
        T: {
          type: 'string',
          description: 'Custom tongue for the cow.'
        },
        r: {
          type: 'boolean',
          description: 'Use a random cow character.',
          default: false
        },
        b: {
          type: 'boolean',
          description: 'Borg mode - use borg face.',
          default: false
        },
        d: {
          type: 'boolean',
          description: 'Dead mode - use dead face.',
          default: false
        },
        g: {
          type: 'boolean',
          description: 'Greedy mode - use greedy face.',
          default: false
        },
        p: {
          type: 'boolean',
          description: 'Paranoia mode - use paranoia face.',
          default: false
        },
        s: {
          type: 'boolean',
          description: 'Stoned mode - use stoned face.',
          default: false
        },
        t: {
          type: 'boolean',
          description: 'Tired mode - use tired face.',
          default: false
        },
        w: {
          type: 'boolean',
          description: 'Wired mode - use wired face.',
          default: false
        },
        y: {
          type: 'boolean',
          description: 'Youthful mode - use youthful face.',
          default: false
        }
      },
      required: ['message']
    },
  };

• src/index.ts:52-58 (registration)

  Registers the 'cowsay' tool with the MCP server, referencing title/description from tools.ts and providing a Zod-based input schema (simplified to message and character).

  mcp_server.registerTool("cowsay", {
      title: COWSAY.title,
      description: COWSAY.description,
      inputSchema: {
          message: z.string().describe('The message for the cow to say.'),
          character: z.string().optional().default('default').describe('The cow character to use.')
      },