Qwen3-Coder MCP Server

Instructions

Implementation Reference

• qwen3-mcp-server.js:206-217 (handler)

  Handler logic for the 'qwen3_code_fix' tool: constructs a specific prompt including the buggy code, optional error message, and language, then invokes the callQwen3Coder helper to get the fix from the Qwen3-Coder model.

        case "qwen3_code_fix":
          prompt = `Fix the following ${args.language || 'code'} that has a bug:
  
  \`\`\`${args.language || ''}
  ${args.code}
  \`\`\`
  
  ${args.error ? `Error/Issue: ${args.error}` : ''}
  
  Please provide the corrected code with explanations of what was wrong and how it was fixed.`;
          result = await callQwen3Coder(prompt);
          break;

• qwen3-mcp-server.js:119-136 (schema)

  Input schema for the qwen3_code_fix tool, specifying required 'code' parameter and optional 'error' and 'language'.

  inputSchema: {
    type: "object",
    properties: {
      code: {
        type: "string",
        description: "The buggy code to fix"
      },
      error: {
        type: "string",
        description: "Error message or description of the bug"
      },
      language: {
        type: "string",
        description: "Programming language of the code"
      }
    },
    required: ["code"]
  }

• qwen3-mcp-server.js:116-137 (registration)

  Registration of the qwen3_code_fix tool within the listTools response, defining name, description, and input schema.

  {
    name: "qwen3_code_fix",
    description: "Fix bugs in code using Qwen3-Coder",
    inputSchema: {
      type: "object",
      properties: {
        code: {
          type: "string",
          description: "The buggy code to fix"
        },
        error: {
          type: "string",
          description: "Error message or description of the bug"
        },
        language: {
          type: "string",
          description: "Programming language of the code"
        }
      },
      required: ["code"]
    }
  },

• qwen3-mcp-server.js:25-56 (helper)

  Helper function that spawns an Ollama process to run the 'qwen3-coder:30b' model with the given prompt, capturing output and handling errors/timeouts. Used by all tools including qwen3_code_fix.

  async function callQwen3Coder(prompt, options = {}) {
    return new Promise((resolve, reject) => {
      const ollamaProcess = spawn('ollama', ['run', 'qwen3-coder:30b', prompt], {
        stdio: ['pipe', 'pipe', 'pipe']
      });
  
      let output = '';
      let error = '';
  
      ollamaProcess.stdout.on('data', (data) => {
        output += data.toString();
      });
  
      ollamaProcess.stderr.on('data', (data) => {
        error += data.toString();
      });
  
      ollamaProcess.on('close', (code) => {
        if (code === 0) {
          resolve(output.trim());
        } else {
          reject(new Error(`Ollama process exited with code ${code}: ${error}`));
        }
      });
  
      // Set timeout for long-running requests
      setTimeout(() => {
        ollamaProcess.kill();
        reject(new Error('Request timeout'));
      }, options.timeout || 120000); // 2 minutes default timeout
    });
  }