SuperCollider MCP Server

Instructions

Implementation Reference

• src/index.ts:68-81 (registration)

  Registration of the 'sc_execute' tool including name, description, and input schema.

  {
    name: 'sc_execute',
    description: 'Execute raw SuperCollider code. Use this for advanced synthesis control or custom SynthDefs.',
    inputSchema: {
      type: 'object',
      properties: {
        code: {
          type: 'string',
          description: 'The SuperCollider code to execute',
        },
      },
      required: ['code'],
    },
  },

• src/index.ts:293-308 (handler)

  Handler for 'sc_execute' tool: validates input, checks server status, executes code via scServer.executeCode, returns result.

  case 'sc_execute': {
    const schema = z.object({ code: z.string() });
    const { code } = schema.parse(args);
  
    if (!scServer.getBooted()) {
      return {
        content: [{ type: 'text', text: 'Error: SuperCollider server is not running. Call sc_boot first.' }],
        isError: true,
      };
    }
  
    const result = await scServer.executeCode(code);
    return {
      content: [{ type: 'text', text: result || 'Code executed successfully' }],
    };
  }

• src/supercollider.ts:154-189 (helper)

  Core implementation: SuperColliderServer.executeCode method sends code to sclang stdin, captures stdout/stderr after 500ms timeout.

  async executeCode(code: string): Promise<string> {
    if (!this.sclangProcess?.stdin) {
      throw new Error('SuperCollider sclang process is not running');
    }
  
    return new Promise((resolve, reject) => {
      let output = '';
      let errorOutput = '';
  
      const stdoutHandler = (data: Buffer) => {
        output += data.toString();
      };
  
      const stderrHandler = (data: Buffer) => {
        errorOutput += data.toString();
      };
  
      this.sclangProcess!.stdout?.on('data', stdoutHandler);
      this.sclangProcess!.stderr?.on('data', stderrHandler);
  
      // Send the code
      this.sclangProcess!.stdin!.write(code + '\n');
  
      // Wait for output (this is a simple approach; a more robust solution would parse responses)
      setTimeout(() => {
        this.sclangProcess!.stdout?.removeListener('data', stdoutHandler);
        this.sclangProcess!.stderr?.removeListener('data', stderrHandler);
  
        if (errorOutput) {
          reject(new Error(errorOutput));
        } else {
          resolve(output);
        }
      }, 500);
    });
  }

• src/index.ts:71-80 (schema)

  Input schema definition for sc_execute tool (MCP JSON schema).

  inputSchema: {
    type: 'object',
    properties: {
      code: {
        type: 'string',
        description: 'The SuperCollider code to execute',
      },
    },
    required: ['code'],
  },