LODA API MCP Server

Instructions

Implementation Reference

• src/index.ts:532-550 (handler)

  The primary handler function for the 'eval_program' tool. It validates the input arguments, calls the LODA API client to evaluate the program, formats the result or error, and returns it in the MCP response format.

  private async handleEvalProgram(args: { code: string; t?: number; o?: number }) {
    const { code, t, o } = args;
    if (!code || typeof code !== 'string') {
      throw new McpError(ErrorCode.InvalidParams, "code is required");
    }
    const result = await this.apiClient.evalProgram(code, t, o);
    return {
      content: [
        {
          type: "text",
          text:
            result.status === "success"
              ? `Result: ${result.terms.join(', ')}`
              : `Error: ${result.message}${result.terms && result.terms.length ? `\nPartial result: ${result.terms.join(', ')}` : ''}`
        }
      ],
      ...result
    };
  }

• src/index.ts:285-294 (schema)

  Input schema definition for the 'eval_program' tool, specifying the required 'code' parameter and optional 't' (terms) and 'o' (offset) parameters with validation rules.

  inputSchema: {
    type: "object",
    properties: {
      code: { type: "string", description: "LODA program code in plain text format." },
      t: { type: "number", description: "Number of terms to compute" , minimum: 1, maximum: 10000 },
      o: { type: "number", description: "The starting index (offset) for evaluating the sequence program. Overrides #offset directive or defaults to 0." }
    },
    required: ["code"],
    additionalProperties: false
  }

• src/index.ts:415-416 (registration)

  Switch statement case that registers and routes incoming calls to the 'eval_program' tool handler within the CallToolRequestSchema handler.

  case "eval_program":
    return this.handleEvalProgram(safeArgs as { code: string; t?: number; o?: number });

• src/index.ts:156-165 (helper)

  Supporting API client method in LODAApiClient that performs the actual HTTP POST request to the LODA API endpoint /programs/eval to evaluate the provided program code.

  async evalProgram(code: string, t?: number, o?: number): Promise<Result> {
    const params = new URLSearchParams();
    if (t !== undefined) params.append('t', String(t));
    if (o !== undefined) params.append('o', String(o));
    return this.makeRequest(`/programs/eval${params.size ? '?' + params.toString() : ''}`, {
      method: 'POST',
      headers: { 'Content-Type': 'text/plain' },
      body: code,
    });
  }

• src/index.ts:282-295 (registration)

  Tool registration object in the ListTools response, defining the name, description, and input schema for 'eval_program'.

  {
    name: "eval_program",
    description: "Evaluate a LODA program to generate the corresponding integer sequence. The request body should contain the program code in plain text format. Optionally specify the number of terms and offset.",
    inputSchema: {
      type: "object",
      properties: {
        code: { type: "string", description: "LODA program code in plain text format." },
        t: { type: "number", description: "Number of terms to compute" , minimum: 1, maximum: 10000 },
        o: { type: "number", description: "The starting index (offset) for evaluating the sequence program. Overrides #offset directive or defaults to 0." }
      },
      required: ["code"],
      additionalProperties: false
    }
  },