solanaprox-mcp

Instructions

Implementation Reference

• src/index.ts:298-322 (handler)

  The handler for the 'estimate_cost' tool - extracts arguments (prompt, model, max_tokens) and calls estimateCostFromPrompt to calculate the estimated cost, then returns a formatted response with the cost estimate.

  case "estimate_cost": {
    const { prompt, model, max_tokens } = args as any;
    const cost = estimateCostFromPrompt(
      prompt,
      model || "claude-sonnet-4-20250514",
      max_tokens || 1024
    );
  
    return {
      content: [
        {
          type: "text",
          text: [
            `💵 Cost Estimate`,
            `Model: ${model || "claude-sonnet-4-20250514"}`,
            `Prompt length: ~${Math.ceil(prompt.length / 4)} tokens`,
            `Max output: ${max_tokens || 1024} tokens`,
            `Estimated cost: ~$${cost.toFixed(6)} USDC`,
            ``,
            `Note: Cached responses get 50% discount`,
          ].join("\n"),
        },
      ],
    };
  }

• src/index.ts:77-101 (schema)

  The schema definition for the 'estimate_cost' tool - defines input parameters (prompt, model, max_tokens) with their types, descriptions, and defaults. Prompt is required.

  {
    name: "estimate_cost",
    description:
      "Estimate the cost of an AI request before making it. Returns estimated USD cost based on prompt length and model.",
    inputSchema: {
      type: "object",
      properties: {
        prompt: {
          type: "string",
          description: "The prompt to estimate cost for",
        },
        model: {
          type: "string",
          description: "Model to use for estimation",
          default: "claude-sonnet-4-20250514",
        },
        max_tokens: {
          type: "number",
          description: "Expected max tokens in response",
          default: 1024,
        },
      },
      required: ["prompt"],
    },
  },

• src/index.ts:214-227 (helper)

  The estimateCostFromPrompt helper function - estimates input tokens from prompt length (4 chars per token), assumes output tokens are half of max_tokens, and calls estimateCostFromTokens to calculate the final cost.

  function estimateCostFromPrompt(
    prompt: string,
    model: string,
    maxTokens: number
  ): number {
    // Rough estimate: 4 chars per token
    const estimatedInputTokens = Math.ceil(prompt.length / 4);
    const estimatedOutputTokens = maxTokens / 2; // assume half of max
    return estimateCostFromTokens(
      model,
      estimatedInputTokens,
      estimatedOutputTokens
    );
  }

• src/index.ts:198-212 (helper)

  The estimateCostFromTokens helper function - calculates USD cost based on per-million-token pricing for different models (Claude Sonnet, GPT-4 Turbo), with a 20% markup noted in comments.

  function estimateCostFromTokens(
    model: string,
    inputTokens: number,
    outputTokens: number
  ): number {
    // Pricing per 1M tokens (with 20% markup)
    const pricing: Record<string, { input: number; output: number }> = {
      "claude-sonnet-4-20250514": { input: 3.6, output: 18.0 },
      "claude-3-5-sonnet-20241022": { input: 3.6, output: 18.0 },
      "gpt-4-turbo": { input: 12.0, output: 36.0 },
    };
  
    const p = pricing[model] || { input: 3.6, output: 18.0 };
    return (inputTokens * p.input + outputTokens * p.output) / 1_000_000;
  }

• src/index.ts:30-112 (registration)

  The tools array containing all tool definitions including 'estimate_cost', which is registered along with 'ask_ai', 'check_balance', and 'list_models'.

  const tools: Tool[] = [
    {
      name: "ask_ai",
      description:
        "Send a prompt to an AI model via SolanaProx. Costs are automatically deducted from your Solana wallet balance in USDC. Supports Claude and GPT-4 models. Use this for any AI inference task.",
      inputSchema: {
        type: "object",
        properties: {
          prompt: {
            type: "string",
            description: "The prompt or question to send to the AI model",
          },
          model: {
            type: "string",
            description:
              "AI model to use. Options: claude-sonnet-4-20250514 (default), gpt-4-turbo",
            default: "claude-sonnet-4-20250514",
          },
          max_tokens: {
            type: "number",
            description: "Maximum tokens in response (default: 1024, max: 4096)",
            default: 1024,
          },
          system: {
            type: "string",
            description: "Optional system prompt to set context for the AI",
          },
        },
        required: ["prompt"],
      },
    },
    {
      name: "check_balance",
      description:
        "Check your current SolanaProx balance. Returns available USDC and SOL balance that can be used for AI requests.",
      inputSchema: {
        type: "object",
        properties: {
          wallet: {
            type: "string",
            description:
              "Solana wallet address to check. Defaults to configured wallet.",
          },
        },
        required: [],
      },
    },
    {
      name: "estimate_cost",
      description:
        "Estimate the cost of an AI request before making it. Returns estimated USD cost based on prompt length and model.",
      inputSchema: {
        type: "object",
        properties: {
          prompt: {
            type: "string",
            description: "The prompt to estimate cost for",
          },
          model: {
            type: "string",
            description: "Model to use for estimation",
            default: "claude-sonnet-4-20250514",
          },
          max_tokens: {
            type: "number",
            description: "Expected max tokens in response",
            default: 1024,
          },
        },
        required: ["prompt"],
      },
    },
    {
      name: "list_models",
      description:
        "List all available AI models on SolanaProx with their pricing.",
      inputSchema: {
        type: "object",
        properties: {},
        required: [],
      },
    },
  ];