Blockchain MCP Server

Instructions

Implementation Reference

• src/rpc-service/index.ts:95-158 (handler)

  Handler function that performs the static call to the contract using the ethers JsonRpcProvider.

        async ({ chain, to, data, blockTag = "latest" }) => {
          try {
            const chainConfig = DEFAULT_CHAINS[chain.toLowerCase()];
            if (!chainConfig) {
              return {
                content: [{
                  type: "text",
                  text: `Error: Unsupported chain "${chain}". Available chains: ${Object.keys(DEFAULT_CHAINS).join(', ')}`
                }],
                isError: true
              };
            }
  
            if (!ethers.isAddress(to)) {
              return {
                content: [{
                  type: "text",
                  text: `Error: Invalid contract address: ${to}`
                }],
                isError: true
              };
            }
  
            const provider = this.providers.get(chain.toLowerCase());
            if (!provider) {
              return {
                content: [{
                  type: "text",
                  text: `Error: Provider not initialized for chain: ${chain}`
                }],
                isError: true
              };
            }
  
            const result = await provider.call({
              to: to,
              data: data
            });
  
            return {
              content: [{
                type: "text",
                text: `Static call result:
  
  🔗 Chain: ${chainConfig.name} (${chainConfig.chainId})
  📄 Contract: ${to}
  📊 Call Data: ${data}
  🏷️ Block: ${blockTag}
  
  📤 Result: ${result}
  
  ${chainConfig.explorerUrl ? `🔍 Explorer: ${chainConfig.explorerUrl}/address/${to}` : ''}`
              }]
            };
          } catch (error) {
            return {
              content: [{
                type: "text",
                text: `Error making static call: ${error instanceof Error ? error.message : String(error)}`
              }],
              isError: true
            };
          }
        }

• src/rpc-service/index.ts:89-93 (schema)

  Input schema using Zod for validating chain, contract address, call data, and optional block tag.

    chain: z.string().describe(`Chain identifier. Available: ${Object.keys(DEFAULT_CHAINS).join(', ')}`),
    to: z.string().describe("Contract address to call"),
    data: z.string().describe("ABI-encoded function call data"),
    blockTag: z.string().optional().describe("Block tag (latest, earliest, pending, or block number)").default("latest")
  }

• src/rpc-service/index.ts:83-159 (registration)

  Registers the 'static-call' tool with the MCP server, providing schema and handler.

      server.registerTool(
        "static-call",
        {
          title: "Static Call",
          description: "Make a static call to a smart contract on any EVM-compatible chain (read-only)",
          inputSchema: {
            chain: z.string().describe(`Chain identifier. Available: ${Object.keys(DEFAULT_CHAINS).join(', ')}`),
            to: z.string().describe("Contract address to call"),
            data: z.string().describe("ABI-encoded function call data"),
            blockTag: z.string().optional().describe("Block tag (latest, earliest, pending, or block number)").default("latest")
          }
        },
        async ({ chain, to, data, blockTag = "latest" }) => {
          try {
            const chainConfig = DEFAULT_CHAINS[chain.toLowerCase()];
            if (!chainConfig) {
              return {
                content: [{
                  type: "text",
                  text: `Error: Unsupported chain "${chain}". Available chains: ${Object.keys(DEFAULT_CHAINS).join(', ')}`
                }],
                isError: true
              };
            }
  
            if (!ethers.isAddress(to)) {
              return {
                content: [{
                  type: "text",
                  text: `Error: Invalid contract address: ${to}`
                }],
                isError: true
              };
            }
  
            const provider = this.providers.get(chain.toLowerCase());
            if (!provider) {
              return {
                content: [{
                  type: "text",
                  text: `Error: Provider not initialized for chain: ${chain}`
                }],
                isError: true
              };
            }
  
            const result = await provider.call({
              to: to,
              data: data
            });
  
            return {
              content: [{
                type: "text",
                text: `Static call result:
  
  🔗 Chain: ${chainConfig.name} (${chainConfig.chainId})
  📄 Contract: ${to}
  📊 Call Data: ${data}
  🏷️ Block: ${blockTag}
  
  📤 Result: ${result}
  
  ${chainConfig.explorerUrl ? `🔍 Explorer: ${chainConfig.explorerUrl}/address/${to}` : ''}`
              }]
            };
          } catch (error) {
            return {
              content: [{
                type: "text",
                text: `Error making static call: ${error instanceof Error ? error.message : String(error)}`
              }],
              isError: true
            };
          }
        }
      );