Pump.fun MCP Server

Instructions

Implementation Reference

• src/sell-token.ts:15-141 (handler)

  The core handler function that executes the sell token logic: initializes SDK, handles keypairs, checks balances, calls sdk.sell, and returns transaction results.
  export async function sellToken( tokenAddress: string, sellAmount: number = 0, accountName: string = "default", slippageBasisPoints: number = 100 ) { try { console.error("Starting sellToken function"); const { sdk, connection } = initializeSDK(); console.error("SDK initialized"); const keysFolder = path.resolve(rootDir, ".keys"); console.error(`Using keys folder path relative to script: ${keysFolder}`); console.error( `Checking if keys folder exists: ${fs.existsSync(keysFolder)}` ); if (!fs.existsSync(keysFolder)) { console.error(`Creating keys folder: ${keysFolder}`); try { fs.mkdirSync(keysFolder, { recursive: true }); console.error(`Keys folder created successfully`); } catch (mkdirError: any) { console.error(`Error creating keys folder:`, mkdirError); return { success: false, error: `Error creating keys folder: ${ mkdirError.message || JSON.stringify(mkdirError) }`, }; } } console.error(`Getting or creating keypair from folder: ${keysFolder}`); const account = getOrCreateKeypair(keysFolder, accountName); console.log(`Using account: ${account.publicKey.toString()}`); const mintPublicKey = new PublicKey(tokenAddress); console.log(`Token address: ${tokenAddress}`); const tokenBalance = await getSPLBalance( connection, mintPublicKey, account.publicKey ); console.log(`Current token balance: ${tokenBalance}`); if (!tokenBalance || tokenBalance === 0) { const errorMessage = `No tokens to sell. Account ${account.publicKey.toString()} has 0 tokens of ${tokenAddress}.`; console.error(errorMessage); return { success: false, error: errorMessage }; } const amountToSell = sellAmount === 0 ? tokenBalance : Math.min(sellAmount, tokenBalance); console.log(`Amount to sell: ${amountToSell}`); const initialSolBalance = await connection.getBalance(account.publicKey); console.log( `Initial SOL balance: ${initialSolBalance / LAMPORTS_PER_SOL} SOL` ); console.log(`Selling ${amountToSell} tokens...`); const result = await sdk.sell( account, mintPublicKey, BigInt(amountToSell * Math.pow(10, 6)), BigInt(slippageBasisPoints), DEFAULT_PRIORITY_FEES ); if (!result.success) { console.error(`Failed to sell token:`, result.error); return { success: false, error: result.error ? typeof result.error === "object" ? JSON.stringify(result.error) : result.error : "Unknown error", }; } console.log(`Transaction successful: ${result.signature}`); const newSolBalance = await connection.getBalance(account.publicKey); console.log(`New SOL balance: ${newSolBalance / LAMPORTS_PER_SOL} SOL`); const solReceived = (newSolBalance - initialSolBalance) / LAMPORTS_PER_SOL; console.log(`SOL received: ${solReceived} SOL`); const newTokenBalance = (await getSPLBalance(connection, mintPublicKey, account.publicKey)) || 0; console.log(`New token balance: ${newTokenBalance}`); return { success: true, tokenAddress, tokensSold: amountToSell, solReceived, newTokenBalance, signature: result.signature, pumpfunUrl: `https://pump.fun/${tokenAddress}`, }; } catch (error: any) { console.error("Error selling token:", error); console.error("Error stack:", error.stack); let errorMessage = "Unknown error"; if (error) { if (typeof error === "object") { if (error.message) { errorMessage = error.message; } else { try { errorMessage = JSON.stringify(error); } catch (e) { errorMessage = "Error object could not be stringified"; } } } else { errorMessage = String(error); } } return { success: false, error: errorMessage }; } }
• src/index.ts:195-242 (registration)

  Registers the 'sell-token' tool with MCP server, including input schema, description, and wrapper handler that calls the core sellToken function.
  server.tool( "sell-token", "Sell a Pump.fun token", { tokenAddress: z.string().describe("The token's mint address"), sellAmount: z .number() .min(0) .describe("Amount of tokens to sell (0 for all)"), accountName: z .string() .default("default") .describe("Name of the account to use"), slippageBasisPoints: z .number() .default(100) .describe("Slippage tolerance in basis points (1% = 100)"), }, async ({ tokenAddress, sellAmount, accountName, slippageBasisPoints }) => { try { console.error( `Selling token: ${tokenAddress}, amount: ${ sellAmount === 0 ? "ALL" : sellAmount }` ); const result = await sellToken( tokenAddress, sellAmount, accountName, slippageBasisPoints ); const formattedResult = formatSellResult(result); return createMcpResponse(formattedResult); } catch (error: any) { console.error("Error selling token:", error); return { content: [ { type: "text" as const, text: `Error selling token: ${error?.message || "Unknown error"}`, }, ], }; } }
• src/index.ts:198-212 (schema)

  Zod schema defining input parameters for the sell-token tool.
  { tokenAddress: z.string().describe("The token's mint address"), sellAmount: z .number() .min(0) .describe("Amount of tokens to sell (0 for all)"), accountName: z .string() .default("default") .describe("Name of the account to use"), slippageBasisPoints: z .number() .default(100) .describe("Slippage tolerance in basis points (1% = 100)"), },
• src/sell-token.ts:143-159 (helper)

  Helper function to format the sell token result into a human-readable string.
  export function formatSellResult( result: ReturnType<typeof sellToken> extends Promise<infer T> ? T : never ) { if (!result.success) { return `Error selling token: ${result.error}`; } return [ `Successfully sold token!`, `Token Address: ${result.tokenAddress}`, `Tokens Sold: ${result.tokensSold}`, `SOL Received: ${result.solReceived} SOL`, `Remaining Token Balance: ${result.newTokenBalance}`, `Transaction Signature: ${result.signature}`, `Pump.fun URL: ${result.pumpfunUrl}`, ].join("\n"); }