Build, simulate, sign,
then send everywhere at once.
SDK
One ES module served from this site. You pass it the @solana/web3.js module and a Keypair, so the key stays where your bot runs, and sendFast goes from your machine straight to Jito and the RPC.
import * as web3 from "@solana/web3.js";
import { createFastlane } from "https://fastlanes.app/sdk/fastlane.mjs";
const fl = createFastlane({ site: "https://fastlanes.app", web3, keypair });
const built = await fl.buildTx({ kind: "buy", mint, lamports: 50_000_000 });
// built.simulation[0].ok is false when the price moved past slippage
const signed = fl.sign(built); // local, before you need it
const r = await fl.sendFast(signed); // { sig, status, ms, slot }MCP server
Streamable HTTP at https://fastlanes.app/mcp. Four tools: build_tx, simulate, send_fast and launcher. build_tx returns unsigned transactions with the fee, its Memo and the Jito tip already in; the agent signs them and send_fast fans them out. The server never sees a key.
{ "mcpServers": { "fastlane": { "url": "https://fastlanes.app/mcp" } } }The same fast path for bots and agents
Bots and AI agents get what the wallet does: the instructions for the trade, a simulation that sets the compute units, a local signature and a send to every Jito block engine at once. A launch and its first buy come as one bundle. The key never leaves the machine that signs.
Everything slow happens
before the click
Signed before you click
Each button keeps its next transaction built and signed on a blockhash at most 2.5 s old, with its compute-unit limit taken from the simulation, a priority fee and a Jito tip. It is rebuilt every 6 seconds so the price stays fresh.
Simulated, bad prices blocked
Every transaction is simulated before it is signed. A buy or sell whose price moved past your slippage, 3% by default, fails the simulation and is never sent, so it costs nothing.
Seven sends at the same moment
The click posts the signed bytes to six public Jito block engines and the RPC in parallel. The tip gets it ordered first, and no single slow endpoint can hold it back.
Launch and buy in one slot
A pump.fun create and your first buy go as one Jito bundle: both land in the same slot, in order, or neither does. Nobody can buy between your create and your buy.