FLEX-SDK is a library with convenient facade over the FLEX smart contract system and can be used by FLEX maintainers, FLEX traders and others.

The library is targeted to be used with Node.js applications.

Read the full Flex documentation here https://docs.everos.dev/flex

Initialize Flex object

Library setup is simple, it includes setup for the Everscale client and configuration of the FLEX SDK.

To get the address of Flex Super Root contract go to the GraphQL playground and run this query:


Now specify the endpoint URL and Super Root address in the config and initialize flex object with it. You will need flex object later:

import { TonClient } from "@eversdk/core";
import { libNode } from "@eversdk/lib-node";
import { Flex, FlexConfig } from "../flex";

const FLEX_CONFIG: Partial<FlexConfig> = {
evr: {
sdk: {
network: {
endpoints: ["FLEX ENDPOINT"],
superRoot: "Super Root address",
const flex = new Flex(FLEX_CONFIG);

About Signer parameter

Many functions of FLEX SDK accept parameters named signer. It is an object that has a secret, required to sign messages that will be sent to the blockchain.

signer parameter can accept these values:

  • String containing the secret key of the key pair required to sign messages. Secret key must be represented as a hex string with exactly 64 characters.

  • Instance of the Signer type from the @eversdk/core library.

  • Name of the signer in the everdev signer registry.

Manage Client and Traders

Before trading on FLEX you have to prepare some required FLEX actors: Client and Trader.

Client creation requires a wallet with EVER balance that will become an owner for Client contract used to perform management operations of Flex.

Good choice is a Multisig Wallet because it can send payloads to other contracts.

Owner contract means that only this contract can call functions of Client contract. One of the management funcstions is deploy of a Trader's contract.

Let's deploy Flex Client and then a Trader:

const clientAddress = await Client.deploy(flex, {
everWallet: {
address: "0:d807caf6df3a7c2bb0b64915613eca9d8f17ca1de0b938dfdcbb9b4ff30c4526",
signer: "everWallet private key",
signer: "Flex Client private key, can be the same with everWallet signer",

console.log(`Client: ${clientAddress}}`);

To deploy a Trader, a person or organization who becomes Trader must generate a pair of keys and profive Flex Client with the pubkey only.

If Flex Client will be its only Teader herself, than it can use its Client pubkey.

Then, Flex Client must generate some Trader ID (uint256) that must be unique for each its Trader.

We already generated some ID and have a Trader pubkey, let's deploy Trader contract:

// Client deploys Trader's contract (`userIdIndex` contract)

await Trader.deploy(flex, {
client: {
address: clientAddress,
signer: "Client private key",
id: traderId,
name: "any name",
pubkey: "162c6c708018da073729dd4a60118425dd917e44653383f1faed4d16b94af30b" // Trader's pubkey

Deposit on Flex

You can deposit EVERs and Tip3 tokens on Flex.

Deposit EVERs

To deposit evers, transfer them to the Ever Vault contract. Specify Trader ID.

let trader_ever_wallet =  await Trader.deployEverWallet(flex, {
clientAddress: clientAddress,
everWallet: {
address: "0:d677caf6df3a7c2bb0b64915613eca9d8f17ca1de0b938dfdcbb9b4ff30c4526",
signer: "everWallet",
tokens: 100,
evers: 20,
keepEvers: 15,
traderId: traderId,
wrapperAddress: "0:c072805ae38d548d4abbaddf929659d37584117b63b0969eb3f812c6252b12fb", // EVER wrapper address

console.log(`Trader EVER wallet address: ${trader_ever_wallet} has beed topped-up.`);

Deposit Tip3 tokens

To deposit Tip3 tokens, transfer them from Tip3 wallet to the Flex Vault contract. Specify Trader ID.

let trader_tip3_wallet =  await Trader.deployTip31Wallet(flex, {
clientAddress: clientAddress,
everWallet: {
address: "0:d677caf6df3a7c2bb0b64915613eca9d8f17ca1de0b938dfdcbb9b4ff30c4526",
signer: "everWallet",
traderId: traderId,
tokenWalletAddress: "0:d4208262595226ac069b94d716ec6339882ec93a0e7e254186f3eb77b7d34c4b", // tip3 wallet owned by everWallet
tokenWrapperAddress: "0:d51c96406f74e4a1168f5ca3a936330beb7653782743cdce23c11d285c92f9ca", // Token Wrapper address on Flex
tokenWrapperWalletAddress: "0:ca4a6787b720f38745ec2a13f997061a7ba3dfa2e9b4432771a9cf61ea6ac984", // tip3 vault contract of the Token Wrapper
tokenUnits: "100000000000", // tokens to deposit
transferEvers: 21,
evers: 20,
keepEvers: 15

console.log(`Trader Tip3 wallet address: ${trader_tip3_wallet} has beed topped-up.`);



Trader needs to have 2 wallets for each currency in a Pair to trade in that Pair. Go to the Deposit sections to read how to top-up token wallets.

await Trader.makeOrder(
clientAddress: clientAddress,
trader: {
id: traderId,
signer: `Trader's private key`
sell: true,
marketAddress: marketAddress, // Trading pair address
price: 2.6,
amount: 18,


You can examine the examples folder for a lot of examples. To build run

npm run build

To run an example do

cd dist/examples
node <example name>


The major part of library functionality is accessible via command line interface flex-cli.

To use command line interface run command npm run cli command [options] <arguments>.

You can get help on CLI running npm run cli --help.

Remarks for the FLEX SDK Developers

FLEX SDK contains folder contracts with TS wrappers of all contracts used in FLEX contract system. Please note that at the moment, Flex library syncronizes contracts from the private repository.

To update FLEX contract wrappers you have to perform following steps:

  • Clone ton-contracts repository aside of flex-sdk-js folder.
  • Checkout ton-contracts repo on required branch.
  • Run npm run update-contracts inside of flex-sdk-js folder.

After that step the flex-sdk-js library can stop to compile. You have to perform changes in library code to reflect changes in FLEX contract system if required.



npm i
npm run build

Unit Tests

npm t

Integration Tests


Create config file. Config file must be located and named as flex-sdk-js/.secret/integration-test-config.json.

"flex": {
"evr": {
"sdk": {
"network": {
"endpoints": [
"superRoot": "0:7a6d3ab04ab26333d6e0523410b60d9f4bc55913e4c0291010c8314e9e47d169"
"everWallet": {
"address": "<ever-wallet-address>",
"signer": "<ever-wallet-signer>"
"client": {
"address": "<flex-client-address>",
"signer": "<flex-client-signer>"
"trader": {
"signer": "<flex-trader-signer>"
"market": "0:a8f3f3bfafcac2adf95b62670aa01fbf610a103ce7029dc5f13cab4f0a7edfe8",
"EVER": {
"wrapper": "0:1cc3596e2db5cc92d0e02f55526f8aec949924ef320d72b763a5f4aafcca3e30",
"wallet": {
"address": "<ever-token-wallet-address>",
"signer": "<ever-token-wallet-signer>"
"TSDT": {
"wrapper": "0:b550a9138452d36d0a1e38edebac0063f3126e4d7a4cf593e6c090faa2ec0523",
"wrapperWallet": "0:c304ee549051d5500877f2fc796bb81e3f9cfde2b1b62de0eb360804ab7fe661",
"wallet": {
"address": "<tsdt-token-wallet-address>",
"signer": "<tsdt-token-wallet-signer>"


  • <ever-wallet-address> and <ever-wallet-signer> is a main ever wallet. If you omit address, it will be calculated from signer's public key. This wallet must have enough balance to perform all integration test.

  • <flex-client-address> and <flex-client-signer> is a FlexClient account.

  • <flex-trader-signer> is a traders keys used in trading operations. Public key of this signer is used as a traderId.

  • <ever-token-wallet-address> and <ever-token-wallet-signer> is a multisig wallet that will be used as an external EVER wallet.
    If you omit address, it will be calculated from signer's public key. Usually it is the same as a main ever wallet.

  • <tsdt-token-wallet-address> and <tsdt-token-wallet-signer> is a TSDT TIP3 Token Wallet that will be used as an external TSDT wallet. Usually this wallet is related to the main ever wallet. So <tsdt-token-wallet-signer> is equal to the <ever-wallet-signer>.

Recommended signer names:

  • flex-ever-wallet for <ever-wallet-signer>.
  • flex-client for <flex-client-signer>.
  • flex-trader for <flex-trader-signer>.
  • flex-ever-token-wallet for <ever-token-wallet-signer>.
  • flex-tsdt-token-wallet for <tsdt-token-wallet-signer>.


If you have no deployed trader and token wallets yet, you can do it with prepare script.

npm run integration-test-prepare


npm run integration-test

Generated using TypeDoc