Hash-based tracking

This article explains how to find a transaction linked to an external-in message in TON Blockchain. The process involves normalizing the message, searching for the transaction by message hash, and waiting for transaction confirmation.

Hashes

Hashes play a vital role, enabling data identification and verification at all layers of the blockchain. Understanding how hashing works will help you effectively track transactions, validate messages, and integrate your applications with TON.

What is a hash?

In TON, a hash is a cryptographic fingerprint of data based on the SHA-256 algorithm. However, the hashing process is not a direct application of SHA-256 to raw data; it involves serialization and internal formatting steps, and in some cases, may rely on alternative algorithms.

Each cell, message, or transaction has its unique hash, which acts as a digital signature.

Important

Hashes in TON are irreversible — the original data cannot be reconstructed from the hash. However, they are deterministic — the same input always produces the same hash.

TON uses the Merkle–Damgård construction for hashing, a method of building collision-resistant hash functions from one-way compression functions. This design makes it vulnerable to length extension attacks.

warning

If you use hashes for authentication or message integrity, be aware that the Merkle–Damgård construction is susceptible to length extension attacks.

Avoid relying solely on raw hashes in security-critical contexts.

Hashes of structures

Message body hash

The message body hash is a unique identifier of a message’s content. It is calculated from the cell containing the message data.

The body refers to the field body: (Either X ^X):

message$_ {X:Type} info:CommonMsgInfo
  init:(Maybe (Either StateInit ^StateInit))
  body:(Either X ^X) = Message X;

Let’s walk through an example using a message body with the comment "Hello, TON!" and compute its hash.

msg_body_hash.ts
import { beginCell } from "@ton/core";

// Standard body with text comment
const messageBody = beginCell()
  .storeUint(0, 32) // op code
  .storeStringTail("Hello TON!")
  .endCell();

console.log("Message body hash:", messageBody.hash().toString("hex"));

Expected output

Message body hash: d989794fa90c9817a63a22e00554574f3c4a347dcfd2e2886980a294de15f2af

When to use a message body hash:

to verify data integrity
for debugging and logging operations
to deduplicate messages in your application

Full message hash

A full message includes not just the body but also headers with metadata such as the sender, recipient, amount, and fees. Its hash uniquely identifies the entire message.

For internal messages, this corresponds to the Message X structure defined in the following TL-B schema:

message$_ {X:Type} info:CommonMsgInfo
  init:(Maybe (Either StateInit ^StateInit))
  body:(Either X ^X) = Message X;


int_msg_info$0 ihr_disabled:Bool bounce:Bool bounced:Bool
  src:MsgAddressInt dest:MsgAddressInt
  value:CurrencyCollection ihr_fee:Grams fwd_fee:Grams
  created_lt:uint64 created_at:uint32 = CommonMsgInfo;

Example:

full_msg_hash.ts
import { storeMessage, beginCell, Address, Message } from "@ton/ton";
import { toNano } from "@ton/core";

const messageBody = beginCell()
  .storeUint(0, 32) // op code
  .storeStringTail("Hello TON!")
  .endCell();

// Create a complete message object
const message: Message = {
  info: {
    type: "internal",
    dest: Address.parse("UQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAJKZ"), // Insert recipient address
    value: { coins: toNano("0.1") },
    bounce: true,
    src: Address.parse("EQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAM9c"), // Insert sender address
    ihrDisabled: true,
    bounced: false,
    ihrFee: 0n,
    forwardFee: 0n,
    createdAt: 0,
    createdLt: 0n,
  },
  body: messageBody,
};

// Get the complete message hash
const messageCell = beginCell().store(storeMessage(message)).endCell();

const fullMessageHash = messageCell.hash();
console.log("Full message hash:", fullMessageHash.toString("hex"));

Expected output

Full message hash: b213bbaf387106685137f548d4564450295f226fa8a56063854de52ca74a18a1

When to use the complete message hash:

to track specific messages on the blockchain
when using the TON Center API to search for transactions
to verify that no one modified the message

Transaction hash

A transaction hash is a unique identifier for an entire transaction. It derives from all the data involved in the transaction, including incoming and outgoing messages, state changes, and fees. This data becomes available only after the blockchain executes the transaction, so the hash is calculated once the transaction is recorded.

TL-B

The transaction structure is defined in TL-B as follows:

transaction$0111 account_addr:bits256 lt:uint64
    prev_trans_hash:bits256 prev_trans_lt:uint64 now:uint32
    outmsg_cnt:uint15
    orig_status:AccountStatus end_status:AccountStatus
    ^[ in_msg:(Maybe ^(Message Any)) out_msgs:(HashmapE 15 ^(Message Any)) ]
    total_fees:CurrencyCollection state_update:^(HASH_UPDATE Account)
    description:^TransactionDescr = Transaction;

See the full explanation in Transaction layout.

For details on how a hash is computed from the structure above, see:

Cell hash and Standard representation hash calculation on the Cells & BoC page.
The practical section on retrieving hashes in the DApp cookbook.

info

A transaction hash is the representation hash (SHA‑256) of the root Transaction cell serialized per TL‑B, precisely as it appears in the block. Any change to messages, fees, or the state update alters the hash.

Obtaining a transaction hash:

trx_hash.ts
import { TonClient, beginCell, storeMessage } from "@ton/ton";
import { Address } from "@ton/core";

async function main() {
  const client = new TonClient({
    // Testnet endpoint; if you're working on Mainnet, don't forget to update this
    endpoint: "https://testnet.toncenter.com/api/v2/jsonRPC",
    // apiKey: 'insert your api key', // Get your API key via the @toncenter bot
  });

  const transactions = await client.getTransactions(
    Address.parse("kQCZJvXJRBQCBgXKtMvdV7ivumeLylPNTjcrtDLX5zIlvigu"), // Insert your wallet address here
    { archival: true, limit: 10 }
  );

  for (const tx of transactions) {
    const txHash = tx.hash();
    console.log("Transaction hash:", txHash.toString("hex"));

    // You can also get the hash of the incoming message
    if (tx.inMessage) {
      const inMsgCell = beginCell().store(storeMessage(tx.inMessage)).endCell();
      const inMsgHash = inMsgCell.hash();
      console.log("Incoming message hash:", inMsgHash.toString("hex"));
    }
  }
}

main().catch(console.error);

Expected output

Displays the last 10 transactions for the specified address. For each transaction, it prints the transaction hash. If an incoming message exists, it also prints the hash of that message.

Transaction hash: bd96d252e77b9ba31c5a9eccab9d184fa3dbf566358708ece2d522a1a6e2d9ea
Incoming message hash: 62810591b9dd72b674b8892f6ba543863923095c23d41e5ea009c47488754a6d
Transaction hash: 4f60a63291592119990faeabd463201a157a9a0976cb30996caa3c6d593c8791
Incoming message hash: d9b55fecc7a7cbb34ba98cd1a7749f00d4d41aa11f7a8705a6f6759311791a4e

Normalized message hash

Normalization is a standardization process that converts different representations into a consistent format. While messages across interfaces follow the TL-B scheme, structural differences in implementation sometimes lead to collisions.

To address this, the ecosystem defines a standard that ensures consistent hash calculation. The normalization rules are specified in detail in TEP-467.

The problem normalization solves:

Functionally identical messages may differ in how they represent the src, import_fee, and init fields. These variations result in different hashes for messages with equivalent content, which complicates transaction tracking and deduplication.

How normalization works:

The normalized hash is computed by applying the following standardization rules to an external-in message:

Source Address (src): set to addr_none$00
Import Fee (import_fee): set to 0
InitState (init): set to an empty value
Body: always stored as a reference

Practical example of calculating a normalized hash:

norm_hash.ts
import { beginCell, Cell, Address } from "@ton/core";

function normalizeExternalMessage(destAddress: Address, bodyCell: Cell): Cell {
  try {
    const normalizedExtMessage = beginCell()
      .storeUint(0b10, 2) // Set external message prefix (10 in binary)
      .storeUint(0, 2) // Set src to addr_none (normalization)
      .storeAddress(destAddress) // Set destination address
      .storeCoins(0) // Set import_fee to 0 (normalization)
      .storeBit(false) // Set init to nothing$0 (normalization)
      .storeBit(true) // Use right$1 to store body by reference (normalization)
      .storeRef(bodyCell) // Store body as a reference (normalization)
      .endCell();

    return normalizedExtMessage;
  } catch (error: any) {
    console.error("Error in normalization:", error.message);
    throw error;
  }
}

const messageBody = beginCell()
  .storeUint(0, 32) // Set opcode for a simple transfer
  .storeStringTail("Normalized hash example")
  .endCell();

const destinationAddress = Address.parse(
  "EQDequZRihH9JMHanFOtOK7dNfSmbRvvTx4wgUctknapINd9"
);
const normalizedExternalMessage = normalizeExternalMessage(
  destinationAddress,
  messageBody
);
const normalizedHash = normalizedExternalMessage.hash().toString("hex");

console.log("Normalized message hash:", normalizedHash);

Expected output

Normalized message hash: ce70ed4db0fd40aee2bd62b7d92707e8860762737872245687cc2381954cae20

info

This example shows a low-level construction of the message. For a higher-level, SDK-based approach, see the example in TON Connect.

Practical example of calculating a non-normalized hash:

Before April 2025, message hashes were not normalized across the ecosystem. If your code constructs messages without applying normalization, it may produce inconsistent hashes. In such cases, update the logic to follow the normalization rules described in TEP-467.

Below is an example of non-normalized message construction — avoid using this approach:

Avoid this approach

non_norm_hash.ts
import { mnemonicToWalletKey } from "@ton/crypto";
import {
  WalletContractV4,
  TonClient,
  toNano,
  beginCell,
  Address,
  internal,
} from "@ton/ton";

// Create a client instance for accessing Testnet via TON Center
const client = new TonClient({
  endpoint: "https://testnet.toncenter.com/api/v2/jsonRPC",
  apiKey: "your api key", // Get your API key via the toncenter.com bot
});

// Construct the message body — arbitrary opcode and payload string
const messageBody = beginCell()
  .storeUint(0, 32) // op-code — arbitrary, e.g., 0
  .storeStringTail("Hello TON!") // Payload string in the message body
  .endCell();

// Wrap the body into an internal message
const internalMessage = internal({
  to: Address.parse("0QD3...."), // recipient
  value: toNano("0.1"), // 0.1 TON
  body: messageBody,
});

async function main() {
  // Derive wallet keys from the mnemonic phrase
  const mnemonic = "your seed phrase"; // Insert your seed phrase here
  const keyPair = await mnemonicToWalletKey(mnemonic.split(" "));

  // Create a WalletContractV4 instance from the public key
  const wallet = WalletContractV4.create({
    publicKey: keyPair.publicKey,
    workchain: 0,
  });

  const contract = client.open(wallet);
  const seqno = await contract.getSeqno();

  // Create an external message using the wallet contract
  const externalMessage = await wallet.createTransfer({
    seqno,
    secretKey: keyPair.secretKey,
    messages: [internalMessage],
  });

  console.log(
    "Non-normalized external message hash:",
    externalMessage.hash().toString("hex")
  );
}

main();

The algorithm may differ from the normalized version in any way. If the absence of normalization causes issues in an existing project, the correct approach is to migrate to normalized hashes across the entire codebase.

Hashes for backend validation

One common scenario is sending a message and checking that the blockchain accepts and processes it.

This example shows how to send a message and verify that it was processed.

send_and_verify_msg.ts
import { mnemonicToPrivateKey } from "@ton/crypto";
import {
  TonClient,
  WalletContractV5R1,
  internal,
  SendMode,
  beginCell,
  storeMessage,
  Message,
  Transaction,
  loadMessage,
  Cell,
} from "@ton/ton";

export function getNormalizedExtMessageHash(message: Message) {
  if (message.info.type !== "external-in") {
    throw new Error(`Message must be "external-in", got ${message.info.type}`);
  }
  const info = {
    ...message.info,
    src: undefined,
    importFee: 0n,
  };
  const normalizedMessage = {
    ...message,
    init: null,
    info: info,
  };
  return beginCell()
    .store(storeMessage(normalizedMessage, { forceRef: true }))
    .endCell()
    .hash();
}

// Modified version of the retry function from the TON Connect example
async function retry<T>(
  fn: () => Promise<T>,
  options: {
    retries: number;
    delay: number;
    progress?: boolean;
    progressLabel?: string;
  }
): Promise<T> {
  let lastError: Error | undefined;
  let printedHeader = false;
  let printedAnything = false;
  for (let i = 0; i < options.retries; i++) {
    if (options.progress) {
      if (!printedHeader && options.progressLabel) {
        process.stdout.write(`${options.progressLabel}: `);
        printedHeader = true;
      }
      process.stdout.write(".");
      printedAnything = true;
    }
    try {
      const result = await fn();
      if (printedAnything) process.stdout.write("\n");
      return result;
    } catch (e) {
      if (e instanceof Error) lastError = e;
      if (i < options.retries - 1) {
        await new Promise((resolve) => setTimeout(resolve, options.delay));
      }
    }
  }
  if (printedAnything) process.stdout.write("\n");
  throw lastError;
}

async function getTransactionByInMessage(
  inMessageBoc: string,
  client: TonClient
): Promise<Transaction | undefined> {
  const inMessage = loadMessage(Cell.fromBase64(inMessageBoc).beginParse());
  if (inMessage.info.type !== "external-in") {
    throw new Error(
      `Message must be "external-in", got ${inMessage.info.type}`
    );
  }
  const account = inMessage.info.dest;
  const targetInMessageHash = getNormalizedExtMessageHash(inMessage);
  let lt: string | undefined = undefined;
  let hash: string | undefined = undefined;
  while (true) {
    const transactions = await retry(
      () =>
        client.getTransactions(account, {
          hash,
          lt,
          limit: 10,
          archival: true,
        }),
      { delay: 1000, retries: 3 }
    );
    if (transactions.length === 0) {
      return undefined;
    }
    for (const transaction of transactions) {
      if (transaction.inMessage?.info.type !== "external-in") {
        continue;
      }
      const inMessageHash = getNormalizedExtMessageHash(transaction.inMessage);
      if (inMessageHash.equals(targetInMessageHash)) {
        return transaction;
      }
    }
    const last = transactions.at(-1)!;
    lt = last.lt.toString();
    hash = last.hash().toString("base64");
  }
}

async function sendAndVerifyMessage() {
  // Client configuration
  // - Testnet:      endpoint = https://testnet.toncenter.com/api/v2/jsonRPC
  // - Mainnet:      endpoint = https://toncenter.com/api/v2/jsonRPC
  // Note: Many providers require an API key on both networks. Replace with your key.
  const client = new TonClient({
    endpoint: "https://testnet.toncenter.com/api/v2/jsonRPC",
    apiKey: "your api key", // Get your API key via @toncenter bot
  });

  // Load wallet key pair from mnemonic
  const mnemonic = "your seed phrase".split(" "); // Insert your seed phrase here
  const keyPair = await mnemonicToPrivateKey(mnemonic);

  // Wallet selection
  // - V5R1 on Testnet:    walletId.networkGlobalId = -3   (must be set)
  // - V5R1 on Mainnet:    walletId.networkGlobalId = -239 (default value)
  // - V4/V3R2 on either:  no walletId field, only { workchain, publicKey }
  const walletContract = WalletContractV5R1.create({
    publicKey: keyPair.publicKey,
    workchain: 0,
    //walletId: { networkGlobalId: -3 }, // testnet
  });

  const wallet = client.open(walletContract);

  // Log on-chain state to be sure that the wallet has funds to send a message
  console.log(
    "Wallet address (bounceable):    ",
    wallet.address.toString({ testOnly: false, bounceable: true })
  );
  console.log(
    "Wallet address (non-bounceable):",
    wallet.address.toString({ testOnly: false, bounceable: false })
  );

  const onchainState = await retry(
    () => client.getContractState(wallet.address),
    {
      retries: 2,
      delay: 2000,
      progress: true,
      progressLabel: "getContractState",
    }
  );
  const isDeployed = onchainState.state === "active";
  console.log("Is deployed:", isDeployed);
  console.log("On-chain state:", onchainState.state);
  console.log("Balance:", onchainState.balance.toString());
  console.log("Last tx:", onchainState.lastTransaction);

  // Create message body with comment
  const messageBody = beginCell()
    .storeUint(0, 32)
    .storeStringTail("Hello TON!")
    .endCell();

  // Get current seqno
  const seqno = await retry(() => wallet.getSeqno(), {
    retries: 2,
    delay: 2000,
    progress: true,
    progressLabel: "getSeqno",
  });

  const timeoutSec = Math.floor(Date.now() / 1e3) + 300; // fixed timeout to keep hashes stable

  const transferArgs = {
    secretKey: keyPair.secretKey,
    seqno,
    messages: [
      internal({
        to: wallet.address, // Your wallet address
        value: "0.05",
        body: messageBody,
      }),
    ],
    timeout: timeoutSec,
    sendMode: SendMode.PAY_GAS_SEPARATELY + SendMode.IGNORE_ERRORS,
  };

  const transfer = await wallet.createTransfer(transferArgs);

  // Build external-in message
  const message: Message = {
    info: {
      type: "external-in",
      src: null,
      dest: wallet.address,
      importFee: 0n,
    },
    init: null,
    body: transfer,
  };

  // Build a cell with the external-in message
  const externalMessageCell = beginCell()
    .store(storeMessage(message, { forceRef: true }))
    .endCell();

  // Calculate hashes if you need to store them, prefer normalized hash
  const fullHash = externalMessageCell.hash();
  const normalizedHash = getNormalizedExtMessageHash(message);
  console.log("Full message hash:      ", fullHash.toString("hex"));
  console.log("Normalized message hash:", normalizedHash.toString("hex"));

  // Send using wallet.sendTransfer so StateInit is attached automatically if needed
  await retry(() => wallet.sendTransfer(transferArgs), {
    retries: 6,
    delay: 1500,
    progress: true,
    progressLabel: "sendExternalMessage",
  });

  // Wait until seqno increases, otherwise stop with an error
  await retry(
    async () => {
      const current = await wallet.getSeqno();
      if (current <= seqno) throw new Error("Seqno not increased yet");
      return current;
    },
    { retries: 60, delay: 1500, progress: true, progressLabel: "waitSeqno" }
  );

  // Wait until the transaction with matching normalized incoming message appears
  const tx = await retry(
    async () => {
      const found = await getTransactionByInMessage(
        externalMessageCell.toBoc().toString("base64"),
        client
      );
      if (!found) throw new Error("Tx not found yet");
      return found;
    },
    { retries: 60, delay: 1500, progress: true, progressLabel: "findTx" }
  );
  if (!tx) {
    console.log("Transaction was not found");
    return;
  }
  const txHashHex = tx.hash().toString("hex");
  console.log("Transaction found:", txHashHex);
  // Explorer link:
  // - Testnet: https://testnet.tonviewer.com/transaction/<hash>
  // - Mainnet: https://tonviewer.com/transaction/<hash>
  console.log(
    "Transaction link: ",
    `https://tonviewer.com/transaction/${txHashHex}`
  );
}

sendAndVerifyMessage().catch(console.error);

Expected output

Example output
  Wallet address (bounceable):    EQDJLX-tXmU4Aj6kdWWd07HJfd8xqOyXwqh-RVaPkBrcyu_K
  Wallet address (non-bounceable): UQDJLX-tXmU4Aj6kdWWd07HJfd8xqOyXwqh-RVaPkBrcyrIP
  getContractState: .
  Is deployed: true
  On-chain state: active
  Balance: 3151372144
  Last tx: {
  lt: '60465817000003',
  hash: 'Tnddfj2PJcfAmRT8Z46larmzg2L8WlCaj0cdvcye5so='
  }
  getSeqno: .
  Full message hash:       bc5c47b0d23f41ccd60f9c363c37c9110fedbba417cb396c9058130e48ac2289
  Normalized message hash: bc5c47b0d23f41ccd60f9c363c37c9110fedbba417cb396c9058130e48ac2289
  sendExternalMessage: .
  waitSeqno: .......
  findTx: .
  Transaction found: a73ff82f9b09f722eade22ea39640434e04b6dbc9266040fd8467e080f5efb2e
  Transaction link:  https://tonviewer.com/transaction/a73ff82f9b09f722eade22ea39640434e04b6dbc9266040fd8467e080f5efb2e

Hashes for frontend validation

Data representation in TON

All data in TON is stored in cells. Conceptually, a cell is a structure that holds up to 1023 bits of data and up to 4 references to other cells. Cell trees are serialized and packed using a unified standard cell format.

In TL-B, this structure is referred to as a bag of cells (BoC):

serialized_boc#b5ee9c72 has_idx:(## 1) has_crc32c:(## 1)
  has_cache_bits:(## 1) flags:(## 2) { flags = 0 }
  size:(## 3) { size <= 4 }
  off_bytes:(## 8) { off_bytes <= 8 }
  cells:(##(size * 8))
  roots:(##(size * 8)) { roots >= 1 }
  absent:(##(size * 8)) { roots + absent <= cells }
  tot_cells_size:(##(off_bytes * 8))
  root_list:(roots * ##(size * 8))
  index:has_idx?(cells * ##(off_bytes * 8))
  cell_data:(tot_cells_size * [ uint8 ])
  crc32c:has_crc32c?uint32
  = BagOfCells;

A deep understanding of this structure isn’t required — TON development tools and SDKs already include helpers that handle it for you.

Transaction lookup using BoC

When a user confirms the sending of an external message via TON Connect, you receive a BoC or bag of cells. You can use this BoC to look up the corresponding transaction on the blockchain.

Usage example:

Let’s walk through an example of sending an external message using TON Connect in a React app. We use the demo-dapp-with-react-ui project as a reference to obtain the BoC and hash to find a transaction.

In this project, navigate to src/components/TxForm and replace the contents of the TxForm.tsx react file with the following code:

Obtaining BoC and hash using react example

TxForm.tsx
import React, { useState } from "react";
import "./style.scss";
import { SendTransactionRequest, useTonConnectUI } from "@tonconnect/ui-react";
import {
  Address,
  beginCell,
  Cell,
  loadMessage,
  Message,
  storeMessage,
  loadStateInit,
  contractAddress,
} from "@ton/ton";

// This example uses a predefined smart contract `stateInit` of an EchoContract —
// a contract that returns the sent value back to the sender. The destination
// address is derived from the provided stateInit to avoid mismatches.
const echoStateInitBocBase64 =
  "te6cckEBBAEAOgACATQCAQAAART/APSkE/S88sgLAwBI0wHQ0wMBcbCRW+D6QDBwgBDIywVYzxYh+gLLagHPFsmAQPsAlxCarA==";
const echoStateInit = loadStateInit(
  Cell.fromBase64(echoStateInitBocBase64).beginParse()
);
const echoContractAddress = contractAddress(0, echoStateInit).toString({
  testOnly: true,
  urlSafe: true,
  bounceable: false,
});
const defaultTx: SendTransactionRequest = {
  // The transaction is valid for 10 minutes from the current time (in Unix epoch seconds).
  validUntil: Math.floor(Date.now() / 1000) + 600,
  messages: [
    {
      // Destination is derived from the provided stateInit (EchoContract).
      address: echoContractAddress,
      // Amount to send in nanoTON. 0.005 TON is 5000000 nanoTON.
      amount: "5000000",
      // State initialization in BOC (base64) for contract deployment.
      stateInit: echoStateInitBocBase64,
    },
  ],
};

export function getNormalizedExtMessageHash(message: Message) {
  if (message.info.type !== "external-in") {
    throw new Error(`Message must be "external-in", got ${message.info.type}`);
  }
  const info = {
    ...message.info,
    src: undefined,
    importFee: 0n,
  };
  const normalizedMessage = {
    ...message,
    init: null,
    info: info,
  };
  return beginCell()
    .store(storeMessage(normalizedMessage, { forceRef: true }))
    .endCell()
    .hash();
}

// Helper function to get normalized hash from BOC
export function normalizedExtHashFromBoc(bocBase64: string): string {
  const msg = loadMessage(Cell.fromBase64(bocBase64).beginParse());
  return getNormalizedExtMessageHash(msg).toString("hex");
}

export function TxForm() {
  const [boc, setBoc] = useState<string | null>(null);
  const [hash, setHash] = useState<string | null>(null);
  const [normalizedHash, setNormalizedHash] = useState<string | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [isSending, setIsSending] = useState(false);
  const [tonConnectUi] = useTonConnectUI();

  const send = async () => {
    setIsSending(true);
    setError(null);
    setBoc(null);
    setHash(null);
    setNormalizedHash(null);
    try {
      const result = await tonConnectUi.sendTransaction(defaultTx);
      const receivedBoc = result.boc;
      setBoc(receivedBoc);
      const externalMessageCell = Cell.fromBoc(
        Buffer.from(receivedBoc, "base64")
      )[0];
      const originalHash = externalMessageCell.hash().toString("hex");
      setHash(originalHash);
      const normalizedHash = normalizedExtHashFromBoc(receivedBoc);
      setNormalizedHash(normalizedHash);

      const message = loadMessage(externalMessageCell.beginParse());
      if (message.info.type !== "external-in")
        throw new Error(
          `Expected an external-in message, got ${message.info.type}.`
        );

      const destAddress = message.info.dest;
      if (!destAddress || !(destAddress instanceof Address)) {
        throw new Error("Destination address not found in the parsed message.");
      }
    } catch (e) {
      setError((e as Error).message);
    } finally {
      setIsSending(false);
    }
  };

  return (
    <div className="send-tx-form" style={{ color: "#ffffff" }}>
      <button onClick={send} disabled={isSending}>
        {isSending ? "Sending..." : "Send transaction"}
      </button>

      {error && <p style={{ color: "red" }}>Error: {error}</p>}

      {boc && (
        <div className="boc-hash-block" style={{ color: "#ffffff" }}>
          <span className="boc-label">BOC (base64):</span>
          <pre className="boc-pre">{boc}</pre>

          <span className="hash-label">
            Original hash to find a transaction:
          </span>
          <pre>{hash}</pre>

          <span className="hash-label">Normalized hash (TEP-467):</span>
          <pre>{normalizedHash}</pre>

          {hash && normalizedHash && (
            <div
              style={{
                marginTop: "10px",
                padding: "10px",
                backgroundColor:
                  hash === normalizedHash ? "#d4edda" : "#f8d7da",
                borderRadius: "5px",
                color: "#0F0F0F",
              }}
            >
              <strong>
                Hashes {hash === normalizedHash ? "MATCH" : "DO NOT MATCH"}
              </strong>
              {hash !== normalizedHash && (
                <div style={{ fontSize: "12px", marginTop: "5px" }}>
                  The original message is not normalized according to TEP-467.
                </div>
              )}
            </div>
          )}
        </div>
      )}
    </div>
  );
}

After you run the code via npm run dev, the demo DApp launches. To proceed:

Connect your Tonkeeper wallet.
Click the Send transaction button.
Approve the transaction in your wallet.

Once the transaction is sent, the UI displays the following fields:

BOC (base64) – the raw external message in base64 format.
Original hash – the hash of the message as sent. You can use it to look up the transaction on-chain.
Normalized hash (TEP-467) – the hash computed after normalization, used for consistent message identification.

To find a transaction by its BoC (base64), refer to the getTransactionByInMessage function in the backend validation example.

Transaction status check using hash

status_api.ts
// Check the transaction status by its hash
async function checkTransactionStatus(txHash: string, walletAddress: string) {
  try {
    const response = await fetch(
      `https://testnet.toncenter.com/api/v2/getTransactions?` +
        `address=${walletAddress}&hash=${txHash}`
    );
    const data = await response.json();

    if (data.result.length > 0) {
      console.log("Transaction found on the blockchain");
      const viewerUrl = `https://testnet.tonviewer.com/transaction/${trxHash}`;
      console.log("Transaction link:", viewerUrl);
      return data.result[0];
    } else {
      console.log("Transaction not found");
      return null;
    }
  } catch (error) {
    console.error("Error while checking transaction status:", error);
    return null;
  }
}

const walletAddress = "your address";
const trxHash = "your trx hash";

checkTransactionStatus(trxHash, walletAddress);

Expected output

Transaction found on the blockchain
Transaction link: https://testnet.tonviewer.com/transaction/df51860233d75...

StateInit hash for address validation

In TON Connect, you often need to verify that a wallet address corresponds to its StateInit. The StateInit hash must match the hash portion of the address.

Practical example of address verification:

Address verification example with generated StateInit

get_stateinit.ts
import {
  WalletContractV5R1,
  beginCell,
  Address,
  Cell,
  contractAddress,
} from "@ton/ton";
import { mnemonicToPrivateKey } from "@ton/crypto";

async function getStateInit(
  mnemonic: string[]
): Promise<{ stateInitBase64: string; walletAddress: Address }> {
  const keyPair = await mnemonicToPrivateKey(mnemonic);

  // Create a wallet V5R1 (for mainnet omit walletId or set -239; for testnet set -3)
  const wallet = WalletContractV5R1.create({
    publicKey: keyPair.publicKey,
    workchain: 0,
    //walletId: { networkGlobalId: -3 }, // testnet
  });

  // Generate the StateInit cell (code + data)
  const stateInitCell = beginCell()
    .storeRef(wallet.init.code)
    .storeRef(wallet.init.data)
    .endCell();

  const stateInitBase64 = stateInitCell.toBoc().toString("base64");

  console.log("StateInit (base64):", stateInitBase64);
  console.log("StateInit (hash):  ", stateInitCell.hash().toString("base64"));
  console.log(
    "Wallet address:    ",
    wallet.address.toString({ bounceable: true })
  );
  console.log(
    "Public key (hex):  ",
    Buffer.from(keyPair.publicKey).toString("hex")
  );

  return { stateInitBase64, walletAddress: wallet.address };
}

function validateStateInitMatchesAddress(
  wantedAddress: Address,
  stateInitBase64: string
) {
  const cell = Cell.fromBase64(stateInitBase64);
  // Typically: code = refs[0], data = refs[1]
  const stateInit = {
    code: cell.refs[0],
    data: cell.refs[1],
  };

  // Derive address from workchain + StateInit
  const calculatedAddress = contractAddress(wantedAddress.workChain, stateInit);

  console.log(
    "Expected address:  ",
    wantedAddress.toString({ bounceable: true })
  );
  console.log(
    "Calculated address:",
    calculatedAddress.toString({ bounceable: true })
  );

  if (calculatedAddress.equals(wantedAddress)) {
    console.log("StateInit matches the address!");
  } else {
    console.log("StateInit does NOT match the address!");
  }
}

async function main() {
  // Example: derive StateInit from mnemonic and validate against the derived address
  // We pass address to the function to extract workchain and then compare with calculated address
  const mnemonic = "your mnemonic".split(" "); // Insert your seed phrase here
  const { stateInitBase64, walletAddress } = await getStateInit(mnemonic);
  validateStateInitMatchesAddress(walletAddress, stateInitBase64);

  // Example: you can get state from api/explorer in base64 format
/*  
  const stateInit = new StateInit({
        code: Cell.fromBoc(
          Buffer.from(accountDetails.state.code!, "base64")
        )[0],
        data: Cell.fromBoc(
          Buffer.from(accountDetails.state.data!, "base64")
        )[0],
      });
*/
}

main().catch(console.error);

Transaction lookup by message hash

The example below shows how to set up a listener that receives transaction data as soon as it becomes available.

Code

trxs_monitoring.ts
import { Address, TonClient, beginCell, storeMessage } from "@ton/ton";

// Example function to monitor incoming transactions
async function monitorIncomingTransactions(
  walletAddress: Address,
  client: TonClient
) {
  let lastLt = 0n;

  setInterval(async () => {
    try {
      const transactions = await client.getTransactions(walletAddress, {
        limit: 10,
        lt: lastLt.toString(),
      });

      for (const tx of transactions) {
        if (tx.lt > lastLt) {
          const txHash = tx.hash();
          console.log("New transaction:", txHash.toString("hex"));
          const viewerUrl = `https://testnet.tonviewer.com/transaction/${txHash.toString("hex")}`;
          console.log("Transaction link:", viewerUrl);

          // Process incoming messages
          if (tx.inMessage) {
            const msgCell = beginCell()
              .store(storeMessage(tx.inMessage))
              .endCell();
            const msgHash = msgCell.hash();
            console.log("Message hash:", msgHash.toString("hex"));
          }

          lastLt = tx.lt;
        }
      }
    } catch (error) {
      console.error("Monitoring error:", error);
    }
  }, 5000); // Check every 5 seconds
}

const walletAddress = Address.parse("Insert your address here");
const client = new TonClient({
  endpoint: "https://testnet.toncenter.com/api/v2/jsonRPC",
});

monitorIncomingTransactions(walletAddress, client);

Expected output

New transaction: 2e995e47f47bb95f1802337f4a63841b93aa8972aabba545048ef286dcc14309
Transaction link: https://testnet.tonviewer.com/transaction/2e995e47f47bb95f1802337f4a63841b93aa8972aabba545048ef286dcc14309
Message hash: 8263a63380532154a3850aa1d2dca719bf768845738c8177d889af05826626c8

Next step

We covered how every message and transaction in TON is assigned a unique cryptographic fingerprint — a hash. These hashes enable us to verify content, detect duplicates, and track the entire execution flow across the blockchain.

Now, let’s explore how to retrieve and analyze transactions using the API — turning hashes into actionable data.

Process transactions with the API

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Hashes​

What is a hash?​

Hashes of structures​

Message body hash​

Expected output​

Full message hash​

Example:​

Expected output​

Transaction hash​

TL-B​

Expected output​

Normalized message hash​

Expected output​

Hashes for backend validation​

Expected output​

Hashes for frontend validation​

Data representation in TON​

Transaction lookup using BoC​

Transaction status check using hash​

Expected output​

StateInit hash for address validation​

Transaction lookup by message hash​

Next step​

Hashes

What is a hash?

Hashes of structures

Message body hash

Expected output

Full message hash

Example:

Expected output

Transaction hash

TL-B

Expected output

Normalized message hash

Expected output

Hashes for backend validation

Expected output

Hashes for frontend validation

Data representation in TON

Transaction lookup using BoC

Transaction status check using hash

Expected output

StateInit hash for address validation

Transaction lookup by message hash

Next step