TON Connect for Python

The recommended SDK for Python applications is tonutils. It is a Python library that provides a high-level interface for interacting with the TON blockchain, including TON Connect.

Implementation

Installation

pip install tonutils

To store user wallet connection data, you need to implement a storage interface. An additional dependency is required for this. In this example, a file-based implementation using aiofiles is used:

pip install aiofiles

Creating the Manifest

Create the manifest.json file for your application according to the guidelines, and host it at a publicly accessible URL.

Implementing Storage

To store connection data with user wallets, a storage interface must be implemented.

Example implementation

import json
import os
from asyncio import Lock
from typing import Dict, Optional

import aiofiles

from tonutils.tonconnect import IStorage


class FileStorage(IStorage):

    def __init__(self, file_path: str):
        self.file_path = file_path
        self.lock = Lock()

        if not os.path.exists(self.file_path):
            with open(self.file_path, "w") as f:
                json.dump({}, f)  # type: ignore

    async def _read_data(self) -> Dict[str, str]:
        async with self.lock:
            async with aiofiles.open(self.file_path, "r") as f:
                content = await f.read()
                if content:
                    return json.loads(content)
                return {}

    async def _write_data(self, data: Dict[str, str]) -> None:
        async with self.lock:
            async with aiofiles.open(self.file_path, "w") as f:
                await f.write(json.dumps(data, indent=4))

    async def set_item(self, key: str, value: str) -> None:
        data = await self._read_data()
        data[key] = value
        await self._write_data(data)

    async def get_item(self, key: str, default_value: Optional[str] = None) -> Optional[str]:
        data = await self._read_data()
        return data.get(key, default_value)

    async def remove_item(self, key: str) -> None:
        data = await self._read_data()
        if key in data:
            del data[key]
            await self._write_data(data)

Initializing TON Connect

Create a TonConnect instance by specifying the manifest URL and the storage object:

from storage import FileStorage
from tonutils.tonconnect import TonConnect

TC_MANIFEST_URL = "https://raw.githubusercontent.com/nessshon/tonutils/main/examples/tonconnect/tonconnect-manifest.json"
TC_STORAGE = FileStorage("connection.json")

tc = TonConnect(
    storage=TC_STORAGE,
    manifest_url=TC_MANIFEST_URL,
    wallets_fallback_file_path="./wallets.json"
)

The wallets_fallback_file_path parameter is used as a fallback source of wallet data (e.g., Tonkeeper, Wallet) in case the external API is unavailable. You can find all input parameters at the following link.

Initializing the Connector

Create a Connector instance to work with a specific user:

connector = await tc.init_connector(user_id)

• user_id can be an integer (int) or a string (str).

• If not provided, an incremental ID will be assigned automatically.

• You can store the user ID for future reference:

  user_id = connector.user_id

Connecting a Wallet

Retrieving the List of Wallets

To display available wallets in the user interface, retrieve the list of supported wallets:

wallets = await tc.get_wallets()

You can then display the list using each wallet’s name via wallet.name.

Connecting to a Wallet

After the user selects a wallet from the list, initiate the connection (for example, selecting the wallet at index 1):

selected_wallet = wallets[1]
connect_url = await connector.connect_wallet(selected_wallet)

You should present the connect_url to the user in your application.

With Redirect URL

If you want to automatically redirect the user after a successful connection, pass the redirect_url parameter:

redirect_url = "https://example.com/"
connect_url = await connector.connect_wallet(selected_wallet, redirect_url=redirect_url)

With TON Proof

To ensure that the user truly owns the specified address, you can enable address ownership verification using ton_proof. Generate the proof payload and pass it via the ton_proof parameter. More details on this mechanism and payload generation are available here.

You can also use the built-in generate_proof_payload function from tonutils:

from tonutils.tonconnect.utils import generate_proof_payload

redirect_url = "https://example.com/"
proof_payload = generate_proof_payload()
connect_url = await connector.connect_wallet(
    selected_wallet,
    redirect_url=redirect_url,
    ton_proof=proof_payload
)

Handling the Connection

To handle the result of a wallet connection, use the connect_wallet_context context manager.

Example using the context manager:

from tonutils.tonconnect.utils.exceptions import TonConnectError, UserRejectsError

async with connector.connect_wallet_context() as response:
    if isinstance(response, TonConnectError):
        if isinstance(response, UserRejectsError):
            print("The user rejected the connection.")
        else:
            print(f"Connection error: {response.message}")
    else:
        print(f"Connected wallet: {response.account.address.to_str(is_bounceable=False)}")

Example with ton_proof verification:

from tonutils.tonconnect.utils.exceptions import TonConnectError, UserRejectsError

async with connector.connect_wallet_context() as response:
    if isinstance(response, TonConnectError):
        if isinstance(response, UserRejectsError):
            print("The user rejected the connection.")
        else:
            print(f"Connection error: {response.message}")
    else:
        if connector.wallet.verify_proof_payload(proof_payload):
            print(f"Connected wallet: {response.account.address.to_str(is_bounceable=False)}")
        else:
            await connector.disconnect_wallet()
            print("Proof verification failed.")

The context manager will pause execution until:

• the user connects a wallet;
• a timeout occurs;
• or an error is raised.

On success, you will receive a WalletInfo object containing the connected wallet's data. On failure, a TonConnectError instance will be returned, which you can handle as described in the connection errors section.

Sending Requests

Sending a Transaction

To send Toncoin to a specific address, use the send_transaction method:

from tonutils.tonconnect.models import Transaction, Message

rpc_request_id = await connector.send_transaction(
    transaction=Transaction(
        valid_until=int(time.time() + 5 * 60),
        messages=[
            Message(
                address="UQCZq3_Vd21-4y4m7Wc-ej9NFOhh_qvdfAkAYAOHoQ__Ness",
                amount=str(int(1 * 1e9)),
            )
        ]
    )
)

• valid_until – transaction expiration time in seconds
• address – recipient in user-friendly format
• amount – amount in nanotons

The method returns rpc_request_id, a unique identifier for tracking the request.

Sending a Simplified Transfer

The tonutils library also provides higher-level methods for sending transactions more conveniently.

• The valid_until field is set to 5 minutes by default.

• The address field is replaced with destination (a string or an Address).

• The amount should be specified in TON instead of nanotons.

• The body parameter can be one of the following:

  • a Cell object — for passing a custom payload;
  • a string — used as a comment or memo;

Single Transfer

rpc_request_id = await connector.send_transfer(
    destination="UQCZq3_Vd21-4y4m7Wc-ej9NFOhh_qvdfAkAYAOHoQ__Ness",
    amount=1,
    body="Hello from tonutils!",
)

Batch Transfer

Before sending multiple messages in one transaction, ensure the wallet supports the required number of messages:

max_messages = connector.device.get_max_supported_messages(connector.wallet)

The maximum number of messages supported in a single transaction depends on the wallet version. Use this limit to shape your transaction logic appropriately.

from tonutils.tonconnect.models.transfer import TransferMessage

rpc_request_id = await connector.send_batch_transfer(
    messages=[
        TransferMessage(
            destination="UQCZq3_Vd21-4y4m7Wc-ej9NFOhh_qvdfAkAYAOHoQ__Ness",
            amount=1,
            body="Hello from tonutils!",
        ),
        TransferMessage(
            destination="UQCZq3_Vd21-4y4m7Wc-ej9NFOhh_qvdfAkAYAOHoQ__Ness",
            amount=2,
            body="Hello from tonutils!",
        ),
    ]
)

These methods also return an rpc_request_id.

Sending a Sign Data Request

The sign_data method allows requesting a cryptographic signature from the user’s wallet for arbitrary content. This signature confirms explicit consent and can be verified off-chain or passed into a smart contract.

TON Connect supports three data formats:

Text

Use when the content is human-readable.

• Clear to the user.
• Ideal for off-chain confirmations.

from tonutils.tonconnect.models import SignDataPayloadText

text = "I confirm deletion of my account and all associated data."
payload = SignDataPayloadText(text=text)

Binary

Use for hashes, files, or non-readable content.

• Suitable for digital receipts, proofs, or opaque payloads.

from tonutils.tonconnect.models import SignDataPayloadBinary

data = "I confirm deletion of my account and all associated data.".encode("utf-8")
payload = SignDataPayloadBinary(bytes=data)

Cell

Use when the signature must be verifiable on-chain.

• Supports TL-B schemas.
• Enables smart contract validation.

from pytoniq_core import begin_cell
from tonutils.tonconnect.models import SignDataPayloadCell

comment = "I confirm deletion of my account and all associated data."
cell = begin_cell().store_uint(0, 32).store_snake_string(comment).end_cell()
schema = "text_comment#00000000 text:Snakedata = InMsgBody;"

payload = SignDataPayloadCell(cell=cell, schema=schema)

The last type in the provided TL-B schema is used as the root type for serialization.

Sending the Request

Before sending the request, you must ensure that the connected wallet supports the sign data feature. Use the following check:

connector.device.verify_sign_data_feature(connector.wallet, payload)

If the feature is not supported, a WalletNotSupportFeatureError will be raised. You can handle it like this:

from tonutils.tonconnect.utils.exceptions import WalletNotSupportFeatureError

try:
    connector.device.verify_sign_data_feature(connector.wallet, payload)
except WalletNotSupportFeatureError:
    print("Wallet does not support sign data feature!")
    # Handle fallback logic or abort

If the feature is supported, proceed to send the request:

rpc_request_id = await connector.sign_data(payload)

Handling Request Results

Use the pending_request_context context manager to wait for a user’s response to both transaction and signing requests.

The context manager pauses execution until:

• the user takes action in their wallet;
• a timeout occurs;
• or an error is raised.

On success, it returns a response object specific to the request type:

• SendTransactionResponse
• SignDataResponse

On failure, a TonConnectError is returned and can be handled as described in the request errors section.

Handling Signed Data

from tonutils.tonconnect.utils.exceptions import TonConnectError, UserRejectsError

async with connector.pending_request_context(rpc_request_id) as response:
    if isinstance(response, TonConnectError):
        if isinstance(response, UserRejectsError):
            print("The user rejected the signing request.")
        else:
            print(f"Sign data error: {response.message}")
    else:
        key = connector.wallet.account.public_key
        if response.verify_sign_data(key):
            print("Verified sign data!")
        else:
            print("Failed to verify sign data!")

Handling the Transaction

from tonutils.tonconnect.utils.exceptions import TonConnectError, UserRejectsError

async with connector.pending_request_context(rpc_request_id) as response:
    if isinstance(response, TonConnectError):
        if isinstance(response, UserRejectsError):
            print("The user rejected the transaction.")
        else:
            print(f"Transaction error: {response.message}")
    else:
        print(f"Transaction sent successfully! Hash: {response.normalized_hash}")

Checking Request Status

To check whether a request is still waiting for user confirmation:

is_pending = connector.is_request_pending(rpc_request_id)

This method returns True if the request has not yet been confirmed in the user's wallet; otherwise, it returns False.

Cancelling a Request

If you need to cancel a request for any reason, use:

connector.cancel_pending_request(rpc_request_id)

This completely stops processing the request at the application level, even if the user later confirms it in the wallet.

Disconnecting the Wallet

To disconnect the user's wallet, call the disconnect_wallet method:

await connector.disconnect_wallet()

Event Handling

In addition to context managers, tonutils provides a unified event-driven interface for reacting to wallet actions. This allows you to handle events such as wallet connection, disconnection, transaction execution, and data signing through registered handlers.

Event Types

TON Connect emits two categories of events:

Success Events

These events are triggered when an action completes successfully:

• Event.CONNECT — emitted when a wallet is successfully connected. Parameters: user_id: int, wallet: WalletInfo

• Event.DISCONNECT — emitted when a wallet is disconnected. Parameters: user_id: int, wallet: WalletInfo

• Event.TRANSACTION — emitted when a transaction is confirmed by the user. Parameters: user_id: int, transaction: SendTransactionResponse, rpc_request_id: int

• Event.SIGN_DATA — emitted when a sign data request is approved. Parameters: user_id: int, sign_data: SignDataResponse, rpc_request_id: int

Error Events

These events are triggered if the corresponding action fails due to user rejection, timeout, or internal wallet/app errors:

• EventError.CONNECT — error during wallet connection.

• EventError.DISCONNECT — error during wallet disconnection.

• EventError.TRANSACTION — error during transaction confirmation.

• EventError.SIGN_DATA — error during sign data request.

  All error events receive:

  • user_id: int
  • error: TonConnectError

  Note: All error types are described in detail in the error handling section.

You can handle these errors the same way as standard events using register_event or decorators. This separation allows you to keep success and failure logic cleanly isolated.

Handling Events

You can register event handlers in two ways:

Using method

def on_transaction(user_id: int, transaction: SendTransactionResponse):
    print(f"Transaction received for user {user_id}")

tc.register_event(Event.TRANSACTION, on_transaction)

Using decorators

@tc.on_event(Event.TRANSACTION)
async def on_transaction(user_id: int, transaction: SendTransactionResponse):
    print(f"Transaction confirmed for user {user_id}")

Additional Parameters

In addition to standard event arguments, you can pass custom parameters (e.g., database session, context objects, comments) to your event handlers.

Attaching parameters to a specific event:

Use add_event_kwargs before entering the context manager or triggering the request:

connector.add_event_kwargs(
    event=Event.CONNECT,
    comment="Hello from tonutils!",
    db_session=session,
)

The extra keyword arguments will be passed directly to the corresponding handler:

@tc.on_event(Event.CONNECT)
async def on_connect(user_id: int, wallet: WalletInfo, comment: str, db_session: Session):
    ...

Defining global parameters for all events:

You can define default parameters for all events at the connector level:

tc = TonConnect(
    storage=TC_STORAGE,
    manifest_url=TC_MANIFEST_URL,
    wallets_fallback_file_path="./wallets.json"
)
tc["db_session"] = session
tc["comment"] = "Shared message"

These parameters will be available in all event handlers:

@tc.on_event(Event.SIGN_DATA)
async def on_sign_data(user_id: int, sign_data: SignDataResponse, db_session: Session, comment: str):
    ...

Error Handling

When working with TON Connect, errors may occur both during wallet connection and when sending requests.

Connection Errors

These errors can occur during the wallet connection initialization process:

Code	Error	Description
0	UnknownError	An unknown error occurred in the wallet during request processing.
1	BadRequestError	The request is malformed or contains invalid parameters.
2	ManifestNotFoundError	The specified manifest_url is unreachable or does not exist.
3	ManifestContentError	The manifest content has an invalid structure or is improperly formatted.
100	UnknownAppError	Application logic error while preparing the request data.
300	UserRejectsError	The user declined to connect their wallet to your application.
400	MethodNotSupportedError	The selected wallet does not support the requested operation or method.
500	RequestTimeoutError	The user did not complete the connection within the allotted time.

Request Errors

These errors may occur when processing requests.

Code	Error	Description
0	UnknownError	An unknown error occurred in the wallet during request processing.
1	BadRequestError	The request is malformed or contains invalid parameters.
100	UnknownAppError	Application logic error while preparing the request data.
300	UserRejectsError	The user rejected the request or refused to sign.
400	MethodNotSupportedError	The selected wallet does not support the requested operation or method.
500	RequestTimeoutError	The user did not confirm the request within the allotted time.

Conclusion

TON Connect provides a secure and user-friendly way to interact with wallets on the TON blockchain. With support for transaction signing, identity verification, and event handling, it enables seamless integration of wallet functionality into Python applications.

See also

• TON Connect usage examples
• Telegram bot with TON Connect

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