GenLayerPY

About

GenLayerPY SDK is a python library designed for developers building decentralized applications (Dapps) on the GenLayer protocol. This SDK provides a comprehensive set of tools to interact with the GenLayer network, including client creation, transaction handling, event subscriptions, and more, all while leveraging the power of web3.py as the underlying blockchain client.

Prerequisites

Before installing GenLayerPY SDK, ensure you have the following prerequisites installed:

• Python (>=3.12)

🛠️ Installation and Usage

To install the GenLayerPY SDK, use the following command:

$ pip install genlayer-py

SDK releases follow their corresponding GenLayer protocol release. This release targets the current resolution-kernel train; use the matching older SDK release when connecting to an older deployment.

Use the dedicated preview preset for the release-candidate Studio deployment:

from genlayer_py import create_client
from genlayer_py.chains import studio_devnet

client = create_client(chain=studio_devnet)

studio_devnet targets https://studio-dev.genlayer.com/api (chain ID 61997). The existing studionet preset remains pinned to the stable hosted Studio.

Here’s how to initialize the client and connect to the GenLayer Simulator:

Reading a Transaction

from genlayer_py import create_client
from genlayer_py.chains import localnet

client = create_client(
    chain=localnet,
)

transaction_hash = "0x..."

transaction = client.get_transaction(hash=transaction_hash)

Waiting for Transaction Receipt

from genlayer_py import create_client
from genlayer_py.chains import localnet

client = create_client(chain=localnet)

# Get simplified receipt (default - removes binary data, keeps execution results)
receipt = client.wait_for_transaction_receipt(
    transaction_hash="0x...",
    wait_until="finalized",
    full_transaction=False  # Default - simplified for readability
)

# Get complete receipt with all fields
full_receipt = client.wait_for_transaction_receipt(
    transaction_hash="0x...",
    wait_until="finalized",
    full_transaction=True  # Complete receipt with all internal data
)

Reading a contract

from genlayer_py import create_client
from genlayer_py.chains import localnet

client = create_client(
    chain=localnet,
)

result = client.read_contract(
    address=contract_address,
    function_name='get_complete_storage',
    args=[],
    state_status='accepted'
)

Writing a transaction

from genlayer_py.chains import localnet
from genlayer_py import create_client, create_account

client = create_client(
    chain=localnet,
)

account = create_account()

transaction_hash = client.write_contract(
    account=account,
    transaction=transaction,
    address=contract_address,
    function_name='account',
    args=['new_storage'],
    value=0, // value is optional, if you want to send some native token to the contract
)
receipt = client.wait_for_transaction_receipt(
    hash=transaction_hash,
    wait_until="finalized",
    full_transaction=False  // False by default - returns simplified receipt for better readability
)

Fee presets for transactions

Apps can build a trusted fee preset once they know the transaction shape, then submit the same preset with the transaction. The user may still override these values in wallet or app UI before signing.

estimate = client.estimate_transaction_fees(
    {
        "leaderTimeunitsAllocation": 100,
        "validatorTimeunitsAllocation": 200,
    }
)

tx_hash = client.write_contract(
    account=account,
    address=contract_address,
    function_name="update_storage",
    args=["new_storage"],
    fees={
        "distribution": estimate["distribution"],
        "feeValue": estimate["feeValue"],
    },
)

When rotations is omitted, estimates fund chain.default_consensus_max_rotations for the initial round and every enabled appeal round. Pass an explicit list, including [0], when the application wants to fund a different number of rotations.

If fees["distribution"] is provided without feeValue, the SDK derives the fee deposit from FeeManager on network backends, or from sim_getFeeConfig on Studio. Use messageAllocations with estimate_transaction_fees for transactions that can emit funded messages. For method-specific message budgets, derive the same call key GenVM reports in fee accounting:

from genlayer_py.transactions import (
    MessageType,
    derive_external_message_call_key,
    derive_internal_message_call_key,
    encode_external_message_fee_params,
    encode_internal_message_fee_params,
)

estimate = client.estimate_transaction_fees(
    {
        "messageAllocations": [
            {
                "messageType": MessageType.Internal,
                "onAcceptance": True,
                "recipient": contract_address,
                "callKey": derive_internal_message_call_key("update_storage"),
                "budget": 55,
                "feeParams": encode_internal_message_fee_params(),
            },
            {
                "messageType": MessageType.External,
                "onAcceptance": False,
                "recipient": "0x3333333333333333333333333333333333333333",
                "callKey": derive_external_message_call_key("0xaabbccdd"),
                "budget": 210_000,
                "feeParams": encode_external_message_fee_params(
                    {"gasLimit": 21_000, "maxGasPrice": 10}
                ),
            },
        ],
    }
)

For a concrete Studio/localnet write, use the one-call helper. The SDK sends an initial fee budget to sim_estimateTransactionFees; Studio simulates the write without committing state and returns the authoritative recommended preset.

recommended = client.estimate_transaction_fees_for_write(
    account=account,
    address=contract_address,
    function_name="update_storage",
    args=["new_storage"],
)

tx_hash = client.write_contract(
    account=account,
    address=contract_address,
    function_name="update_storage",
    args=["new_storage"],
    fees={
        "distribution": recommended["distribution"],
        "messageAllocations": recommended.get("messageAllocations"),
        "feeValue": recommended["feeValue"],
    },
)

For tests or tools that need to inspect the raw simulation, use the explicit two-step flow. simulate_write_contract uses sim_call; the returned receipt includes the fee accounting report produced by GenVM and Studio:

simulation = client.simulate_write_contract(
    account=account,
    address=contract_address,
    function_name="update_storage",
    args=["new_storage"],
    fees={
        "distribution": estimate["distribution"],
        "feeValue": estimate["feeValue"],
    },
)

print(simulation["genvm_result"]["fee_accounting"])

To reuse a representative Studio simulation as the trusted preset source, pass the simulation result into estimate_transaction_fees_from_simulation:

estimate = client.estimate_transaction_fees_from_simulation(
    {
        "simulation": simulation,
    }
)

tx_hash = client.write_contract(
    account=account,
    address=contract_address,
    function_name="update_storage",
    args=["new_storage"],
    fees={
        "distribution": estimate["distribution"],
        "messageAllocations": estimate.get("messageAllocations"),
        "feeValue": estimate["feeValue"],
    },
)

For transactions that are already submitted, use the fee-management helpers:

client.top_up_fees(
    transaction_id=tx_hash,
    value=1_100,
    distribution={
        "leaderTimeunitsAllocation": 100,
        "validatorTimeunitsAllocation": 200,
        "rotations": [0],
    },
)

quote = client.get_appeal_quote(tx_hash)
if client.can_appeal(tx_hash, expected_decision_id=quote["decision_id"]):
    client.top_up_and_submit_appeal(
        transaction_id=tx_hash,
        expected_decision_id=quote["decision_id"],
        value=quote["total"],
        distribution={
            "appealRounds": 1,
            "rotations": [0, 0],
        },
    )

top_up_fees returns the backend RPC hash. On network backends this is the EVM transaction hash; on Studio/localnet it is the target GenLayer transaction id. Appeal commands are guarded by the quoted decision id so a stale request cannot bind to a newer decision. If the id and value are omitted, the SDK refreshes this lightweight quote automatically. This applies to deployed Consensus. Current Studio uses its native decision-free appeal methods: pass value explicitly and omit expected_decision_id.

Checking execution results

A transaction can be finalized by consensus but still have a failed execution. Always check tx_execution_result before reading contract state:

from genlayer_py import create_client, create_account
from genlayer_py.chains import testnet_bradbury
from genlayer_py.types import ExecutionResult

client = create_client(chain=testnet_bradbury, account=create_account())

receipt = client.wait_for_transaction_receipt(
    transaction_hash=tx_hash,
    wait_until="finalized",
)

if receipt.get("tx_execution_result_name") == ExecutionResult.FINISHED_WITH_RETURN.value:
    # Execution succeeded — safe to read state
    result = client.read_contract(
        address=contract_address,
        function_name="get_storage",
        args=[],
    )
elif receipt.get("tx_execution_result_name") == ExecutionResult.FINISHED_WITH_ERROR.value:
    # Execution failed — contract state was not modified
    raise RuntimeError("Contract execution failed")
else:
    # NOT_VOTED — execution hasn't completed
    print("Execution result not yet available")

Fetching emitted messages and triggered transactions

Transactions can emit messages to other contracts. These messages create new child transactions when processed:

tx = client.get_transaction(transaction_hash=tx_hash)

# The default lifecycle is derived only from stored chain state.
print(tx["lifecycle"])
# {"state": "processing", "phase": "revealing"}
# {"state": "decided", "outcome": "accepted"}

# Protocol projection/action details are available only through the explicit
# advanced API.
raw_lifecycle = client.get_transaction_lifecycle(transaction_hash=tx_hash)
print(raw_lifecycle["stored_status_name"])
print(raw_lifecycle["projected_status_name"])
print(raw_lifecycle["resolution_action_name"])
print(raw_lifecycle["resolution_source_name"])
# `resolution_action_name == "Finalize"` is the authoritative readiness verdict.
# On current Studio without the advanced lifecycle RPC, only stored status is
# provable; projection repeats it and resolution/decision fields stay inactive.

# The train stores the execution hash, not the old receipt bytes.
print(tx["tx_execution_hash"])
# `tx_receipt` remains present but is `None` when the
# protocol cannot supply the old bytes.

# Messages emitted by the contract during execution
print(tx["messages"])
# [{"messageType": 1, "recipient": "0x...", "value": 0, "data": "0x...", "onAcceptance": True, "saltNonce": 0}, ...]

# Child transaction IDs created from those messages (separate call)
child_tx_ids = client.get_triggered_transaction_ids(transaction_hash=tx_hash)
print(child_tx_ids)
# ["0xabc...", "0xdef..."]

Active and joined validators

The active set contains only validators currently eligible for protocol duties. The joined registry is broader and can include validators that are not yet selectable, are under-staked, or are otherwise unavailable.

active = client.active_validators()
active_count = client.active_validators_count()

joined = client.joined_validators()
joined_count = client.joined_validators_count()

Debugging transaction execution

Use debug_trace_transaction to inspect the full execution trace of a transaction, including return data, errors, and GenVM logs:

trace = client.debug_trace_transaction(
    transaction_hash=tx_hash,
    round=0,  # optional, defaults to 0
)

print(trace["result_code"])   # 0=success, 1=user error, 2=VM error
print(trace["return_data"])   # hex-encoded contract return data
print(trace["stderr"])        # standard error output
print(trace["genvm_log"])     # detailed GenVM execution logs

🚀 Key Features

• Client Creation: Easily create and configure a client to connect to GenLayer’s network.
• Transaction Handling: Send and manage transactions on the GenLayer network.
• Gas Estimation: Estimate gas fees for executing transactions on GenLayer.

* under development

📖 Documentation

For detailed information on how to use GenLayerPY SDK, please refer to our documentation.

Contributing

We welcome contributions to GenLayerPY SDK! Whether it's new features, improved infrastructure, or better documentation, your input is valuable. Please read our CONTRIBUTING guide for guidelines on how to submit your contributions.

License

This project is licensed under the MIT License - see the LICENSE file for details.