pypolkadot 0.2.0

Python light client for Polkadot/Substrate via smoldot

pypolkadot

Experimental Python light client for Polkadot/Substrate via smoldot.

Connect to Polkadot blockchains trustlessly - no full node, no RPC provider needed.

This is a feasibility demonstrator to integrate the functionality in https://github.com/JAMdotTech/py-polkadot-sdk.

Installation

pip install pypolkadot

Quick Start

from pypolkadot import LightClient

# Connect to Polkadot mainnet (embedded light client)
client = LightClient()

# Query storage
total = client.storage("Balances", "TotalIssuance")
print(f"Total issuance: {total}")

# Get events
for event in client.events(pallet="System"):
    print(f"{event.pallet}.{event.name}")

# Subscribe to blocks
for block in client.subscribe_finalized():
    print(f"Block #{block.number}: {block.hash}")

Features

• Verifies proofs cryptographically, no RPC trust required
• Light client runs in-process, no external dependencies
• Query any storage/events without codegen
• Simple Python API, no async/await required

API

Method	Description
LightClient()	Connect to Polkadot mainnet
LightClient(testnet=True)	Connect to Polkadot mainnet
LightClient.from_chain_spec(json)	Connect with custom chain spec
client.storage(pallet, entry, keys)	Query storage
client.events(block_hash, pallet, name)	Get/filter events
client.submit(signed_hex)	Submit pre-signed extrinsic
client.subscribe_finalized()	Stream finalized blocks

Development

# Setup
uv venv && source .venv/bin/activate
pip install maturin

# Build
maturin develop

# Test
python tests/test_storage.py

License

GPL-3.0 as intended.