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🧩 Jot Examples

Runnable examples demonstrating how to use the Jot (Polkadot Java SDK) to connect to a node, query on-chain data, and submit transactions.

All examples are configured for the Westend test network and are designed to run successfully when using a funded test account.

💡 Note: For examples that submit extrinsics, successfully means the transaction is broadcast to the blockchain and a valid transaction hash is returned. Some calls may still fail at the protocol level (for example, attempting Staking.unbond on an account that is not currently staking).

⚙️ Configure Endpoint & Wallet

All configuration lives in:

com.method5.jot.examples.Config

Edit this file to set:

  • WSS endpoint(s) for relay chain (default recommended: wss://westend.api.onfinality.io/public-ws)
  • WSS endpoint(s) for asset hub (default recommended: wss://asset-hub-westend-rpc.n.dwellir.com)
  • Wallet mnemonic phrase (12 or 24 words) for a funded Westend account. See "Out of Funds" - How to Fix

▶️ How to Run

# Build everything
mvn -q -DskipTests clean install

# Change to jot-examples module directory
cd jot-examples

# Run a specific example (Replace class with one below)
mvn exec:java -Dexec.mainClass="com.method5.jot.examples.query.QueryAccountAndBalanceExample"

# Run all examples not requiring funds
mvn exec:java -Dexec.mainClass="com.method5.jot.util.RunAllReadOnly"

# Run all examples (requires funded wallet)
mvn exec:java -Dexec.mainClass="com.method5.jot.util.RunAll"

📚 Examples

🔍 Queries (com.method5.jot.examples.query)

Example Description
ManualQueryExample Perform a manual RPC query with raw parameters and inspect the JSON response.
QueryAccountAndBalanceExample Retrieve system.account data and balances for a given address.
QueryAssetBalanceExample Query balances for assets on Asset Hub.
OfflineSigningExample Sign an extrinic offline.
QueryBlockExample Fetch a block and print its contents.
QueryBlockHashExample Resolve block numbers to block hashes.
QueryBlockHeaderExample Query and decode block headers.
QueryBlockEventsExample Read and decode system events for a specific block.
QueryFeeInfoExample Retrieve fee and weight information for a call.
QueryFinalizedHeadExample Get the hash of the latest finalized block.
QueryMetadataExample Retrieve and decode runtime metadata.
QueryNonceExample Query an account’s current transaction nonce.
QueryRuntimeVersionExample Get the runtime version and spec information.
QuerySystemDetailsExample Fetch chain name, properties, and node system info.

🔢 SCALE Encoding (com.method5.jot.examples.scale)

Example Description
ScaleEncodingExample Demonstrate how to encode and decode values using the SCALE codec.

🏷️ SS58 (com.method5.jot.examples.ss58)

Example Description
AddressConversionExample Convert between public keys and SS58 addresses across networks.

🧠 Subscriptions (com.method5.jot.examples.subscription)

Example Description
SubscribeAllHeadsExample Subscribe to all new block headers.
SubscribeBestHeadsExample Subscribe to best (non-finalized) block headers.
SubscribeFinalizedHeadsExample Subscribe to finalized block headers.
SubscribeLatestHeadsExample Stream the latest block headers in real time.
SubscribeRuntimeVersionExample Subscribe to runtime version updates.

💸 Extrinsics (com.method5.jot.examples.extrinsic)

Example Description
ReceiveExtrinsicResultExample Submit an extrinsic and wait for inclusion/finalization events.
BalancesTransferAllExample Submit a balances.transferAll transaction.
BalancesTransferAllowDeathExample Submit a balances.transferAllowDeath transaction.
BalancesTransferKeepAliveExample Submit a balances.transferKeepAlive transaction.
ConvictionVotingVoteExample Cast a governance vote using conviction voting.
ConvictionVotingRemoveVoteExample Remove a previously cast governance vote.
MultisigAsMultiExample Create and send a multisig transaction with multiple signers.
MultisigApproveAsMultiExample Approve and execute an existing multisig transaction.
StakingBondExample Bond funds to become a nominator or validator.
StakingBondExtraExample Add additional bonded funds.
StakingChillExample Stop nominating (chill).
StakingNominateExample Nominate validators.
StakingPayoutStakersExample Payout staking rewards for a given era.
StakingRebondExample Rebond previously unbonded funds.
StakingUnbondExample Unbond part of your staking balance.
SystemRemarkExample Submit an on-chain remark message.
UtilityBatchExample Send multiple calls in a single batched transaction.
UtilityBatchAllExample Send multiple calls in an atomic batch (batch_all).
UtilityForceBatchExample Force batch multiple calls, continuing on errors.

🔑 Keys (com.method5.jot.examples.keys)

Example Description
Ed25519WalletExample Generate, sign, and verify using Ed25519 keys.
GenericWalletExample Demonstrate wallet creation, SS58 address derivation, and signing.

🧩 Metadata (com.method5.jot.examples.metadata)

Example Description
ParsingMetadataExample Parse and inspect runtime metadata (modules, calls, events, constants).

💰 “Out of Funds” — How to Fix

Transaction examples need WND to cover fees. If you see errors like Inability to pay some fees:

  1. Open the Polkadot Faucet: https://faucet.polkadot.io/
  2. Select Westend.
  3. Paste your Westend address (from Config.java).
  4. Complete the CAPTCHA and request funds.

Most examples work best with ≥ 1 WND (Westend uses 12 decimals).

📝 Notes

  • Target network: Westend (testnet).
  • Query-only examples (Wallet utility, RPC, subscriptions) run without funds.
  • Transaction examples require a funded mnemonic; they may gracefully skip if no balance is detected (depending on the example).
  • Jot GitHub: https://github.com/methodfive/jot
  • Jot Docs: https://methodfive.github.io/jot/
  • Westend Faucet: https://faucet.polkadot.io/
  • Westend Explorer: https://westend.subscan.io