eth_signTransaction - Bittensor RPC Method

Signs a transaction with the private key of the specified account on Bittensor without submitting it to the network.

Why Bittensor? Build on the decentralized machine intelligence network built around subnets, TAO staking, and validator-miner coordination with Yuma Consensus, subnet-based specialization, dual Substrate and EVM surfaces, and onchain incentive coordination.

Security Warning: Public Dwellir endpoints do not keep unlocked signers. On shared infrastructure, eth_signTransaction commonly returns a deprecation, unsupported-method, or account-management error instead of a signed payload. For production use, sign transactions client-side using libraries like ethers.js or web3.py, then broadcast with eth_sendRawTransaction.

When to Use This Method

eth_signTransaction is relevant for AI/ML developers, subnet operators, and teams building decentralized machine learning applications in limited scenarios:

• Understanding the Signing Flow — Learn how transaction signing works before implementing client-side signing
• Local Development — Sign transactions on a local dev node (Hardhat, Anvil, Ganache) where accounts are unlocked
• Offline Signing Workflows — Generate signed transaction payloads for later broadcast

Code Examples

# Local dev node only. Public Dwellir endpoints do not expose unlocked-account signing.
curl -X POST http://127.0.0.1:8545 \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_signTransaction",
    "params": [{
      "from": "0x407d73d8a49eeb85d32cf465507dd71d507100c1",
      "to": "0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b",
      "gas": "0x76c0",
      "gasPrice": "0x9184e72a000",
      "value": "0x9184e72a",
      "nonce": "0x0"
    }],
    "id": 1
  }'

Common Use Cases

1. Offline Transaction Signing

Sign transactions on an air-gapped machine for later broadcast:

import { Wallet } from 'ethers';

async function createSignedTransaction(privateKey, to, value, { chainId, nonce, gasLimit }) {
  const wallet = new Wallet(privateKey);
  const tx = {
    to,
    value,
    gasLimit,
    nonce,
    chainId,
  };

  const signedTx = await wallet.signTransaction(tx);
  // Store signedTx and broadcast from an online machine
  return signedTx;
}

2. Batch Transaction Preparation

Pre-sign multiple transactions for sequential submission on Bittensor:

async function prepareBatch(wallet, transactions) {
  const signed = [];

  for (let i = 0; i < transactions.length; i++) {
    const tx = {
      ...transactions[i],
      nonce: baseNonce + i
    };
    signed.push(await wallet.signTransaction(tx));
  }

  return signed; // Submit via eth_sendRawTransaction in order
}

Error Handling

Common errors and solutions:

Related Methods

• eth_sendRawTransaction — Broadcast a signed transaction
• eth_sendTransaction — Sign and send in one step (requires unlocked account)
• eth_accounts — List accounts available for signing