Docs

state_getRuntimeVersion - Polkadot RPC Method

Get the runtime version on Polkadot. Essential for compatibility checking, upgrade detection, and transaction construction on the heterogeneous multi-chain protocol with $300M+ DeFi TVL and JAM supercomputer upgrade incoming.

Returns the runtime version information for Polkadot, including the spec name, spec version, implementation version, and supported API versions.

Why Polkadot? Build on the heterogeneous multi-chain protocol with $300M+ DeFi TVL and JAM supercomputer upgrade incoming with shared relay chain security, XCM cross-chain messaging, JAM upgrade targeting 1M TPS, and 2.1B DOT supply cap.

When to Use This Method

state_getRuntimeVersion is essential for parachain developers, cross-chain dApp builders, and teams requiring shared security:

  • Version Checking — Verify runtime compatibility before constructing transactions on Polkadot
  • Upgrade Detection — Monitor for runtime upgrades that may change chain behavior for cross-chain DeFi, parachain deployment, XCM interoperability, and DOT staking (8-10% APY)
  • Transaction Construction — Include the correct specVersion and transactionVersion in signed extrinsics
  • API Compatibility — Check which runtime APIs are available and at what version

Code Examples

Common Use Cases

1. Runtime Upgrade Monitor

Detect runtime upgrades on Polkadot in real time:

JavaScript
async function monitorUpgrades(api) {
  let currentVersion = (await api.rpc.state.getRuntimeVersion()).specVersion.toNumber();
  console.log(`Starting monitor at spec version: ${currentVersion}`);

  const unsub = await api.rpc.chain.subscribeNewHeads(async (header) => {
    const version = await api.rpc.state.getRuntimeVersion(header.hash);
    const newVersion = version.specVersion.toNumber();

    if (newVersion !== currentVersion) {
      console.log(`Runtime upgrade detected! ${currentVersion} -> ${newVersion}`);
      currentVersion = newVersion;
      // Trigger reconnection or metadata refresh
    }
  });

  return unsub;
}

2. Transaction Construction with Correct Version

Include the correct version fields when constructing signed extrinsics:

JavaScript
async function getSigningPayloadInfo(api) {
  const version = await api.rpc.state.getRuntimeVersion();
  const genesisHash = await api.rpc.chain.getBlockHash(0);

  return {
    specVersion: version.specVersion.toNumber(),
    transactionVersion: version.transactionVersion.toNumber(),
    genesisHash: genesisHash.toHex(),
    // These fields are required for signing extrinsics
  };
}

3. Historical Version Comparison

Compare runtime versions across blocks to identify upgrade boundaries:

JavaScript
async function findUpgradeBlock(api, startBlock, endBlock) {
  const startHash = await api.rpc.chain.getBlockHash(startBlock);
  const startVersion = (await api.rpc.state.getRuntimeVersion(startHash)).specVersion.toNumber();

  // Binary search for upgrade block
  let low = startBlock;
  let high = endBlock;

  while (low < high) {
    const mid = Math.floor((low + high) / 2);
    const midHash = await api.rpc.chain.getBlockHash(mid);
    const midVersion = (await api.rpc.state.getRuntimeVersion(midHash)).specVersion.toNumber();

    if (midVersion === startVersion) {
      low = mid + 1;
    } else {
      high = mid;
    }
  }

  console.log(`Runtime upgraded at block #${low}`);
  return low;
}

Error Handling

Error CodeDescriptionSolution
-32603Internal errorNode may be syncing — retry with backoff
-32602Invalid paramsVerify block hash format is valid hex with 0x prefix
-32601Method not foundVerify the node supports this RPC method
-32005Rate limit exceededImplement client-side rate limiting