state_getRuntimeVersion | Bittensor RPC Docs

Get the runtime version on Bittensor. Essential for compatibility checking, upgrade detection, and transaction construction on the decentralized machine intelligence network built around subnets, TAO staking, and validator-miner coordination.

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

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.

When to Use This Method

state_getRuntimeVersion is essential for AI/ML developers, subnet operators, and teams building decentralized machine learning applications:

Version Checking — Verify runtime compatibility before constructing transactions on Bittensor
Upgrade Detection — Monitor for runtime upgrades that may change chain behavior for decentralized AI inference, subnet-specific AI models, TAO staking, and cross-subnet AI collaboration
Transaction Construction — Include the correct specVersion and transactionVersion in signed extrinsics
API Compatibility — Check which runtime APIs are available and at what version

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 Code	Description	Solution
-32603	Internal error	Node may be syncing — retry with backoff
-32602	Invalid params	Verify block hash format is valid hex with `0x` prefix
-32601	Method not found	Verify the node supports this RPC method
-32005	Rate limit exceeded	Implement client-side rate limiting

state_getMetadata — Get full runtime metadata for decoding
system_version — Get node software version
chain_subscribeFinalizedHeads — Subscribe to detect upgrade blocks

state_getRuntimeVersion - Bittensor RPC Method

When to Use This Method

Code Examples

Common Use Cases

1. Runtime Upgrade Monitor

2. Transaction Construction with Correct Version

3. Historical Version Comparison

Error Handling

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