The getLeaderSchedule RPC method returns the assignment of block production leadership to validators for a specific epoch. Understanding the leader schedule can be useful for network analysis, predicting which validator will produce blocks at certain times, or for tools that interact with specific leaders.

​
Common Use Cases

  • Network Monitoring: Observe the distribution of leader slots among validators in an epoch.
  • Transaction Routing (Advanced): Some advanced applications might try to route transactions to the current or upcoming leader, though this is generally handled by the network and RPC nodes.
  • Validator Performance Analysis: Correlate the leader schedule with actual block production to assess validator uptime and performance.
  • Understanding Epoch Progression: See which validators are responsible for producing blocks throughout an epoch.

​
Request Parameters

The method can take up to two optional parameters:

  1. slot (u64, optional): A slot number. If provided, the leader schedule for the epoch containing this slot will be fetched. If null or omitted, the leader schedule for the current epoch is fetched.
  2. config (object, optional): A configuration object that can contain:
    • commitment (string, optional): Specifies the commitment level. If not provided, the node’s default commitment is used.
    • identity (string, optional): A base-58 encoded public key of a validator. If provided, the returned schedule will only include slots assigned to this specific validator.

​
Response Structure

The result field of the JSON-RPC response will be:

  • null: If the epoch corresponding to the requested slot (or current epoch if no slot is provided) is not found or its leader schedule is not available (e.g., for a future, uncalculated epoch).
  • An object: If a schedule is found. This object is a map where:
    • Each key is the base-58 encoded public key (identity) of a validator.
    • The corresponding value is an array of numbers. Each number is a slot index relative to the start of the epoch for which that validator is the leader.

For example, if an epoch starts at slot 1000 and a validator has [0, 1, 5] in its schedule, it means that validator is the leader for slots 1000, 1001, and 1005.

​
Examples

​
1. Get Leader Schedule for the Current Epoch

This example fetches the complete leader schedule for the current epoch.

# Replace <api-key> with your Helius API key
curl https://mainnet.helius-rpc.com/?api-key=<api-key> -X POST -H "Content-Type: application/json" -d \
  '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getLeaderSchedule"
  }'

​
2. Get Leader Schedule for a Specific Validator in a Specific Epoch (by Slot)

This example fetches the leader schedule for a given validator identity for the epoch containing slot 200000.

# Replace <api-key> with your Helius API key
# Replace VALIDATOR_PUBKEY with an actual validator identity public key
curl https://mainnet.helius-rpc.com/?api-key=<api-key> -X POST -H "Content-Type: application/json" -d \
  '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getLeaderSchedule",
    "params": [
      200000,
      { "identity": "VALIDATOR_PUBKEY" }
    ]
  }'

​
Developer Tips

  • Epoch Boundaries: The leader schedule is fixed for an entire epoch. You can use getEpochInfo to find the start and end slots of an epoch.
  • Future Epochs: Requesting the schedule for an epoch far in the future might return null if the network hasn’t calculated it yet.
  • Relative Slot Indices: Remember that the slot numbers in the response are relative to the first slot of the requested epoch, not absolute slot numbers on the blockchain.
  • Large Response: For a full epoch schedule without an identity filter, the response can be large, listing all validators and their assigned slots.

This guide provides the necessary information to use getLeaderSchedule to query block producer assignments for any given epoch on the Solana network.