Leader slot API

Cached upcoming Solana leader slots with rpc edge route quality for transaction routing decisions.

getLeaderSlots is an rpc edge JSON-RPC extension for transaction senders. It returns upcoming Solana leader slots plus measured rpc edge route quality, so a client can choose where to submit transactions before the slot arrives.

This is not an Agave RPC method. The gateway serves it from a local cache fed by rpc edge routing telemetry and the Solana leader schedule.

Request

Use the normal JSON-RPC endpoint:

https://rpc.rpcedge.com
https://frankfurt.rpc.rpcedge.com

Authenticate like other RPC calls. Supported forms include:

x-token: YOUR_UUID_KEY
x-api-key: YOUR_UUID_KEY
authorization: Bearer YOUR_UUID_KEY
?key=YOUR_UUID_KEY

Call getLeaderSlots as a single JSON-RPC request:

curl -s https://rpc.rpcedge.com \
  -H 'content-type: application/json' \
  -H 'x-token: YOUR_UUID_KEY' \
  -d '{"jsonrpc":"2.0","id":1,"method":"getLeaderSlots","params":[429641447,10]}'

Parameters

Position	Name	Type	Notes
`0`	`startSlot`	`u64`	First slot to return. Use a recent current slot for live routing.
`1`	`limit`	`u64`	Optional. Defaults to the gateway default and is capped at `100` in v1.

Batch requests containing getLeaderSlots are rejected in v1. Send this method as its own JSON-RPC request.

Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "success": true,
    "total": 2,
    "data": [
      {
        "slot": 429641447,
        "identity": "validatorIdentityPubkey",
        "stake": 123456789,
        "location": {
          "dataCenterKey": "fra",
          "region": "frankfurt",
          "latitude": 50.11,
          "longitude": 8.68
        },
        "pingToLeaders": [
          {
            "region": "frankfurt",
            "latencyMs": 2,
            "estimated": false
          }
        ],
        "txPaths": [
          {
            "provider": "rpcedge",
            "pathRegion": "frankfurt",
            "latencyMs": 3,
            "measured": true,
            "doublezeroAvailable": false,
            "selected": true
          }
        ],
        "routeScores": [
          {
            "active_region": "frankfurt",
            "market_latency_ms": 2,
            "tx_latency_ms": 3,
            "score_ms": 5,
            "selected": true
          }
        ]
      }
    ],
    "snapshotSlot": 429641440,
    "snapshotGeneratedAtUnixMs": 1782748800000,
    "snapshotAgeMs": 350
  }
}

Field semantics

Field	Meaning
`slot`	Solana slot covered by this row.
`identity`	Scheduled leader validator identity.
`stake`	Leader stake from the schedule metadata source.
`location`	Best-known leader location metadata, if available.
`pingToLeaders`	Region-to-leader latency estimates or measurements.
`txPaths`	Available rpc edge transaction paths for the leader.
`routeScores`	Combined route score by active region. Lower is better.
`snapshotSlot`	Solana slot used when the snapshot was built.
`snapshotAgeMs`	Gateway-side age of the cached snapshot.

routeScores[].score_ms is currently market_latency_ms + tx_latency_ms. Treat route scores as advisory routing inputs, not a guarantee that a later transaction lands.

Errors and staleness

The gateway fails closed if the cached leader-slot snapshot is missing, stale, outside the requested slot range, or on an unsupported schema version. The response is a normal JSON-RPC error with your request id preserved.

Common recovery behavior:

Error family	Client behavior
Cache empty or stale	Retry after a short delay, or fall back to your default transaction path.
Requested range not covered	Refresh your current slot and request a smaller near-future range.
Unsupported schema	Treat as incompatible and alert; this should be rare.