Skip to main content
The admin_* namespace provides administrative methods for node operators to manage validator operations and inspect node configuration.
Admin methods should be protected and only accessible to trusted operators. Configure RPC access control appropriately.

​
admin_validatorKey

Returns the validator public key if this node is configured as a validator.
​
result
bytes32 | null
Ed25519 public key used by this node for validator operations in the consensus layer. Returns null if the node is not configured as a validator.
Example Request: 
{
  "jsonrpc": "2.0",
  "method": "admin_validatorKey",
  "params": [],
  "id": 1
}
Example Response (Validator Node): 
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef"
}
Example Response (Non-Validator Node): 
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": null
}

​
Use Cases

​
Validator Identity Verification

Validators can use this method to verify their node is correctly configured with the expected public key: 
curl -X POST http://localhost:8545 \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "admin_validatorKey",
    "params": [],
    "id": 1
  }'

​
Monitoring and Alerting

Monitoring systems can query this endpoint to:
  • Verify validator nodes are properly configured
  • Track which nodes in a cluster are validators
  • Alert if a validator’s configuration changes unexpectedly

​
Subblock Transaction Routing

Applications can query the validator key to determine:
  • If this node accepts subblock transactions
  • The partial validator key to include in subblock transaction requests
  • Whether to route subblock transactions to this specific node

​
Implementation Details

The validator key is:
  • Configured at node startup via command-line arguments or configuration file
  • Stored in TempoAdminApi instance created during node initialization
  • Used by the RPC layer to filter incoming subblock transactions
  • Never changed during node runtime (requires restart to modify)
Source: crates/node/src/rpc/admin.rs:1-35

​
Security Considerations

Do not expose admin endpoints publiclyThe validator key, while public information on-chain, should not be arbitrarily exposed via RPC to untrusted parties.
Bind admin methods to localhost only: 
# tempo.toml
[rpc]
addr = "127.0.0.1:8545"
api = ["eth", "net", "web3", "consensus", "token"]

[rpc.admin]
addr = "127.0.0.1:8546"
api = ["admin"]
Or use authentication middleware to protect admin endpoints.

​
Future Admin Methods

Additional admin methods may be added for:
  • Node health and diagnostics
  • Transaction pool management
  • Peer management
  • Consensus layer debugging
Check the GitHub repository for the latest admin API additions.