EstimateEnergy - Tron

Example code for the EstimateEnergy gRPC method. Complete guide on how to use EstimateEnergy gRPC method in GetBlock Web3 documentation.

This method estimates the Energy required to execute a smart-contract call, without submitting a transaction. It is used to set a fee limit before a call.

Service

This method is served by the protocol.Wallet service.

Method

rpc EstimateEnergy (TriggerSmartContract) returns (EstimateEnergyMessage)

Request Message

TriggerSmartContract

Field	Type	Description
owner_address	bytes	Caller address as raw bytes
contract_address	bytes	Contract address as raw bytes
data	bytes	ABI-encoded call data (selector + arguments)
call_value	int64	TRX in SUN to send with the call
fee_limit	int64	Maximum TRX in SUN to spend on Energy (write calls)

Request

grpcurl

grpcurl -H 'x-api-key: <ACCESS-TOKEN>' \
  -d '{"owner_address": "41f0cc5a2a84cd0f68ed1667070934542d673acbd8", "contract_address": "41a614f803b6fd780986a42c78ec9c7f77e6ded13c", "data": "a9059cbb..."}' \
  go.getblock.io:443 protocol.Wallet/EstimateEnergy

Python

example.py

import grpc
# Stubs generated from java-tron's api.proto with grpcio-tools
from api import api_pb2_grpc
from core import Contract_pb2, Tron_pb2

creds = grpc.ssl_channel_credentials()
channel = grpc.secure_channel('go.getblock.io:443', creds)
metadata = [('x-api-key', '<ACCESS-TOKEN>')]
stub = api_pb2_grpc.WalletStub(channel)

response = stub.EstimateEnergy(Contract_pb2.TriggerSmartContract(
    owner_address=bytes.fromhex('41f0cc5a2a84cd0f68ed1667070934542d673acbd8'),
    contract_address=bytes.fromhex('41a614f803b6fd780986a42c78ec9c7f77e6ded13c'),
    data=bytes.fromhex('a9059cbb...')), metadata=metadata)
print(response)

Go

example.go

conn, _ := grpc.Dial(
    "go.getblock.io:443",
    grpc.WithTransportCredentials(credentials.NewTLS(&tls.Config{})),
)
defer conn.Close()

client := api.NewWalletClient(conn)
ctx := metadata.AppendToOutgoingContext(
    context.Background(), "x-api-key", "<ACCESS-TOKEN>")

resp, _ := client.EstimateEnergy(ctx, &core.TriggerSmartContract{OwnerAddress: owner, ContractAddress: contract, Data: callData})
fmt.Println(resp)

Response Message

EstimateEnergyMessage

Field	Type	Description
result	Return	Whether the estimate succeeded
energy_required	int64	Estimated Energy the call will consume

Use Cases

• Fee Limits: Set fee_limit from the estimated Energy

• Cost Preview: Show a user the Energy cost of an action

• Preflight: Detect a call that would fail before submitting

• Batch Sizing: Sum estimates across a batch of calls

Error Handling

Code	Status	Description
3	INVALID_ARGUMENT	A request field is missing or malformed
5	NOT_FOUND	The requested account, block, or transaction does not exist
16	UNAUTHENTICATED	The access token is missing or invalid
13	INTERNAL	The node failed to process the request