getFeeForMessage - Solana

The getFeeForMessage JSON-RPC method retrieves the fee the Solana network will charge for processing a specific message. This method is a crucial part of the Solana getFeeForMessage API, enabling Web3

This method is only available in solana-core v1.9 or newer. For solana-core v1.8 and below, use the getFees method instead.

The getFeeForMessage method calculates the transaction fee for a given Base-64 encoded message at a specific blockhash. It helps developers estimate the cost of executing transactions before submission, ensuring better fee management and optimization within the Solana network.

Supported Networks

This method is accessible through Solana API endpoints:

• Mainnet

• Devnet

Parameters

Required Parameters

• message (string): A Base-64 encoded transaction message.

Optional Parameters

• commitment (string): Defines the finality level of the response.

• minContextSlot (number): The minimum slot at which the request should be evaluated.

Request Example

API Endpoints

https://go.getblock.io/<ACCESS-TOKEN>/

cURL Example

curl

curl --location "https://go.getblock.io/<ACCESS-TOKEN>/" -XPOST \
--header "Content-Type: application/json" \
--data '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getFeeForMessage",
    "params": [
        "AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEBAQAA",
        {
            "commitment": "processed"
        }
    ]
}'

Response

A successful getFeeForMessage example response returns the fee associated with the given message at the specified blockhash.

Example Response

{
  "jsonrpc": "2.0",
  "result": { "context": { "slot": 5068 }, "value": 5000 },
  "id": 1
}

Error Handling

Common getFeeForMessage error scenarios:

• Invalid Base-64 message format: If the provided message is improperly encoded.

• Missing or expired blockhash: The blockhash used in the message has expired.

• Network connectivity issues: If the request fails due to API unavailability.

Example Error Response

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32000,
    "message": "Blockhash not found"
  },
  "id": 1
}

Use Cases

The Solana getFeeForMessage method is essential for:

• Wallet applications: Estimating transaction fees before signing.

• Smart contract interactions: Calculating transaction costs in Web3 getFeeForMessage applications.

• Blockchain explorers: Displaying estimated transaction fees for pending transactions.

• Developers: Ensuring users have sufficient SOL before submitting a transaction.

Code Example – Web3 getFeeForMessage Integration

JavaScript

const axios = require('axios');

const url = "https://go.getblock.io/<ACCESS-TOKEN>/"; 
const headers = { "Content-Type": "application/json" };

const payload = {
  jsonrpc: "2.0",
  id: 1,
  method: "getFeeForMessage",
  params: [
    "AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEBAQAA",
    { "commitment": "processed" }
  ]
};

const fetchTransactionFee = async () => {
  try {
    const response = await axios.post(url, payload, { headers });

    if (response.status === 200 && response.data.result) {
      const fee = response.data.result.value;
      if (fee !== null) {
        console.log("Transaction Fee (lamports):", fee);
      } else {
        console.log("Transaction fee information is not available.");
      }
    } else {
      console.error("Unexpected response:", response.data);
    }
  } catch (error) {
    console.error("getFeeForMessage error:", error.response?.data || error.message);
  }
};

fetchTransactionFee();

Integration with Web3

Integrate the getFeeForMessage API with Solana’s Core API to retrieve real-time fee estimates. By leveraging JSON-RPC parameters and endpoints, developers can ensure accurate transaction fee calculations, helping users make informed decisions before broadcasting transactions.