getFeeForMessage

Returns the fee that the network will charge for a particular message. The message must be base-64 encoded and is typically obtained from a constructed transaction. This is the recommended way to estimate transaction costs on Solana, replacing the deprecated getFeeCalculatorForBlockhash. It accounts for the number of signatures, compute budget instructions, and priority fees.

Parameters

#	Type	Required	Description
1	`string`	Yes	Base-64 encoded serialized transaction message
2	`object`	No	Configuration object

Configuration object fields:

Field	Type	Description
`commitment`	`string`	Commitment level: `processed`, `confirmed`, or `finalized`
`minContextSlot`	`number`	Minimum slot at which the request can be evaluated

Response

Returns an RpcResponse object:

Field	Type	Description
`context.slot`	`u64`	The slot at which the fee was evaluated
`value`	`u64	null`

Code Examples

cURL

1curl http://[IP_ADDRESS]:[PORT] -X POST -H "Content-Type: application/json" -d '{
2  "jsonrpc": "2.0",
3  "id": 1,
4  "method": "getFeeForMessage",
5  "params": [
6    "AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEBAQAA",
7    { "commitment": "confirmed" }
8  ]
9}'

TypeScript

1const response = await fetch("http://[IP_ADDRESS]:[PORT]", {
2  method: "POST",
3  headers: { "Content-Type": "application/json" },
4  body: JSON.stringify({
5    jsonrpc: "2.0",
6    id: 1,
7    method: "getFeeForMessage",
8    params: [
9      "AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEBAQAA",
10      { commitment: "confirmed" }
11    ]
12  }),
13});
14const { result } = await response.json();
15console.log("Fee:", result.value, "lamports");

Python

1import requests
2
3response = requests.post("http://[IP_ADDRESS]:[PORT]", json={
4    "jsonrpc": "2.0",
5    "id": 1,
6    "method": "getFeeForMessage",
7    "params": [
8        "AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEBAQAA",
9        {"commitment": "confirmed"}
10    ]
11})
12result = response.json()["result"]
13print(f"Fee: {result['value']} lamports")

Rust

1use reqwest::Client;
2use serde_json::json;
3
4#[tokio::main]
5async fn main() -> Result<(), Box<dyn std::error::Error>> {
6    let client = Client::new();
7    let res = client.post("http://[IP_ADDRESS]:[PORT]")
8        .json(&json!({
9            "jsonrpc": "2.0",
10            "id": 1,
11            "method": "getFeeForMessage",
12            "params": [
13                "AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEBAQAA",
14                {"commitment": "confirmed"}
15            ]
16        }))
17        .send().await?
18        .text().await?;
19    println!("{}", res);
20    Ok(())
21}

Example Response

1{
2  "jsonrpc": "2.0",
3  "result": {
4    "context": { "slot": 123456789 },
5    "value": 5000
6  },
7  "id": 1
8}