Estimate fee

Calculates the fees required to send a message. Provide the destination address and message body. For new contract deployments, also include init_code and init_data. Set ignore_chksig to true since you’re estimating before signing. Returns a breakdown of storage, gas, and forwarding fees.

POST /api/v2/estimateFee

Estimate fee

cURL

curl --request POST \
  --url https://toncenter.com/api/v2/estimateFee \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "address": "<string>",
  "body": "<string>",
  "init_code": "<string>",
  "init_data": "<string>",
  "ignore_chksig": true
}
'

200

{
  "ok": true,
  "result": {
    "@type": "query.fees",
    "source_fees": {
      "@type": "fees",
      "in_fwd_fee": 123,
      "storage_fee": 123,
      "gas_fee": 123,
      "fwd_fee": 123
    },
    "destination_fees": [
      {
        "@type": "fees",
        "in_fwd_fee": 123,
        "storage_fee": 123,
        "gas_fee": 123,
        "fwd_fee": 123
      }
    ]
  },
  "@extra": "<string>"
}

Authorizations

APIKeyHeaderAPIKeyQuery

X-API-Key · string · header · required

API key header of the form X-API-Key: <token>, where <token> is your API key. Requests without a key are limited to 1 RPS. More info here.

Body

application/json

Request to estimate transaction fees. Include the target address, message body, and optionally init code/data for contract deployment.

address · string · required

Account address in raw format (e.g., 0:ca6e321c...) or user-friendly format (e.g., EQDKbjIcfM...). All formats are automatically detected.

body · string · required

Message body in BOC format, base64 encoded.

init_code · string

Contract code for deployment messages, BOC format, base64 encoded. Omit for regular transfers.

init_data · string

Initial contract storage for deployment, BOC format, base64 encoded. Omit for regular transfers.

ignore_chksig · boolean · default: true

Set to true to skip signature verification during fee estimation; otherwise false. Useful when you don't have a real signature yet.

Response

200

application/json

Returns the estimated fees (gas, storage, forwarding) for the specified message.

ok · boolean · default: true · required

Returns true if the request succeeded; otherwise false. See the error field for details.

result · object · required

Response data. Present only when ok is true.

Show child attributes

@extra · string

Optional request ID that you can pass in the request and receive back in the response. Useful for matching async responses.