> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ton.org/llms.txt
> Use this file to discover all available pages before exploring further.
## Submitting Feedback
If you encounter incorrect, outdated, or confusing documentation on this page, submit feedback:
POST https://docs.ton.org/feedback
```json
{
"path": "/ecosystem/api/toncenter/v2/send/estimate-fee",
"feedback": "Description of the issue"
}
```
Only submit feedback when you have something specific and actionable to report.
# 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 when estimating before signing. Returns a breakdown of storage, gas, and forwarding fees.
## OpenAPI
````yaml post /api/v2/estimateFee
openapi: 3.1.1
info:
title: TON HTTP API C++
description: >
This API enables HTTP access to TON blockchain - getting accounts and
wallets information, looking up blocks and transactions, sending messages to
the blockchain, calling get methods of smart contracts, and more.
In addition to REST API, all methods are available through a JSON-RPC
endpoint with `method` equal to method name and `params` passed as a
dictionary.
The response contains a JSON object, which always has a boolean field `ok`
and either `error` or `result`. If `ok` equals true, the request was
successful and the result of the query can be found in the `result` field.
In case of an unsuccessful request, `ok` equals false and the error is
explained in the `error`.
API Key should be sent either as `api_key` query parameter or `X-API-Key`
header
version: 2.1.1
servers:
- url: https://toncenter.com
description: TON Mainnet
- url: https://testnet.toncenter.com
description: TON Testnet
security: []
tags:
- name: Accounts
description: Information about accounts
- name: Transactions
description: Fetching and locating transactions
- name: Blocks
description: Information about blocks
- name: Run method
description: Run get-method of smart contracts
- name: Send
description: Send data to blockchain
- name: Utils
description: Some useful methods
- name: Configuration
description: Information about blockchain config
- name: RPC
description: JSON-RPC and POST endpoints
paths:
/api/v2/estimateFee:
post:
tags:
- Send
summary: Estimate fee
description: >-
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 when estimating
before signing. Returns a breakdown of storage, gas, and forwarding
fees.
operationId: estimateFee_post
requestBody:
content:
application/json:
schema:
$ref: '#/components/schemas/EstimateFeeRequest'
required: true
responses:
'200':
description: >-
Returns the estimated fees (gas, storage, forwarding) for the
specified message.
content:
application/json:
schema:
$ref: '#/components/schemas/EstimateFeeResponse'
'401':
$ref: '#/components/responses/401'
'403':
$ref: '#/components/responses/403'
'422':
$ref: '#/components/responses/422_run'
'429':
$ref: '#/components/responses/429'
'500':
$ref: '#/components/responses/500_execution'
'504':
$ref: '#/components/responses/504'
security:
- APIKeyHeader: []
- APIKeyQuery: []
components:
schemas:
EstimateFeeRequest:
type: object
additionalProperties: false
required:
- address
- body
properties:
address:
$ref: '#/components/schemas/TonAddr'
body:
$ref: '#/components/schemas/Bytes'
description: Message body in BoC format, base64 encoded.
init_code:
$ref: '#/components/schemas/Bytes'
description: >-
Contract code for deployment messages, BoC format, base64 encoded.
Omit for regular transfers.
init_data:
$ref: '#/components/schemas/Bytes'
description: >-
Initial contract storage for deployment, BoC format, base64 encoded.
Omit for regular transfers.
ignore_chksig:
type: boolean
default: true
description: >-
Set to `true` to skip signature verification during fee estimation;
otherwise `false`. Useful when a real signature is not yet
available.
description: >-
Request to estimate transaction fees. Include the target address,
message body, and optionally init code/data for contract deployment.
EstimateFeeResponse:
type: object
additionalProperties: false
required:
- ok
- result
properties:
ok:
type: boolean
default: true
description: >-
Returns `true` if the request succeeded; otherwise `false`. See the
`error` field for details.
result:
$ref: '#/components/schemas/QueryFees'
description: Response data. Present only when `ok` is `true`.
'@extra':
type: string
description: >-
Optional request ID that can be passed in the request and received
back in the response. Useful for matching async responses.
TonAddr:
type: string
x-usrv-cpp-type: ton_http::types::ton_addr
description: >-
Account address in [raw](/foundations/addresses/formats#raw-format)
format (e.g., `0:ca6e321c...`) or
[user-friendly](/foundations/addresses/formats#user-friendly-format)
format (e.g., `EQDKbjIcfM...`). All formats are automatically detected.
Bytes:
type: string
x-usrv-cpp-type: ton_http::types::bytes
description: >-
Binary data encoded as base64. Used for serialized cells (BoC format),
message bodies, and smart contract code/data.
QueryFees:
type: object
additionalProperties: false
required:
- '@type'
- source_fees
- destination_fees
properties:
'@type':
type: string
enum:
- query.fees
default: query.fees
description: >-
TonLib type identifier for fee estimation results. Refer to the
[TonLib type reference](/ecosystem/api/toncenter/v2-tonlib-types)
for a full list.
source_fees:
$ref: '#/components/schemas/Fees'
description: Fees charged on the sending account.
destination_fees:
type: array
items:
$ref: '#/components/schemas/Fees'
description: >-
Array of fee breakdowns charged on the receiving account(s). One
entry per destination in multi-hop transactions.
description: >-
Estimated fees for a transaction. Shows the breakdown between storage
fees (for contract state), gas fees (for computation), and forward fees
(for message delivery).
Fees:
type: object
additionalProperties: false
required:
- '@type'
- in_fwd_fee
- storage_fee
- gas_fee
- fwd_fee
properties:
'@type':
type: string
enum:
- fees
default: fees
description: >-
TonLib type identifier for fee breakdown objects. Refer to the
[TonLib type reference](/ecosystem/api/toncenter/v2-tonlib-types)
for a full list.
in_fwd_fee:
type: integer
format: int64
description: Fee for importing this inbound message, in nanotons.
storage_fee:
type: integer
format: int64
description: >-
Storage fee charged for keeping the contract state on-chain, in
nanotons.
gas_fee:
type: integer
format: int64
description: Computation gas fee for executing contract code, in nanotons.
fwd_fee:
type: integer
format: int64
description: >-
Fee for forwarding outbound messages created by this transaction, in
nanotons.
responses:
'401':
description: API key does not exist. Check for typos or generate a new key.
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 401
description: HTTP status code `401`.
error:
type: string
enum:
- API key does not exist
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 401
error: API key does not exist
'403':
description: >-
API key is not allowed for this network (e.g. testnet key used on
mainnet).
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 403
description: HTTP status code `403`.
error:
type: string
enum:
- Network not allowed
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 403
error: Network not allowed
'429':
description: >-
Rate limit exceeded. Back off and retry, or use an API key for higher
limits.
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 429
description: HTTP status code `429`.
error:
type: string
enum:
- Ratelimit exceeded
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 429
error: Ratelimit exceeded
'504':
description: Timeout waiting for liteserver response.
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 504
description: HTTP status code `504`.
error:
type: string
enum:
- LITE_SERVER_NETWORK timeout
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 504
error: LITE_SERVER_NETWORK timeout
422_run:
description: Invalid get method or stack parameters.
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 422
description: HTTP status code `422`.
error:
type: string
enum:
- Stack should be array
- 'Invalid stack format: array expected'
- >-
Invalid stack entry format: array of exact 2 elements
expected
- Expected string as first element in stack entry
- Wrong type of number in stack entry
- Invalid tvm.Cell, base64 string expected
- Invalid tvm.Slice, base64 string expected
- Empty tvm.Cell
- Empty tvm.Slice
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 422
error: Stack should be array
500_execution:
description: Get method or simulation execution failed.
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 500
description: HTTP status code `500`.
error:
type: string
enum:
- Exit code != 0
- Stack size < 5
- 'Failed to parse int: '
- stackEntryNumber expected
- stackEntryCell expected at position
- stackEntryCell or stackEntrySlice expected
- addr_ext is not supported
- addr_var is not supported
- anycast is not supported
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 500
error: Exit code != 0
securitySchemes:
APIKeyHeader:
type: apiKey
in: header
name: X-API-Key
description: >-
API key header of the form `X-API-Key: `, where `` is the
API key. Requests without a key are limited to 1 RPS. Refer to the
[authentication guide](/ecosystem/api/toncenter/v2-authentication) for
details.
APIKeyQuery:
type: apiKey
in: query
name: api_key
description: >-
API key query parameter of the form `?api_key=`, where ``
is the API key. Equivalent to the header method. Refer to the
[authentication guide](/ecosystem/api/toncenter/v2-authentication) for
details.
````