> ## Documentation Index
> Fetch the complete documentation index at: https://docs.velumx.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Estimate Fee

> Calculate the required fee in a specific SIP-010 token for a transaction intent.



## OpenAPI

````yaml POST /estimate
openapi: 3.1.0
info:
  title: VelumX Relayer API
  description: >-
    Infrastructure-grade gasless transaction sponsorship for the Stacks
    ecosystem.
  version: 1.0.0
  license:
    name: MIT
servers:
  - url: https://api.velumx.xyz/api/v1
    description: Production Relayer
security:
  - ApiKeyAuth: []
paths:
  /estimate:
    post:
      summary: Estimate Sponsorship Fee
      description: >-
        Calculate the required fee in a specific SIP-010 token for a transaction
        intent.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                intent:
                  type: object
                  properties:
                    feeToken:
                      type: string
                      description: Contract principal of the gas token
                    estimatedGas:
                      type: integer
                      default: 150000
                  required:
                    - feeToken
                network:
                  type: string
                  enum:
                    - mainnet
                    - testnet
                  default: mainnet
      responses:
        '200':
          description: Fee estimation result
          content:
            application/json:
              schema:
                type: object
                properties:
                  maxFee:
                    type: string
                  maxFeeUsd:
                    type: string
                  feeToken:
                    type: string
                  relayerAddress:
                    type: string
                  paymasterAddress:
                    type: string
                  registryAddress:
                    type: string
components:
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: x-api-key

````