> ## Documentation Index
> Fetch the complete documentation index at: https://developers.paxoslabs.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Calculate withdrawal fee
> Calculates the withdrawal fee the user would be charged for a given offer amount and want asset.
## OpenAPI
````yaml /v1.0.0/api-reference/openapi.yml get /v2/amplify/calculateWithdrawalFee
openapi: 3.0.0
info:
title: Paxos Labs API
description: >
Paxos Labs API V2.
---
# API overview
This document describes shared behavior and conventions for the Paxos Labs
API (REST and GraphQL).
Health check
A **health** endpoint is available for orchestrators (GitHub Actions, etc).
| Item |
Details
|
| ------------ |
---------------------------------------------------------------------------------------
|
| **Path** | `GET /health` (no version prefix; no API key or rate limit
applied). |
| **Response** | `200` with Terminus-style JSON when healthy; `503` when
unhealthy (e.g. database down). |
**Docker / healthcheck:** If your healthcheck uses `curl` (e.g. `curl -f
http://localhost:3000/health`), ensure your image has curl installed. Base
images like `node:bullseye-slim` or `node:alpine` do not—install it (e.g.
`RUN apk add --no-cache curl` for Alpine).
GraphQL endpoint
A **GraphQL** API is available in addition to REST. Use it to query address
book and vault data with a single request and flexible field selection.
| Item |
Details |
| ---------------------------- |
-------------------------------------------------------------------- |
| **Altair (interactive IDE)** |
[https://api.paxoslabs.com/altair](https://api.paxoslabs.com/altair) |
| **GraphQL endpoint** | Same base URL with path `/graphql` for
POST. |
| **Authentication** | Same as REST: send `x-api-key`
header. |
Open the Altair link in a browser to explore the schema and run queries.
Filter query parameter syntax
List endpoints that support a `filter` query parameter use a single string
with **keys**, **operators**, and **combinators**. This keeps the number of
query params small (AIP-160 style) while allowing flexible filtering.
Operators
| Operator | Meaning | Example |
| -------- | ---------- | ------------------ |
| `=` | Equals | `chainId=1` |
| `!=` | Not equals | `status!=REFUNDED` |
Combinators
| Combinator | Meaning |
Example |
| ---------- | -------------------------------------------- |
------------------------------- |
| `AND` | All conditions must match (case-insensitive) | `chainId=1 AND
name="Treasury"` |
| `OR` | Any condition may match (case-insensitive) | `chainId=1 OR
chainId=137` |
Value formatting
| Type | Use case |
Example |
| -------- | ----------------------------------------- |
------------------------- |
| Unquoted | Numbers, booleans, single-token values | `chainId=1`,
`valid=true` |
| Quoted | Strings with spaces or special characters | `name="Treasury
Wallet"` |
| Escape | Literal quote inside a quoted string |
`\"` |
Allowed **keys** and **value types** (number, hex address, string, etc.) are
defined per endpoint in the API docs and validated by the server.
Possible combinations (examples)
| Category |
Example |
| --------------------- |
--------------------------------------------------- |
| Single condition |
`chainId=1` |
| Single condition |
`status!=REFUNDED` |
| AND | `chainId=1 AND
name="Treasury"` |
| AND | `vaultAddress=0x123... AND
chainId=1` |
| OR | `chainId=1 OR
chainId=137` |
| OR | `status=PENDING OR
status=COMPLETE` |
| Mixed AND and OR | `chainId=1 AND (status=PENDING OR
status=COMPLETE)` |
| Equals and not-equals | `chainId=1 AND
status!=REFUNDED` |
| Equals and not-equals |
`name!=""` |
Mixed AND and OR: AND has higher precedence; use parentheses for grouping.
Without grouping, evaluation is left-to-right per implementation.
Implementation note
| Item |
Details |
| --------- |
------------------------------------------------------------------------- |
| Location |
`src/common/utils/filter.util.ts` |
| Supported | `=`, `!=`, `AND`,
`OR` |
| Errors | Invalid keys or value types return `400` with the standard
error envelope |
version: '2.0'
contact: {}
servers:
- url: https://api.paxoslabs.com/
description: Production
security: []
tags: []
paths:
/v2/amplify/calculateWithdrawalFee:
get:
tags:
- Withdraw
summary: Calculate withdrawal fee
description: >-
Calculates the withdrawal fee the user would be charged for a given
offer amount and want asset.
operationId: calculateFee
parameters:
- name: offerAmount
required: true
in: query
description: Share amount to withdraw (base units decimal string)
schema:
type: string
example: '1000000000000000000'
- name: wantAsset
required: true
in: query
description: ERC-20 token address the user wants to receive
schema:
example: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48'
type: string
- name: vaultAddress
required: true
in: query
description: BoringVault contract address (0x + 40 hex chars)
schema:
example: '0xbbbb000000000000000000000000000000000001'
type: string
- name: chainId
required: true
in: query
description: EVM chain ID
schema:
type: number
example: 1
responses:
'200':
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/CalculateWithdrawalFeeResponseDto'
'400':
description: Invalid request parameters
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponseDto'
'404':
description: Vault not found
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponseDto'
'503':
description: RPC or indexer unavailable
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponseDto'
security:
- api-key: []
components:
schemas:
CalculateWithdrawalFeeResponseDto:
type: object
properties:
feeAmount:
type: string
description: Fee amount charged for the given offer and want asset.
example: '0.05'
offerFeePercentage:
description: Offer fee percentage in bps.
allOf:
- $ref: '#/components/schemas/FeeDto'
flatFee:
type: string
description: >-
Flat fee charged on every withdrawal for the given offer and want
asset. Denominated in the want asset.
example: '1.05'
required:
- feeAmount
- offerFeePercentage
- flatFee
ErrorResponseDto:
type: object
properties:
error:
description: Error object containing details
allOf:
- $ref: '#/components/schemas/ErrorObjectDto'
required:
- error
FeeDto:
type: object
properties:
bps:
type: number
description: Fee in basis points (integer). 25 = 0.25%.
example: 25
percentage:
type: string
description: 'Human-readable percentage (4 decimals). Example: "0.2500" = 0.25%.'
example: '0.2500'
required:
- bps
- percentage
ErrorObjectDto:
type: object
properties:
code:
type: number
description: HTTP status code
example: 400
message:
type: string
description: Human-readable error message
example: Invalid filter syntax.
status:
type: string
description: Error status enum value
enum:
- UNKNOWN
- INVALID_ARGUMENT
- NOT_FOUND
- PERMISSION_DENIED
- UNAUTHENTICATED
- RESOURCE_EXHAUSTED
- INTERNAL
- METHOD_NOT_ALLOWED
example: INVALID_ARGUMENT
details:
description: Additional error details
type: array
items:
$ref: '#/components/schemas/ErrorDetailDto'
required:
- code
- message
- status
ErrorDetailDto:
type: object
properties:
'@type':
type: string
description: Type URL identifying the error detail schema
example: type.paxoslabs.dev/errors/BadRequest
fieldViolations:
description: Field-level violations for validation errors
type: array
items:
$ref: '#/components/schemas/FieldViolationDto'
required:
- '@type'
FieldViolationDto:
type: object
properties:
field:
type: string
description: The field that caused the violation
example: filter
description:
type: string
description: Description of the violation
example: vaultAddress 0x0x is an invalid hex address.
required:
- field
- description
securitySchemes:
api-key:
type: apiKey
in: header
name: x-api-key
description: 'API key in format: pxl__'
````