Use the Purchase Limits API to retrieve the minimum and maximum transaction amounts supported for buy and sell transactions.

You should retrieve the latest limits before creating a transaction. Limits may vary by fiat currency or crypto asset.

Authentication

All requests must include your private API key in the x-private-key header.

x-private-key: YOUR_PRIVATE_KEY

Keep your private key secure. Do not expose it in client-side applications or public repositories.

Base URL

https://ramp-be.quidax.io/api/v1/merchants

Retrieve Buy Limits

Retrieves the minimum and maximum fiat amount a customer can use to purchase cryptocurrency.

GET /purchase_limits/buy

Request

Pass the fiat currency using the currency_symbol query parameter.

Supported currencies

Currency	Description
`ngn`	Nigerian naira
`ghs`	Ghanaian cedi

Example request

curl --request GET \
  --url "https://ramp-be.quidax.io/api/v1/merchants/purchase_limits/buy?currency_symbol=ngn" \
  --header "accept: application/json" \
  --header "x-private-key: YOUR_PRIVATE_KEY"

Successful response

{
  "status": "ok",
  "message": "Fiat currency limit retrieved",
  "data": {
    "code": "ngn",
    "min_value": "2000.0",
    "max_value": "2000000.0",
    "interval": "daily"
  }
}

Response fields

Field	Description
`status`	Indicates whether the request was successful. A successful request returns `ok`.
`message`	A human-readable description of the result.
`data`	Contains the purchase limit details.
`data.code`	The fiat currency the limits apply to.
`data.min_value`	The minimum fiat amount allowed for a buy transaction. The value is returned as a string.
`data.max_value`	The maximum fiat amount allowed within the stated interval. The value is returned as a string.
`data.interval`	The period used to apply the limit. For example, `daily` means the maximum applies per day.

In this example, the customer can create an NGN buy transaction from 2,000 NGN up to a daily maximum of 2,000,000 NGN.

Retrieve Sell Limits

Retrieves the minimum and maximum amount of a crypto asset that a customer can sell.

GET /purchase_limits/sell

Request

Pass the crypto asset using the token_symbol query parameter.

Supported assets

Asset	Description
`usdt`	Tether
`usdc`	USD Coin
`xaut`	Tether Gold
`usat`	USAT

Example request

curl --request GET \
  --url "https://ramp-be.quidax.io/api/v1/merchants/purchase_limits/sell?token_symbol=usdt" \
  --header "accept: application/json" \
  --header "x-private-key: YOUR_PRIVATE_KEY"

Successful response

{
  "status": "ok",
  "message": "Crypto sell limit retrieved",
  "data": {
    "code": "usdt",
    "min_value": "2.0",
    "max_value": "3000.0",
    "interval": "daily"
  }
}

Response fields

Field	Description
`status`	Indicates whether the request was successful. A successful request returns `ok`.
`message`	A human-readable description of the result.
`data`	Contains the sell limit details.
`data.code`	The crypto asset the limits apply to.
`data.min_value`	The minimum amount of the crypto asset that can be sold. The value is returned as a string.
`data.max_value`	The maximum amount of the crypto asset that can be sold within the stated interval. The value is returned as a string.
`data.interval`	The period used to apply the limit. For example, `daily` means the maximum applies per day.

In this example, the customer can sell from 2 USDT up to a daily maximum of 3,000 USDT.

Error responses

Invalid fiat currency

This error is returned when currency_symbol is missing or contains an unsupported fiat currency.

{
  "status": "bad_request",
  "message": "Invalid fiat currency",
  "data": null
}

Use one of the supported fiat currencies:

ngn
ghs

Invalid crypto asset

This error is returned when token_symbol is missing or contains an unsupported crypto asset.

{
  "status": "bad_request",
  "message": "Invalid crypto currency",
  "data": null
}

Use one of the supported crypto assets:

usdt
usdc
xaut
usat

Invalid private key

This error is returned when the x-private-key header is missing or invalid.

{
  "status": "forbidden",
  "message": "Invalid private key",
  "data": null
}

Confirm that you are using the correct private key and that it is passed in the request header.

Recommended integration flow

Before initiating a buy or sell transaction:

Retrieve the limit for the selected fiat currency or crypto asset.
Convert min_value and max_value to a decimal type before comparing amounts.
Confirm that the customer’s amount is greater than or equal to min_value.
Confirm that the amount does not exceed max_value for the stated interval.
Show a clear validation message when the amount is outside the supported range.

Do not hard-code purchase limits. Retrieve them from the API so your integration always uses the latest available limits.