FOREIGN EXCHANGE

Convert with a locked rate

POSThttps://production.dutchapi.co/v1/fx/convert

Executes a conversion at the rate locked by POST /v1/fx/quote. A quote can be used once.

🔒Send the project API key as a Bearer token and your Business ID with this call.

Requires an Idempotency-Key header.

Body Params

quote_idstringrequired

The id from POST /v1/fx/quote.

Responses

{
  "id": "fx_92ac10",
  "object": "exchange",
  "kind": "conversion",
  "status": "completed",
  "amount": 100,
  "currency": "USD",
  "fee": 0,
  "to": {
    "currency": "XAF",
    "amount": 59040,
    "rate": 590.4
  }
}

{
  "error": "idempotency_key_required",
  "message": "Send an Idempotency-Key header."
}

Errors

Status	error	Meaning
400	`idempotency_key_required`	Send an Idempotency-Key header.
400	`quote_id_required`	Send the quote_id.
409	`quote_expired_or_used`	Get a new quote.
402	`insufficient_funds`	The wallet balance is too low.
423	`money_movement_paused`	The kill switch is on.
422	`exchange_rejected`	The partner rejected the conversion.

Updated 2026

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Language

CredentialsBearer

curl --request POST --url "https://production.dutchapi.co/v1/fx/convert" \
  --header "Authorization: Bearer $DUTCH_PROJECT_KEY" \
  --header "X-Business-Id: $DUTCH_BUSINESS_ID" \
  --header "Idempotency-Key: create-fx-conversion-0001" \
  --header "Content-Type: application/json" \
  --data '{"quote_id":"fxq_5a1c"}'

const res = await fetch("https://production.dutchapi.co/v1/fx/convert", {
  method: "POST",
  headers: {
    "Authorization": "Bearer " + process.env.DUTCH_PROJECT_KEY,
    "X-Business-Id": process.env.DUTCH_BUSINESS_ID,
    "Idempotency-Key": "create-fx-conversion-0001",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({"quote_id": "fxq_5a1c"})
});
console.log(await res.json());

require "net/http"
require "json"

uri = URI("https://production.dutchapi.co/v1/fx/convert")
req = Net::HTTP::Post.new(uri)
req["Authorization"] = "Bearer #{ENV.fetch('DUTCH_PROJECT_KEY')}"
req["X-Business-Id"] = ENV.fetch("DUTCH_BUSINESS_ID")
req["Idempotency-Key"] = "create-fx-conversion-0001"
req["Content-Type"] = "application/json"
req.body = "{\"quote_id\":\"fxq_5a1c\"}"
res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |http| http.request(req) }
puts res.body

<?php
$ch = curl_init("https://production.dutchapi.co/v1/fx/convert");
curl_setopt_array($ch, [
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_HTTPHEADER => ["Authorization: Bearer " . getenv("DUTCH_PROJECT_KEY"),
    "X-Business-Id: " . getenv("DUTCH_BUSINESS_ID"),
    "Idempotency-Key: create-fx-conversion-0001",
    "Content-Type: application/json"],
  CURLOPT_POSTFIELDS => '{"quote_id":"fxq_5a1c"}',
]);
echo curl_exec($ch);

import os, requests, json

res = requests.request(
    "POST",
    "https://production.dutchapi.co/v1/fx/convert",
    headers={
        "Authorization": "Bearer " + os.environ["DUTCH_PROJECT_KEY"],
        "X-Business-Id": os.environ["DUTCH_BUSINESS_ID"],
        "Idempotency-Key": "create-fx-conversion-0001",
    },
    json=json.loads("{\"quote_id\":\"fxq_5a1c\"}")
)
print(res.json())

Response

Click `Show example` to see an example response. Nothing is sent from this page: endpoints are live, so run real requests from your own code with small amounts.