Create a purchase transaction
Charges the payment method immediately (authorize and capture in a single
step) for amount_cents on the gateway. Creates a purchase transaction and
returns it with 201. Pass an Idempotency-Key header to make retries safe —
a replay returns the original result with X-Idempotent-Replayed: true.
Returns 404 when the gateway is not found, 409 when a request with the same
key is still in flight, and 422 when the request fails validation.
curl --request POST \
--url https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"transaction": {
"amount_cents": 4999,
"currency_code": "USD",
"payment_method_id": "pm_9f8e7d6c"
}
}
'import requests
url = "https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase"
payload = { "transaction": {
"amount_cents": 4999,
"currency_code": "USD",
"payment_method_id": "pm_9f8e7d6c"
} }
headers = {
"Authorization": "Bearer <token>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
body: JSON.stringify({
transaction: {amount_cents: 4999, currency_code: 'USD', payment_method_id: 'pm_9f8e7d6c'}
})
};
fetch('https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'transaction' => [
'amount_cents' => 4999,
'currency_code' => 'USD',
'payment_method_id' => 'pm_9f8e7d6c'
]
]),
CURLOPT_HTTPHEADER => [
"Authorization: Bearer <token>",
"Content-Type: application/json"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase"
payload := strings.NewReader("{\n \"transaction\": {\n \"amount_cents\": 4999,\n \"currency_code\": \"USD\",\n \"payment_method_id\": \"pm_9f8e7d6c\"\n }\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("Authorization", "Bearer <token>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase")
.header("Authorization", "Bearer <token>")
.header("Content-Type", "application/json")
.body("{\n \"transaction\": {\n \"amount_cents\": 4999,\n \"currency_code\": \"USD\",\n \"payment_method_id\": \"pm_9f8e7d6c\"\n }\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"transaction\": {\n \"amount_cents\": 4999,\n \"currency_code\": \"USD\",\n \"payment_method_id\": \"pm_9f8e7d6c\"\n }\n}"
response = http.request(request)
puts response.read_body{
"data": {
"id": "<string>",
"amount_cents": 123,
"currency_code": "<string>",
"processing_fee_cents": 123,
"credited_amount_cents": 123,
"retain_on_success": true,
"metadata": {},
"created_at": "2023-11-07T05:31:56Z",
"updated_at": "2023-11-07T05:31:56Z",
"gateway_id": "<string>",
"payment_method_id": "<string>",
"card_network": "<string>",
"parent_transaction_id": "<string>",
"payment_source": "<string>",
"gateway_transaction_id": "<string>",
"reference_token": "<string>",
"description": "<string>",
"platform_fee_cents": 123
},
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"message": "<string>",
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
},
"status": "<string>"
}{
"message": "<string>",
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": "error",
"message": "<string>",
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": "error",
"message": "<string>",
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": "error",
"message": "<string>",
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
}
}Authorizations
API key (fp_live_/fp_test_) or JWT bearer token
Headers
Optional client-generated key (UUID recommended) used to deduplicate
retries. The first request with a given key executes normally; a retry
with the same key replays that first response with
X-Idempotent-Replayed: true for up to 24 hours. A concurrent retry
while the first request is still in flight returns 409.
The response cache is keyed on the authenticated merchant and this key ONLY — not on the operation, path, or request body. Use a fresh, unique key per logical request: reusing one key across different operations (for example a purchase and then a capture) replays the first operation's cached status and body instead of performing the second.
255Path Parameters
Gateway slug
Body
Show child attributes
Show child attributes
curl --request POST \
--url https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"transaction": {
"amount_cents": 4999,
"currency_code": "USD",
"payment_method_id": "pm_9f8e7d6c"
}
}
'import requests
url = "https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase"
payload = { "transaction": {
"amount_cents": 4999,
"currency_code": "USD",
"payment_method_id": "pm_9f8e7d6c"
} }
headers = {
"Authorization": "Bearer <token>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
body: JSON.stringify({
transaction: {amount_cents: 4999, currency_code: 'USD', payment_method_id: 'pm_9f8e7d6c'}
})
};
fetch('https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'transaction' => [
'amount_cents' => 4999,
'currency_code' => 'USD',
'payment_method_id' => 'pm_9f8e7d6c'
]
]),
CURLOPT_HTTPHEADER => [
"Authorization: Bearer <token>",
"Content-Type: application/json"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase"
payload := strings.NewReader("{\n \"transaction\": {\n \"amount_cents\": 4999,\n \"currency_code\": \"USD\",\n \"payment_method_id\": \"pm_9f8e7d6c\"\n }\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("Authorization", "Bearer <token>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase")
.header("Authorization", "Bearer <token>")
.header("Content-Type", "application/json")
.body("{\n \"transaction\": {\n \"amount_cents\": 4999,\n \"currency_code\": \"USD\",\n \"payment_method_id\": \"pm_9f8e7d6c\"\n }\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.fluid.app/api/payment/v2026-04/gateways/{id}/purchase")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"transaction\": {\n \"amount_cents\": 4999,\n \"currency_code\": \"USD\",\n \"payment_method_id\": \"pm_9f8e7d6c\"\n }\n}"
response = http.request(request)
puts response.read_body{
"data": {
"id": "<string>",
"amount_cents": 123,
"currency_code": "<string>",
"processing_fee_cents": 123,
"credited_amount_cents": 123,
"retain_on_success": true,
"metadata": {},
"created_at": "2023-11-07T05:31:56Z",
"updated_at": "2023-11-07T05:31:56Z",
"gateway_id": "<string>",
"payment_method_id": "<string>",
"card_network": "<string>",
"parent_transaction_id": "<string>",
"payment_source": "<string>",
"gateway_transaction_id": "<string>",
"reference_token": "<string>",
"description": "<string>",
"platform_fee_cents": 123
},
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"message": "<string>",
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
},
"status": "<string>"
}{
"message": "<string>",
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": "error",
"message": "<string>",
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": "error",
"message": "<string>",
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": "error",
"message": "<string>",
"meta": {
"request_id": "<string>",
"timestamp": "2023-11-07T05:31:56Z"
}
}