Promotions
Find the best promotion for a cart
Return the single highest-value eligible promotion for a cart — what to auto-apply at checkout. Galactic Core evaluates every active promotion against the cart server-side and returns the one that saves the customer the most, along with its discount amount.
Send the cart you intend to charge — each line is the product, its quantity, and
the unit price you’re charging. When no promotion applies, promotion is
null and discount is 0.
Marketplace storefronts: pass store_id (the merchant_store_id you
received with the promotion or collection) to evaluate that merchant’s
promotions.
POST
/
v1
/
promotions
/
calculate-best
Find the best promotion for a cart
curl --request POST \
--url https://api.tybritelabs.com/v1/promotions/calculate-best \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"cart": [
{
"product_id": "7d425c0a-50e7-4e39-af79-6f7945f9dfa8",
"quantity": 1,
"price": 349.99
}
]
}
'import requests
url = "https://api.tybritelabs.com/v1/promotions/calculate-best"
payload = { "cart": [
{
"product_id": "7d425c0a-50e7-4e39-af79-6f7945f9dfa8",
"quantity": 1,
"price": 349.99
}
] }
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({
cart: [
{product_id: '7d425c0a-50e7-4e39-af79-6f7945f9dfa8', quantity: 1, price: 349.99}
]
})
};
fetch('https://api.tybritelabs.com/v1/promotions/calculate-best', 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.tybritelabs.com/v1/promotions/calculate-best",
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([
'cart' => [
[
'product_id' => '7d425c0a-50e7-4e39-af79-6f7945f9dfa8',
'quantity' => 1,
'price' => 349.99
]
]
]),
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.tybritelabs.com/v1/promotions/calculate-best"
payload := strings.NewReader("{\n \"cart\": [\n {\n \"product_id\": \"7d425c0a-50e7-4e39-af79-6f7945f9dfa8\",\n \"quantity\": 1,\n \"price\": 349.99\n }\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.tybritelabs.com/v1/promotions/calculate-best")
.header("Authorization", "Bearer <token>")
.header("Content-Type", "application/json")
.body("{\n \"cart\": [\n {\n \"product_id\": \"7d425c0a-50e7-4e39-af79-6f7945f9dfa8\",\n \"quantity\": 1,\n \"price\": 349.99\n }\n ]\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.tybritelabs.com/v1/promotions/calculate-best")
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 \"cart\": [\n {\n \"product_id\": \"7d425c0a-50e7-4e39-af79-6f7945f9dfa8\",\n \"quantity\": 1,\n \"price\": 349.99\n }\n ]\n}"
response = http.request(request)
puts response.read_body{
"promotion": {
"id": "46e746e2-6ef3-4091-ae4e-6bc8d405a1a2",
"name": "Audio + Wearable Bundle",
"type": "bundle"
},
"discount": 100
}{
"error": {
"code": "invalid_request",
"message": "Invalid request parameters",
"details": "The 'email' field is required"
}
}{
"error": {
"code": "unauthorized",
"message": "Missing or invalid Authorization header"
}
}{
"error": {
"code": "forbidden",
"message": "This operation requires a secret key. Publishable keys cover catalogue reads and the actions a shopper takes for themselves."
}
}{
"error": {
"code": "rate_limited",
"message": "Too many requests for this API key. Please slow down and try again shortly.",
"remaining": 0,
"reset": 1706198400
}
}{
"error": {
"code": "server_error",
"message": "An unexpected error occurred"
}
}Authorizations
API Key Authentication
Use your API key in the Authorization header:
Authorization: Bearer tybrite_sk_live_YOUR_KEY
Key Types:
Secret Keys (Server-Side Only):
- Format:
tybrite_sk_live_*(production) ortybrite_sk_test_*(sandbox) - Full read/write access to all endpoints
- ⚠️ NEVER expose in client-side code or public repositories
- Required for: every write a shopper does not make for themselves, authentication, payment verification, AI recommendations
Publishable Keys (Client-Safe):
- Format:
tybrite_pk_live_*(production) ortybrite_pk_test_*(sandbox) - Catalogue reads, plus the actions a shopper takes for themselves
- ✅ Safe for client-side JavaScript, mobile apps, and public code
- Allowed for: browsing products, search, CMS content, pricing queries, cart and wishlist, reviews, storefront events, and the Agent API's quotes, cart drafts and checkout intents
Endpoint-Specific Requirements:
- Authentication endpoints (
/v1/auth/*): Secret key required - Payment verification (
POST /v1/payments/verify): Secret key required - AI Recommendations (
POST /v1/recommendations): Secret key required - Semantic Search (
POST /v1/search): Both key types allowed (read-only operation) - Shopper actions (cart, wishlist, reviews, storefront events, Agent API quotes, cart drafts and checkout intents): Both key types allowed
- All other write operations: Secret key required
- All read operations: Both key types allowed
Using a publishable key for restricted operations returns 403 Forbidden.
Query Parameters
The merchant whose promotions to evaluate. Required for marketplace
storefronts — pass the merchant_store_id you received with the promotion
or collection. Ignored for single-store keys.
Body
application/json
The cart lines to evaluate promotions against. Also accepted under the name items, which behaves identically; send whichever matches your storefront's own cart shape, and cart when both are present.
Show child attributes
Show child attributes
The shopper's country as an ISO 3166-1 alpha-2 code, used to decide whether a market-targeted promotion applies. Optional: when omitted the country is taken from the request's own network origin, so a storefront served through Galactic Core needs to send nothing. Pass it explicitly when your storefront resolves the destination itself, or to preview another market.
Required string length:
2Example:
"US"
The shopper's region or state, for a promotion narrowed within a market. Optional, and taken from the request's origin when omitted.
Example:
"California"
Alias of cart. Send one or the other, not both.
Show child attributes
Show child attributes
⌘I
Find the best promotion for a cart
curl --request POST \
--url https://api.tybritelabs.com/v1/promotions/calculate-best \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"cart": [
{
"product_id": "7d425c0a-50e7-4e39-af79-6f7945f9dfa8",
"quantity": 1,
"price": 349.99
}
]
}
'import requests
url = "https://api.tybritelabs.com/v1/promotions/calculate-best"
payload = { "cart": [
{
"product_id": "7d425c0a-50e7-4e39-af79-6f7945f9dfa8",
"quantity": 1,
"price": 349.99
}
] }
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({
cart: [
{product_id: '7d425c0a-50e7-4e39-af79-6f7945f9dfa8', quantity: 1, price: 349.99}
]
})
};
fetch('https://api.tybritelabs.com/v1/promotions/calculate-best', 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.tybritelabs.com/v1/promotions/calculate-best",
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([
'cart' => [
[
'product_id' => '7d425c0a-50e7-4e39-af79-6f7945f9dfa8',
'quantity' => 1,
'price' => 349.99
]
]
]),
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.tybritelabs.com/v1/promotions/calculate-best"
payload := strings.NewReader("{\n \"cart\": [\n {\n \"product_id\": \"7d425c0a-50e7-4e39-af79-6f7945f9dfa8\",\n \"quantity\": 1,\n \"price\": 349.99\n }\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.tybritelabs.com/v1/promotions/calculate-best")
.header("Authorization", "Bearer <token>")
.header("Content-Type", "application/json")
.body("{\n \"cart\": [\n {\n \"product_id\": \"7d425c0a-50e7-4e39-af79-6f7945f9dfa8\",\n \"quantity\": 1,\n \"price\": 349.99\n }\n ]\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.tybritelabs.com/v1/promotions/calculate-best")
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 \"cart\": [\n {\n \"product_id\": \"7d425c0a-50e7-4e39-af79-6f7945f9dfa8\",\n \"quantity\": 1,\n \"price\": 349.99\n }\n ]\n}"
response = http.request(request)
puts response.read_body{
"promotion": {
"id": "46e746e2-6ef3-4091-ae4e-6bc8d405a1a2",
"name": "Audio + Wearable Bundle",
"type": "bundle"
},
"discount": 100
}{
"error": {
"code": "invalid_request",
"message": "Invalid request parameters",
"details": "The 'email' field is required"
}
}{
"error": {
"code": "unauthorized",
"message": "Missing or invalid Authorization header"
}
}{
"error": {
"code": "forbidden",
"message": "This operation requires a secret key. Publishable keys cover catalogue reads and the actions a shopper takes for themselves."
}
}{
"error": {
"code": "rate_limited",
"message": "Too many requests for this API key. Please slow down and try again shortly.",
"remaining": 0,
"reset": 1706198400
}
}{
"error": {
"code": "server_error",
"message": "An unexpected error occurred"
}
}