curl --request POST \
  --url https://synthesis.trade/api/v1/markets/orderbooks \
  --header 'Content-Type: application/json' \
  --data '
[
  "21742633143463906290569050155826241533067272736897614950488156847949938836455",
  "KXBTC-25-T100000"
]
'

import requests

url = "https://synthesis.trade/api/v1/markets/orderbooks"

payload = ["21742633143463906290569050155826241533067272736897614950488156847949938836455", "KXBTC-25-T100000"]
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify([
    '21742633143463906290569050155826241533067272736897614950488156847949938836455',
    'KXBTC-25-T100000'
  ])
};

fetch('https://synthesis.trade/api/v1/markets/orderbooks', 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://synthesis.trade/api/v1/markets/orderbooks",
  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([
    '21742633143463906290569050155826241533067272736897614950488156847949938836455',
    'KXBTC-25-T100000'
  ]),
  CURLOPT_HTTPHEADER => [
    "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://synthesis.trade/api/v1/markets/orderbooks"

	payload := strings.NewReader("[\n  \"21742633143463906290569050155826241533067272736897614950488156847949938836455\",\n  \"KXBTC-25-T100000\"\n]")

	req, _ := http.NewRequest("POST", url, payload)

	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://synthesis.trade/api/v1/markets/orderbooks")
  .header("Content-Type", "application/json")
  .body("[\n  \"21742633143463906290569050155826241533067272736897614950488156847949938836455\",\n  \"KXBTC-25-T100000\"\n]")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://synthesis.trade/api/v1/markets/orderbooks")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "[\n  \"21742633143463906290569050155826241533067272736897614950488156847949938836455\",\n  \"KXBTC-25-T100000\"\n]"

response = http.request(request)
puts response.read_body

{
  "success": true,
  "response": [
    {
      "venue": "polymarket",
      "orderbook": {
        "condition_id": "0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910",
        "token_id": "21742633143463906290569050155826241533067272736897614950488156847949938836455",
        "bids": {
          "0.61": "1000",
          "0.60": "800"
        },
        "asks": {
          "0.62": "900",
          "0.63": "600"
        },
        "best_bid": "0.61",
        "best_ask": "0.62",
        "hash": "abc123",
        "created_at": "2026-01-01T00:00:00"
      }
    },
    {
      "venue": "kalshi",
      "orderbook": {
        "market_id": "KXBTC-25-T100000",
        "yes": {
          "bids": {
            "58": "25"
          },
          "asks": {
            "60": "15"
          },
          "best_bid": "58",
          "best_ask": "60"
        },
        "no": {
          "bids": {
            "40": "15"
          },
          "asks": {
            "42": "20"
          },
          "best_bid": "40",
          "best_ask": "42"
        },
        "sequence": 12345,
        "created_at": "2026-01-01T00:00:00"
      }
    }
  ]
}

{
  "success": false,
  "response": "Invalid markets"
}