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POST
/
v1
/
pm
/
events
/
{eventId}
/
markets
/
{marketId}
/
orders
Place order
curl --request POST \
  --url https://relay.bayse.markets/v1/pm/events/{eventId}/markets/{marketId}/orders \
  --header 'Content-Type: application/json' \
  --data '
{
  "side": "<string>",
  "outcomeId": "<string>",
  "amount": 123,
  "type": "<string>",
  "currency": "<string>",
  "price": 123,
  "timeInForce": "<string>",
  "postOnly": true,
  "stpMode": "<string>",
  "maxSlippage": 123,
  "expiresAt": "<string>"
}
'
import requests

url = "https://relay.bayse.markets/v1/pm/events/{eventId}/markets/{marketId}/orders"

payload = {
    "side": "<string>",
    "outcomeId": "<string>",
    "amount": 123,
    "type": "<string>",
    "currency": "<string>",
    "price": 123,
    "timeInForce": "<string>",
    "postOnly": True,
    "stpMode": "<string>",
    "maxSlippage": 123,
    "expiresAt": "<string>"
}
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({
    side: '<string>',
    outcomeId: '<string>',
    amount: 123,
    type: '<string>',
    currency: '<string>',
    price: 123,
    timeInForce: '<string>',
    postOnly: true,
    stpMode: '<string>',
    maxSlippage: 123,
    expiresAt: '<string>'
  })
};

fetch('https://relay.bayse.markets/v1/pm/events/{eventId}/markets/{marketId}/orders', 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://relay.bayse.markets/v1/pm/events/{eventId}/markets/{marketId}/orders",
  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([
    'side' => '<string>',
    'outcomeId' => '<string>',
    'amount' => 123,
    'type' => '<string>',
    'currency' => '<string>',
    'price' => 123,
    'timeInForce' => '<string>',
    'postOnly' => true,
    'stpMode' => '<string>',
    'maxSlippage' => 123,
    'expiresAt' => '<string>'
  ]),
  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://relay.bayse.markets/v1/pm/events/{eventId}/markets/{marketId}/orders"

	payload := strings.NewReader("{\n  \"side\": \"<string>\",\n  \"outcomeId\": \"<string>\",\n  \"amount\": 123,\n  \"type\": \"<string>\",\n  \"currency\": \"<string>\",\n  \"price\": 123,\n  \"timeInForce\": \"<string>\",\n  \"postOnly\": true,\n  \"stpMode\": \"<string>\",\n  \"maxSlippage\": 123,\n  \"expiresAt\": \"<string>\"\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://relay.bayse.markets/v1/pm/events/{eventId}/markets/{marketId}/orders")
  .header("Content-Type", "application/json")
  .body("{\n  \"side\": \"<string>\",\n  \"outcomeId\": \"<string>\",\n  \"amount\": 123,\n  \"type\": \"<string>\",\n  \"currency\": \"<string>\",\n  \"price\": 123,\n  \"timeInForce\": \"<string>\",\n  \"postOnly\": true,\n  \"stpMode\": \"<string>\",\n  \"maxSlippage\": 123,\n  \"expiresAt\": \"<string>\"\n}")
  .asString();
require 'uri'
require 'net/http'

url = URI("https://relay.bayse.markets/v1/pm/events/{eventId}/markets/{marketId}/orders")

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  \"side\": \"<string>\",\n  \"outcomeId\": \"<string>\",\n  \"amount\": 123,\n  \"type\": \"<string>\",\n  \"currency\": \"<string>\",\n  \"price\": 123,\n  \"timeInForce\": \"<string>\",\n  \"postOnly\": true,\n  \"stpMode\": \"<string>\",\n  \"maxSlippage\": 123,\n  \"expiresAt\": \"<string>\"\n}"

response = http.request(request)
puts response.read_body
{
  "engine": "AMM",
  "order": {
    "id": "e5f6a7b8-c9d0-1234-efab-567890123456",
    "outcome": "YES",
    "side": "BUY",
    "type": "MARKET",
    "status": "filled",
    "amount": 100,
    "price": 0.7235,
    "quantity": 138.21,
    "currency": "USD",
    "createdAt": "2026-02-17T12:00:00Z",
    "updatedAt": "2026-02-17T12:00:00Z"
  }
}

{
  "engine": "CLOB",
  "order": {
    "id": "f6a7b8c9-d0e1-2345-fabc-678901234567",
    "marketId": "b2c3d4e5-f6a7-8901-bcde-f12345678901",
    "userId": "9a8b7c6d-5e4f-3210-abcd-ef1234567890",
    "outcome": "YES",
    "side": "BUY",
    "orderType": "LIMIT",
    "stpMode": "SKIP",
    "type": "GTC",
    "status": "open",
    "amount": 100,
    "price": 0.70,
    "size": 100,
    "filledSize": 0,
    "remainingSize": 100,
    "avgFillPrice": 0,
    "fee": 0,
    "postOnly": false,
    "quantity": 0,
    "createdAt": "2026-02-17T12:00:00Z",
    "updatedAt": "2026-02-17T12:00:00Z"
  }
}

​
Authentication

Write authentication required — X-Public-Key, X-Timestamp, and X-Signature headers. See the Authentication guide.

​
Path parameters

​
eventId
string
required
UUID of the event.
​
marketId
string
required
UUID of the market.

​
Request body

​
side
string
required
BUY or SELL.
​
outcomeId
string
required
UUID of the outcome. Use the Get Event endpoint to find outcome IDs.
​
amount
number
required
Amount to spend (buy) or receive (sell), in the specified currency. Minimum: $1.00 USD / ₦100.00 NGN.
​
type
string
required
LIMIT or MARKET.
​
currency
string
USD (default) or NGN.
​
price
number
Limit price per share (0.01–0.99). Required for LIMIT orders.
​
timeInForce
string
GTC (good-til-cancelled, default for limit), GTD (good-til-date), FAK (fill-and-kill, default for market), or FOK (fill-or-kill).
​
postOnly
boolean
If true, the order is rejected instead of crossing the spread. Limit orders only. Default: false.
​
stpMode
string
Self-trade prevention mode. Controls how the engine resolves a match against another resting order from the same user. CLOB only. Default: SKIP. Unknown values fall back to SKIP.
  • SKIP — the match is silently skipped and both orders remain on the book.
  • CANCEL_OLDEST — the resting same-user maker is cancelled and refunded; the taker continues matching against other counterparties.
  • CANCEL_NEWEST — the incoming taker stops at the same-user match. If it had already filled against other users, those fills stand and the taker comes back as cancelled; otherwise it is rejected.
  • CANCEL_BOTH — the resting maker is cancelled and the taker is cancelled or rejected under the same rule as CANCEL_NEWEST.
​
maxSlippage
number
Maximum acceptable slippage for market orders (0.00–1.00).
​
expiresAt
string
ISO 8601 expiration timestamp. Required for GTD orders.

​
Example request

PUBLIC_KEY="pk_live_abcdef123456"
SECRET_KEY="sk_live_secret789xyz"
TIMESTAMP=$(date +%s)
METHOD="POST"
URL_PATH="/v1/pm/events/a1b2c3d4-e5f6-7890-abcd-ef1234567890/markets/b2c3d4e5-f6a7-8901-bcde-f12345678901/orders"
BODY='{"side":"BUY","outcomeId":"c3d4e5f6-a7b8-9012-cdef-345678901234","amount":100,"type":"MARKET","currency":"USD"}'

BODY_HASH=$(printf '%s' "$BODY" | openssl dgst -sha256 -hex 2>/dev/null | sed 's/.*= //')
PAYLOAD="${TIMESTAMP}.${METHOD}.${URL_PATH}.${BODY_HASH}"
SIGNATURE=$(printf '%s' "$PAYLOAD" | openssl dgst -sha256 -hmac "$SECRET_KEY" -binary | base64)

curl -X POST "https://relay.bayse.markets${URL_PATH}" \
  -H "X-Public-Key: ${PUBLIC_KEY}" \
  -H "X-Timestamp: ${TIMESTAMP}" \
  -H "X-Signature: ${SIGNATURE}" \
  -H "Content-Type: application/json" \
  -d "$BODY"

PUBLIC_KEY="pk_live_abcdef123456"
SECRET_KEY="sk_live_secret789xyz"
TIMESTAMP=$(date +%s)
METHOD="POST"
URL_PATH="/v1/pm/events/a1b2c3d4-e5f6-7890-abcd-ef1234567890/markets/b2c3d4e5-f6a7-8901-bcde-f12345678901/orders"
BODY='{"side":"BUY","outcomeId":"c3d4e5f6-a7b8-9012-cdef-345678901234","amount":100,"type":"LIMIT","price":0.70,"currency":"USD"}'

BODY_HASH=$(printf '%s' "$BODY" | openssl dgst -sha256 -hex 2>/dev/null | sed 's/.*= //')
PAYLOAD="${TIMESTAMP}.${METHOD}.${URL_PATH}.${BODY_HASH}"
SIGNATURE=$(printf '%s' "$PAYLOAD" | openssl dgst -sha256 -hmac "$SECRET_KEY" -binary | base64)

curl -X POST "https://relay.bayse.markets${URL_PATH}" \
  -H "X-Public-Key: ${PUBLIC_KEY}" \
  -H "X-Timestamp: ${TIMESTAMP}" \
  -H "X-Signature: ${SIGNATURE}" \
  -H "Content-Type: application/json" \
  -d "$BODY"

import crypto from 'crypto';

const publicKey = 'pk_live_abcdef123456';
const secretKey = 'sk_live_secret789xyz';
const timestamp = Math.floor(Date.now() / 1000);
const method = 'POST';
const path = '/v1/pm/events/a1b2c3d4-e5f6-7890-abcd-ef1234567890/markets/b2c3d4e5-f6a7-8901-bcde-f12345678901/orders';
const body = JSON.stringify({
  side: 'BUY',
  outcomeId: 'c3d4e5f6-a7b8-9012-cdef-345678901234',
  amount: 100,
  type: 'LIMIT',
  price: 0.70,
  currency: 'USD',
});

const bodyHash = crypto.createHash('sha256').update(body).digest('hex');
const payload = `${timestamp}.${method}.${path}.${bodyHash}`;
const signature = crypto
  .createHmac('sha256', secretKey)
  .update(payload)
  .digest('base64');

const response = await fetch(`https://relay.bayse.markets${path}`, {
  method,
  headers: {
    'X-Public-Key': publicKey,
    'X-Timestamp': timestamp.toString(),
    'X-Signature': signature,
    'Content-Type': 'application/json',
  },
  body,
});
const order = await response.json();

import hmac, hashlib, base64, json, time, requests

public_key = 'pk_live_abcdef123456'
secret_key = 'sk_live_secret789xyz'
timestamp = int(time.time())
method = 'POST'
path = '/v1/pm/events/a1b2c3d4-e5f6-7890-abcd-ef1234567890/markets/b2c3d4e5-f6a7-8901-bcde-f12345678901/orders'
body = json.dumps({
    'side': 'BUY',
    'outcomeId': 'c3d4e5f6-a7b8-9012-cdef-345678901234',
    'amount': 100,
    'type': 'LIMIT',
    'price': 0.70,
    'currency': 'USD',
})

body_hash = hashlib.sha256(body.encode()).hexdigest()
payload = f'{timestamp}.{method}.{path}.{body_hash}'
signature = base64.b64encode(
    hmac.new(secret_key.encode(), payload.encode(), hashlib.sha256).digest()
).decode()

resp = requests.post(
    f'https://relay.bayse.markets{path}',
    headers={
        'X-Public-Key': public_key,
        'X-Timestamp': str(timestamp),
        'X-Signature': signature,
        'Content-Type': 'application/json',
    },
    data=body,
)
order = resp.json()

import (
    "crypto/hmac"
    "crypto/sha256"
    "encoding/base64"
    "encoding/hex"
    "fmt"
    "strconv"
    "strings"
    "time"
)

timestamp := time.Now().Unix()
method := "POST"
urlPath := "/v1/pm/events/a1b2c3d4-e5f6-7890-abcd-ef1234567890/markets/b2c3d4e5-f6a7-8901-bcde-f12345678901/orders"
body := []byte(`{"side":"BUY","outcomeId":"c3d4e5f6-a7b8-9012-cdef-345678901234","amount":100,"type":"LIMIT","price":0.70,"currency":"USD"}`)

bodySum := sha256.Sum256(body)
bodyHash := hex.EncodeToString(bodySum[:])
payload := fmt.Sprintf("%d.%s.%s.%s", timestamp, method, urlPath, bodyHash)
mac := hmac.New(sha256.New, []byte("sk_live_secret789xyz"))
mac.Write([]byte(payload))
signature := base64.StdEncoding.EncodeToString(mac.Sum(nil))

req, _ := http.NewRequest("POST", "https://relay.bayse.markets"+urlPath, strings.NewReader(string(body)))
req.Header.Set("X-Public-Key", "pk_live_abcdef123456")
req.Header.Set("X-Timestamp", strconv.FormatInt(timestamp, 10))
req.Header.Set("X-Signature", signature)
req.Header.Set("Content-Type", "application/json")
resp, _ := http.DefaultClient.Do(req)

​
Response

The response contains an engine field indicating the market type, and an order object with the order details.
​
engine
string
AMM or CLOB.
​
order
object
The placed order. Fields vary by engine type.
{
  "engine": "AMM",
  "order": {
    "id": "e5f6a7b8-c9d0-1234-efab-567890123456",
    "outcome": "YES",
    "side": "BUY",
    "type": "MARKET",
    "status": "filled",
    "amount": 100,
    "price": 0.7235,
    "quantity": 138.21,
    "currency": "USD",
    "createdAt": "2026-02-17T12:00:00Z",
    "updatedAt": "2026-02-17T12:00:00Z"
  }
}

{
  "engine": "CLOB",
  "order": {
    "id": "f6a7b8c9-d0e1-2345-fabc-678901234567",
    "marketId": "b2c3d4e5-f6a7-8901-bcde-f12345678901",
    "userId": "9a8b7c6d-5e4f-3210-abcd-ef1234567890",
    "outcome": "YES",
    "side": "BUY",
    "orderType": "LIMIT",
    "stpMode": "SKIP",
    "type": "GTC",
    "status": "open",
    "amount": 100,
    "price": 0.70,
    "size": 100,
    "filledSize": 0,
    "remainingSize": 100,
    "avgFillPrice": 0,
    "fee": 0,
    "postOnly": false,
    "quantity": 0,
    "createdAt": "2026-02-17T12:00:00Z",
    "updatedAt": "2026-02-17T12:00:00Z"
  }
}

​
Replacing market-maker quotes with stpMode

A market maker re-quoting on both sides of a CLOB book risks crossing its own resting orders mid-update. Setting stpMode to CANCEL_OLDEST cancels the stale same-user maker server-side as the new quote arrives, so the new order can continue matching against external counterparties without sitting next to a duplicate of itself.
cURL
BODY='{"side":"BUY","outcomeId":"c3d4e5f6-a7b8-9012-cdef-345678901234","amount":100,"type":"LIMIT","price":0.71,"timeInForce":"GTC","stpMode":"CANCEL_OLDEST","currency":"USD"}'

curl -X POST "https://relay.bayse.markets/v1/pm/events/${EVENT_ID}/markets/${MARKET_ID}/orders" \
  -H "X-Public-Key: ${PUBLIC_KEY}" \
  -H "X-Timestamp: ${TIMESTAMP}" \
  -H "X-Signature: ${SIGNATURE}" \
  -H "Content-Type: application/json" \
  -d "$BODY"