Interactive Brokers API POST /iserver/reply/{replyId}

POST/iserver/reply/{replyId}version v1Orders

Answers a warning that came back from an order submission and continues with the order. The answer can bring another question.

Risk warning: CFDs and spread bets are complex instruments and come with a high risk of losing money rapidly due to leverage. You can lose money on these products, and each provider publishes its own loss figure under FCA rules. You should consider whether you understand how they work and whether you can afford to take the high risk of losing your money. Automated and API trading can amplify losses through bugs, connectivity failures and runaway orders.

Independent and unofficialinteractivebrokers.comchecked 18 Sep 2026

The 200 body can also be another reply message, an error object, or orderReplyNotFound when the reply ID does not exist.

Parameters

Name	In	Type	Description
replyIdrequired	path	string	The UUID of the reply message, from the order submission response.
confirmed	body	boolean	true answers the question in the affirmative and proceeds with the order.

Authentication headers

Name	Type	Description
Authorization	string	OAuth only; the Gateway sends none. On the OAuth host this is the SSO bearer token IBKR's reference lists for this call. With the Client Portal Gateway on your own computer the browser login holds the session. Placeholder only.

Request

Written from the method, path and parameters recorded on this page. No demo host is recorded as a plain address for this API, so the samples read the base address from an environment variable. Not executed against a live or demo account. Credentials are read from environment variables on your own machine and are never entered on this site. The request builder writes these same snippets, from the same record.

This call takes a request body. The record marks no body field as required, so the samples send an empty JSON object with a Content-Type of application/json (in Python, passing json= sets that header). Add the fields the call needs from the parameters above before the request can succeed.

Python

# Set IBKR_BASE_URL as an environment variable first. Never paste real values into code.
# No demo host is recorded as a plain address for this API, so the base address is read from IBKR_BASE_URL.
# Replace each {placeholder}, "..." and 0 with a real value before running.
# Optional and not shown: headers Authorization; body fields confirmed.
import os
import requests

BASE_URL = os.environ["IBKR_BASE_URL"]
headers = {}
body = {}
resp = requests.post(BASE_URL + "/iserver/reply/{replyId}", headers=headers, json=body, timeout=10)
resp.raise_for_status()
print(resp.json())

JavaScript

// Set IBKR_BASE_URL as an environment variable first. Never paste real values into code.
// No demo host is recorded as a plain address for this API, so the base address is read from IBKR_BASE_URL.
// Replace each {placeholder}, "..." and 0 with a real value before running.
// Optional and not shown: headers Authorization; body fields confirmed.
// Run as a module, for example a .mjs file, on a Node version that has fetch built in.
const BASE_URL = process.env.IBKR_BASE_URL;
const res = await fetch(BASE_URL + "/iserver/reply/{replyId}", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
  },
  body: JSON.stringify({}),
});
if (!res.ok) throw new Error(`HTTP ${res.status}`);
console.log(await res.json());

curl

# Set IBKR_BASE_URL as an environment variable first. Never paste real values into code.
# No demo host is recorded as a plain address for this API, so the base address is read from IBKR_BASE_URL.
# Replace each {placeholder}, "..." and 0 with a real value before running.
# Optional and not shown: headers Authorization; body fields confirmed.
curl -X POST "$IBKR_BASE_URL/iserver/reply/{replyId}" \
  -H "Content-Type: application/json" \
  -d '{}'

Response

A mock response. The values are invented, so check field names against the official reference.

[
  {
    "_mock": true,
    "order_id": "MOCK-ORDER-0001",
    "order_status": "PreSubmitted",
    "encrypt_message": "1"
  }
]

Limits that apply at Interactive Brokers

Limit	Value	Scope	Source
Global requests a second (Web API)	10	Per authenticated username, that is per Web API session	ibkrcampus.comchecked 12 Oct 2026corroborated by interactivebrokers.com/docs/web-api/trading/usage-and-availability/pacing-limitations
Historical market data requests	Either 10 req/s or 50 req/minute, as the page words it	GET /iserver/marketdata/history only	interactivebrokers.comchecked 12 Oct 2026corroborated by ibkrcampus.com/campus/ibkr-api-page/webapi-doc/
Market data snapshot requests a second	10	GET /iserver/marketdata/snapshot only	interactivebrokers.comchecked 12 Oct 2026corroborated by ibkrcampus.com/campus/ibkr-api-page/webapi-doc/
Order and trade list requests	1 req/5 s	GET /iserver/orders and GET /iserver/trades, each counted on its own	interactivebrokers.comchecked 12 Oct 2026corroborated by ibkrcampus.com/campus/ibkr-api-page/webapi-doc/
Session validation requests a minute	1	GET /sso/validate only	interactivebrokers.comchecked 12 Oct 2026corroborated by ibkrcampus.com/campus/ibkr-api-page/webapi-doc/
Session keep alive requests a second	1	GET /tickle only	interactivebrokers.comchecked 12 Oct 2026corroborated by ibkrcampus.com/campus/ibkr-api-page/webapi-doc/

Interactive Brokers API errors you may meet

All Interactive Brokers API error codes, including 505 more not listed here.