Capital.com API PUT /api/v1/session

PUT/api/v1/sessionversion v1Session

Switch the session to another of your financial accounts. Later calls then act on that account.

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 unofficialopen-api.capital.comchecked 12 Oct 2026

Read on Capital.com's own reference at open-api.capital.com on 12 Oct 2026: method, path, parameters and the example response. The reference does not flag the two session headers as required on each call. Its introduction says they should be passed on every request after login, which is why they are recorded as required.

Parameters

Name	In	Type	Description
Content-Typerequired	header	string	Send application/json on a request with a body.
accountIdrequired	body	string	Identifier of the account to switch to, from GET /api/v1/accounts.

Authentication headers

Name	Type	Description
CSTrequired	string	Access token returned in the CST response header of POST /session. Valid for 10 minutes after last use. Placeholder only.
X-SECURITY-TOKENrequired	string	Account token returned in the X-SECURITY-TOKEN response header of POST /session. It selects the financial account. Placeholder only.

Request

Written from the method, path and parameters recorded on this page, against the demo host. 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 samples send it as JSON with a Content-Type of application/json (in Python, passing json= sets that header) and a placeholder for each of the 1 body field the record marks as required. Each placeholder has to be replaced with a real value before the request can succeed.

Python

# Set CAPITAL_CST, CAPITAL_SECURITY_TOKEN as environment variables first. Never paste real values into code.
# CAPITAL_CST and CAPITAL_SECURITY_TOKEN hold the CST and X-SECURITY-TOKEN headers that POST /api/v1/session returns: step 3 of the quickstart (/brokers/capital-com/quickstart#step-3) captures them and this sample reads them back.
# Replace each {placeholder}, "..." and 0 with a real value before running.
import os
import requests

BASE_URL = "https://demo-api-capital.backend-capital.com"  # the demo host
headers = {
    "CST": os.environ["CAPITAL_CST"],
    "X-SECURITY-TOKEN": os.environ["CAPITAL_SECURITY_TOKEN"],
    "Content-Type": "application/json",
}
body = {"accountId": "..."}
resp = requests.put(BASE_URL + "/api/v1/session", headers=headers, json=body, timeout=10)
resp.raise_for_status()
print(resp.json())

JavaScript

// Set CAPITAL_CST, CAPITAL_SECURITY_TOKEN as environment variables first. Never paste real values into code.
// CAPITAL_CST and CAPITAL_SECURITY_TOKEN hold the CST and X-SECURITY-TOKEN headers that POST /api/v1/session returns: step 3 of the quickstart (/brokers/capital-com/quickstart#step-3) captures them and this sample reads them back.
// Replace each {placeholder}, "..." and 0 with a real value before running.
// Run as a module, for example a .mjs file, on a Node version that has fetch built in.
const BASE_URL = "https://demo-api-capital.backend-capital.com"; // the demo host
const res = await fetch(BASE_URL + "/api/v1/session", {
  method: "PUT",
  headers: {
    "CST": process.env.CAPITAL_CST,
    "X-SECURITY-TOKEN": process.env.CAPITAL_SECURITY_TOKEN,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({"accountId": "..."}),
});
if (!res.ok) throw new Error(`HTTP ${res.status}`);
console.log(await res.json());

curl

# Set CAPITAL_CST, CAPITAL_SECURITY_TOKEN as environment variables first. Never paste real values into code.
# CAPITAL_CST and CAPITAL_SECURITY_TOKEN hold the CST and X-SECURITY-TOKEN headers that POST /api/v1/session returns: step 3 of the quickstart (/brokers/capital-com/quickstart#step-3) captures them and this sample reads them back.
# Replace each {placeholder}, "..." and 0 with a real value before running.
curl -X PUT "https://demo-api-capital.backend-capital.com/api/v1/session" \
  -H "CST: $CAPITAL_CST" \
  -H "X-SECURITY-TOKEN: $CAPITAL_SECURITY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"accountId": "..."}'

Response

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

{
  "_mock": true,
  "trailingStopsEnabled": false,
  "dealingEnabled": true,
  "hasActiveDemoAccounts": true,
  "hasActiveLiveAccounts": false
}

Limits that apply at Capital.com

Limit	Value	Scope	Source
Headline limit	10/s per user	user	open-api.capital.comchecked 18 Sep 2026

Capital.com API errors you may meet

All Capital.com API error codes, including 18 more not listed here.