# Capital.com API PUT /api/v1/session

Independent and unofficial. Not affiliated with or endorsed by any broker or platform named here. Educational only: nothing here is advice, and nothing here recommends a broker or a trade.

This is the markdown version of https://openbrokerapi.com/brokers/capital-com/endpoints/put-session, written from the same records as that page.

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.

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

- Request: `PUT /api/v1/session`
- Version: v1
- Group: Session
- Status: verified. Source: [open-api.capital.com](https://open-api.capital.com/), checked 2026-10-12.
- Official reference: https://open-api.capital.com/

Note: 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

- `Content-Type` (in header, type string, required): Send application/json on a request with a body.
- `accountId` (in body, type string, required): Identifier of the account to switch to, from GET /api/v1/accounts.

### Authentication headers

- `CST` (type string, required): Access token returned in the CST response header of POST /session. Valid for 10 minutes after last use. Placeholder only.
- `X-SECURITY-TOKEN` (type string, required): 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 at https://openbrokerapi.com/tools/request-builder writes these same snippets, from the same record.

This call takes a request body. The samples send it as JSON with 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

```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

```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

```bash
# 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](https://open-api.capital.com/).

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

## Limits that apply at Capital.com

- Headline limit: 10/s per user
  - Scope: user
  - Status: verified. Source: [open-api.capital.com](https://open-api.capital.com/), checked 2026-09-18.
  - Note: Orders and new positions: 1 per 0.1 s. POST /session: 1 a second per API key. Demo: 1000 an hour for POST /positions and /workingorders.

## More on the Capital.com API

- [All Capital.com API endpoints](https://openbrokerapi.com/brokers/capital-com/endpoints): 36 documented, grouped by what they do.
- [Capital.com API quickstart](https://openbrokerapi.com/brokers/capital-com/quickstart)
- [All Capital.com API error codes](https://openbrokerapi.com/errors/capital-com)
- [Capital.com API page](https://openbrokerapi.com/brokers/capital-com): The full record: access, authentication, limits and the source for each.
- [Capital.com API as an OpenAPI file](https://openbrokerapi.com/specs/capital-com.json): Generated from these endpoint records. Independent and unofficial.

## Licence and how to cite

The records behind this page are all rights reserved. This file is the page itself, at its own address, in another format. It is not part of the CC BY 4.0 downloads listed at https://openbrokerapi.com/data. Quote from it with a link to the page.

Cite as: Capital.com API PUT /api/v1/session. Broker API Hub, https://openbrokerapi.com/brokers/capital-com/endpoints/put-session, newest check 2026-10-12.

Where you rely on a single figure, cite the source and the checked date printed beside it as well. Where this page and a broker's own documentation differ, the documentation wins.