---
title: "Add a list member"
method: POST
path: "/client/lists/members/add"
tags: ["Account actions"]
---

# Add a list member

`POST /client/lists/members/add`

## Request

- Base URL: `https://api.twittrapi.com`
- URL: `https://api.twittrapi.com/client/lists/members/add`
- Auth: API key in header `X-API-KEY`

Add an account to a list you own.

Reference: https://www.twittrapi.com/docs/account-actions/client-lists-members-add

## Query parameters

- `format` 'raw' | 'simple'

## Request body

- object
  - `cookie` string, required: Cookie header of your own logged-in X session: auth_token=...; ct0=... (guest_id is used when present). How to copy it: /docs/x-session.
  - `proxy` string, required: Your proxy, format http://user:pass@host:port. The requests to X go out through it. Used only for this request.
  - `list_id` string, required: Numeric ID of the list, the number in the list URL (x.com/i/lists/<id>).
  - `user_id` string: Numeric ID of the account to add. Either user_id or username is required; user_id is used when both are set.
  - `username` string: Handle, with or without @, used when user_id is not set. The API looks up the ID first; still one billed call.

## Response `200`

Wrapper built by the API: {"status_code": <X status>, "response": "<X response body as a string>"}. The HTTP status is X's status when X answered 4xx or 5xx, otherwise 200. Parse response a second time to get X's JSON.

With format=simple: {data: {success: true}}. When X reports an error inside the wrapper (for example a tweet that is already liked), the usual wrapper is returned unchanged.

- RawPassthrough: X's own JSON (raw format, the default), passed through unchanged. The shape is X's and can change; see https://www.twittrapi.com/docs/response-format.

## Other responses

- `400`: The body is not valid JSON. username is set but no such user exists ("This user could not be found."). Refunded.
- `401`: Missing or unknown API key. Not charged.
- `402`: No balance left, or the trial expired. Not charged. Top up in the dashboard.
- `403`: Key deactivated, or the endpoint is not in your plan (trial keys and account actions). Not charged.
- `407`: The proxy is unreachable or timed out.
- `422`: A required field is missing (including proxy), an ID is not numeric, or the cookie has no ct0. Also: the account is suspended, X rejected the session, or the text was already posted. Neither user_id nor username is set, user_id is not numeric, or the username lookup failed.
- `429`: Rate limit for your key exceeded. Not charged. No Retry-After header: back off exponentially.
- `500`: Something failed on our side or between us and X. Refunded (400, 407, 408, 409 or a 5xx error are refunded). Retry with backoff.
- `default`: Any status X answers with (for example 401, 403, 404): passed through with X's body.

---

[API](https://skmtc.dev/twittrapi/apis/twittrapi-api.md) · [All operations](https://skmtc.dev/twittrapi/apis/twittrapi-api/llms.txt) · [OpenAPI document](https://skmtc.dev/twittrapi/apis/twittrapi-api/revisions/0618e38b54c2?raw)