---
title: "Create Knot Zero Link"
method: POST
path: "/zero-link/create"
---

# Create Knot Zero Link

`POST /zero-link/create`

## Request

- Base URL: `https://development.knotapi.com`
- URL: `https://development.knotapi.com/zero-link/create`
- Auth: HTTP basic

Create a Knot Zero link for a single user.

## Request body

- object
  - `type` 'card_switcher' | 'link', required: Product to associate the link with. Use `link` with `merchant_id` to open the link on a single merchant.
  - `merchant_id` integer: ID of the merchant to open the link on. **Required when `type = link`.** Get merchant IDs, which are the same in every environment, from [List Merchants](/api-reference/merchants/list-merchants).
  - `phone_number` string, required: User's phone number in E.164 format. Must be a valid US or Canadian phone number. Knot sends a one-time code to this number to verify the user each time they open the link.
  - `external_user_id` string, required: Your unique identifier for the user.
  - `card_id` string: Your unique identifier for the user's card. **Required when `type = card_switcher`.**

## Response `200`

Successful request.

- object
  - `link` string: The Knot Zero link for the user: your base link with a unique token appended that references the user's stored parameters. Share it as a URL or encode it as a QR code. The link can be opened any number of times, with a new one-time code each time, and expires after 1 year. It stops working earlier if you create a new link for the same user and card, or revoke it.
  - `token` string: The unique token in `link`, returned separately so you don't need to parse it from the link.

## Other responses

- `400`: Bad request.
- `401`: Unauthorized request.
- `403`: Forbidden request.
- `429`: Too many requests. Limited to 600 requests per minute per client.

## Changes

- **2026-11-03** `f10ecfa12c00`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/knotapi/apis/knot-api/changes/zero-link/create/post.md)

---

[API](https://skmtc.dev/knotapi/apis/knot-api.md) - [All operations](https://skmtc.dev/knotapi/apis/knot-api/llms.txt) - [OpenAPI document](https://skmtc.dev/knotapi/apis/knot-api/revisions/f10ecfa12c00?raw)