> ## Documentation Index
> Fetch the complete documentation index at: https://developers.kit.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Bulk add subscribers to forms
> Adding subscribers to double opt-in forms will trigger sending an Incentive Email. Subscribers already added to the specified form will not receive the Incentive Email again. For more information about double opt-in see "[Double opt-in](#double-opt-in)".
The subscribers being added to the form must already exist. Subscribers can be created in bulk using the "[Bulk create subscriber](#bulk-create-subscribers)" endpoint.
See "[Bulk & async processing](#bulk-amp-async-processing)" for more information.
## OpenAPI
````yaml /api-reference/v4.json post /v4/bulk/forms/subscribers
openapi: 3.0.3
info:
title: Kit API
version: '4.0'
servers:
- url: https://api.kit.com
security: []
paths:
/v4/bulk/forms/subscribers:
post:
tags:
- Forms
summary: Bulk add subscribers to forms
description: >-
Adding subscribers to double opt-in forms will trigger sending an
Incentive Email. Subscribers already added to the specified form will
not receive the Incentive Email again. For more information about double
opt-in see "[Double opt-in](#double-opt-in)".
The subscribers
being added to the form must already exist. Subscribers can be created
in bulk using the "[Bulk create subscriber](#bulk-create-subscribers)"
endpoint.
See "[Bulk & async
processing](#bulk-amp-async-processing)" for more information.
parameters: []
requestBody:
content:
application/json:
schema:
type: object
properties:
additions:
type: array
items:
type: object
properties:
form_id:
type: integer
nullable: true
subscriber_id:
type: integer
nullable: true
referrer:
type: string
required:
- form_id
- subscriber_id
callback_url:
type: string
nullable: true
required:
- additions
example:
additions:
- form_id: 0
subscriber_id: 0
- form_id: 1
subscriber_id: 1
- form_id: 2
subscriber_id: 2
- form_id: 3
subscriber_id: 3
callback_url: null
responses:
'200':
description: >-
Adds subscribers to forms synchronously when 100 or less
form/subscribers are requested
content:
application/json:
schema:
type: object
properties:
subscribers:
type: array
items:
type: object
properties:
id:
type: integer
first_name:
type: string
email_address:
type: string
created_at:
type: string
added_at:
type: string
referrer:
type: string
referrer_utm_parameters:
type: object
properties:
source:
type: string
medium:
type: string
campaign:
type: string
term:
type: string
content:
type: string
required:
- source
- medium
- campaign
- term
- content
required:
- id
- first_name
- email_address
- created_at
- added_at
- referrer
- referrer_utm_parameters
failures:
type: array
items:
type: object
properties:
errors:
type: array
items:
type: string
subscription:
type: object
properties:
form_id:
type: integer
nullable: true
subscriber_id:
type: integer
nullable: true
referrer:
type: string
required:
- form_id
- subscriber_id
- referrer
required:
- errors
- subscription
required:
- subscribers
- failures
example:
subscribers:
- id: 612
first_name: Sub
email_address: sub@example.com
created_at: '2023-02-17T11:43:55Z'
added_at: '2023-02-17T11:43:55Z'
referrer: >-
https://mywebsite.com/bfpromo/?utm_source=facebook&utm_medium=cpc&utm_campaign=black_friday&utm_term=car_owners&utm_content=get_10_off
referrer_utm_parameters:
source: facebook
medium: cpc
campaign: black_friday
term: car_owners
content: get_10_off
- id: 612
first_name: Sub
email_address: sub@example.com
created_at: '2023-02-17T11:43:55Z'
added_at: '2023-02-17T11:43:55Z'
referrer: >-
https://mywebsite.com/bfpromo/?utm_source=facebook&utm_medium=cpc&utm_campaign=black_friday&utm_term=car_owners&utm_content=get_10_off
referrer_utm_parameters:
source: facebook
medium: cpc
campaign: black_friday
term: car_owners
content: get_10_off
failures:
- errors:
- Subscriber does not exist
subscription:
form_id: 124
subscriber_id: null
referrer: >-
https://mywebsite.com/bfpromo/?utm_source=facebook&utm_medium=cpc&utm_campaign=black_friday&utm_term=car_owners&utm_content=get_10_off
- errors:
- Form does not exist
subscription:
form_id: null
subscriber_id: 612
referrer: >-
https://mywebsite.com/bfpromo/?utm_source=facebook&utm_medium=cpc&utm_campaign=black_friday&utm_term=car_owners&utm_content=get_10_off
'202':
description: >-
Adds subscribers to forms asynchronously when more than 100
form/subscribers are requested
content:
application/json:
schema:
type: object
properties: {}
example: {}
'401':
description: Returns a 401 if the token and/or account cannot be authenticated
content:
application/json:
schema:
type: object
properties:
errors:
type: array
items:
type: string
required:
- errors
example:
errors:
- The access token is invalid
'413':
description: >-
Returns a 413 when the size of the request would exceed the
account's data limit for enqueued bulk requests
content:
application/json:
schema:
type: object
properties:
errors:
type: array
items:
type: string
required:
- errors
example:
errors:
- >-
This request exceeds your queued bulk requests limit. Please
wait while we process your existing requests and try again
later.
'422':
description: Returns a 422 when `additions` is empty or not an array
content:
application/json:
schema:
type: object
properties:
errors:
type: array
items:
type: string
required:
- errors
example:
errors:
- No additions included for processing
security:
- OAuth2: []
components:
securitySchemes:
OAuth2:
description: Authenticate API requests via an OAuth token
type: oauth2
flows:
authorizationCode:
authorizationUrl: https://api.kit.com/v4/oauth/authorize
tokenUrl: https://api.kit.com/v4/oauth/token
refreshUrl: https://api.kit.com/v4/oauth/token
scopes:
read: Read access to Kit API v4
write: Write access to Kit API v4
````