> ## 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.
# Update a subscriber
> We will ignore custom fields that don't already exist in your account. We will not return an error if you try to add data to a custom field that does not exist. Please use Create a custom field to create custom fields before setting for subscribers.
NOTE: We support creating/updating a maximum of 140 custom fields at a time.
## OpenAPI
````yaml /api-reference/v4.json put /v4/subscribers/{id}
openapi: 3.0.3
info:
title: Kit API
version: '4.0'
servers:
- url: https://api.kit.com
security: []
paths:
/v4/subscribers/{id}:
put:
tags:
- Subscribers
summary: Update a subscriber
description: >-
We will ignore custom fields that don't already exist in your account.
We will not return an error if you try to add data to a custom field
that does not exist. Please use Create
a custom field to create custom fields before setting for
subscribers.
NOTE: We support
creating/updating a maximum of 140 custom fields at a time.
parameters:
- name: id
in: path
required: true
schema:
type: integer
example: 379
requestBody:
content:
application/json:
schema:
type: object
properties:
first_name:
type: string
nullable: true
email_address:
type: string
fields:
type: object
nullable: true
properties:
Last name:
type: string
Birthday:
type: string
Source:
type: string
Role:
type: string
Company:
type: string
Postal code:
type: string
Website:
type: string
Social media:
type: string
How did you hear about us?:
type: string
Interests:
type: string
Coupon:
type: string
required:
- Last name
- Birthday
- Source
required:
- email_address
example:
first_name: Alice
email_address: alice@convertkit.dev
fields:
Last name: Lamarr
Birthday: Feb 17
Source: landing page
Role: Software developer
Company: Convertkit
Postal code: '83702'
Website: convertkit.com
Social media: https://www.linkedin.com/company/convertkit
How did you hear about us?: Social media
Interests: Monetization
Coupon: ''
responses:
'200':
description: Updates the subscriber's email address and first name
content:
application/json:
schema:
type: object
properties:
subscriber:
type: object
properties:
id:
type: integer
first_name:
type: string
nullable: true
email_address:
type: string
state:
type: string
enum:
- active
- cancelled
- bounced
- complained
- inactive
created_at:
type: string
fields:
type: object
properties: {}
required:
- id
- first_name
- email_address
- state
- created_at
- fields
required:
- subscriber
example:
subscriber:
id: 374
first_name: Alice
email_address: alice@convertkit.dev
state: active
created_at: '2023-02-17T11:43:55Z'
fields: {}
'202':
description: >-
Returns a 202 and asynchronously updates custom fields for the
subscriber when more than 10 custom fields are included in the
request
content:
application/json:
schema:
type: object
properties:
subscriber:
type: object
properties:
id:
type: integer
first_name:
type: string
nullable: true
email_address:
type: string
state:
type: string
enum:
- active
- cancelled
- bounced
- complained
- inactive
created_at:
type: string
fields:
type: object
properties: {}
required:
- id
- first_name
- email_address
- state
- created_at
- fields
required:
- subscriber
example:
subscriber:
id: 376
first_name: Alice
email_address: alice@convertkit.dev
state: active
created_at: '2023-02-17T11:43:55Z'
fields: {}
'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
'404':
description: Returns a 404 when the provided id does not exist
content:
application/json:
schema:
type: object
properties:
errors:
type: array
items:
type: string
required:
- errors
example:
errors:
- Not Found
'422':
description: Returns 422 with an error when email address is already in use
content:
application/json:
schema:
type: object
properties:
errors:
type: array
items:
type: string
required:
- errors
example:
errors:
- Email address has already been taken
security:
- API Key: []
- OAuth2: []
components:
securitySchemes:
API Key:
description: Authenticate API requests via an API Key
type: apiKey
in: header
name: X-Kit-Api-Key
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
````