> ## Documentation Index
> Fetch the complete documentation index at: https://developer.lemlist.com/llms.txt
> Use this file to discover all available pages before exploring further.
> Creates a new company or updates an existing one based on domain or LinkedIn URL.
# Add and update company
export const SnippetObjectReference = ({objectName, objectPath = null}) => {
const lowerCaseObjectName = objectName.toLowerCase();
if (lowerCaseObjectName === 'lead' || lowerCaseObjectName === 'leads') {
return
This endpoint uses the {objectName} object. Make sure to also check the {lowerCaseObjectName === 'lead' ? 'Contact' : 'Lead'} object to understand the distinction between the two.
;
}
return
This endpoint uses the {objectName} object.
;
};
Creates a new company in your CRM, or updates an existing one if a company with the same `domain`, `linkedinUrl`, or `linkedinUrlSalesNav` already exists (upsert).
During updates, only non-empty fields are applied — null or empty values are ignored to preserve existing data.
## Upsert matching
The endpoint matches existing companies by:
| Identifier | Description |
| --------------------- | --------------------------------------------------------------------------------------------- |
| `companyId` | Existing company ID — updates a specific company directly, bypassing domain/LinkedIn matching |
| `domain` | Company website domain (e.g. `lemlist.com`) — primary unique key |
| `linkedinUrl` | LinkedIn company page URL — alternative unique key |
| `linkedinUrlSalesNav` | LinkedIn Sales Navigator company URL — alternative unique key |
If a company with the same `domain`, `linkedinUrl`, or `linkedinUrlSalesNav` already exists, the endpoint updates it instead of creating a duplicate.
When `companyId` is provided, the company is matched by its ID directly — `name` and `domain` are not required and are not used for matching (they are stored as data if provided). Without `companyId`, both `name` and `domain` remain required.
`companyId` can only be used to **update** an existing company. It cannot be used to create a new company — use `name` and `domain` for creation.
## Owner assignment
You can assign an owner to the company using the `companyOwner` field. Accepted formats:
| Format | Example |
| ----------------- | ----------------------- |
| User ID | `usr_2aB3cD4eF5gH6iJ7k` |
| Team member email | `john@yourcompany.com` |
If the provided value does not match a team member (invalid format, unknown email, or unknown user ID), the owner is **silently ignored** — no error or warning is returned. On creation, the company defaults to the API key owner.
## OpenAPI
````yaml post /companies
openapi: 3.0.0
info:
title: lemlist API
version: 1.0.0
description: >-
Welcome to the lemlist Developer Documentation.
lemlist is very customizable and open. You'll find on this page all the API
and integration you can do with lemlist.
# Rate Limit
lemlist's API rate limits requests in order to prevent abuse and overload of
our services.
Rate limits are applied on all routes and per API key performing the
request.
The rate limits are **20** requests per **2** seconds.
The response provides any information you may need about it:
| Header | Description |
| --- | --- |
| Retry-After | The number of seconds in which you can retry |
| X-RateLimit-Limit | The maximum requests in that time |
| X-RateLimit-Remaining | The number of remaining requests you can make |
| X-RateLimit-Reset | The date when the rate limit will reset |
_Example of values for the rate limit headers_
``` json
{
"Retry-After": 2,
"X-RateLimit-Limit": 20,
"X-RateLimit-Remaining": 7,
"X-RateLimit-Reset" : "Tue Feb 16 2021 09:02:42 GMT+0100 (Central European Standard Time)"
}
```
# Definitions
## Team
A team is the entity of lemlist that can handle users and billing.
## Credits
Credits are the coins a team uses to enrich emails, LinkedIn URLs, etc. via
the enrich route. Each enrichment feature needs a certain amount of credits
to run.
## User
You use a user account to connect to lemlist and send messages via the
connected emails or LinkedIn account.
## Campaign
A campaign is the entity to automate outreach. A campaign has multiple
sequences composed of steps.
## Lead
A lead is a person that you try to contact via a campaign.
## Activity
An activity is the history of all the steps.
## Unsubscribe
An unsubscribe occurs when a person decides they don't want to receive
emails from you anymore.
# Authentication
All API routes use the dedicated subdomain `api.lemlist.com`.
lemlist uses API keys to allow access to the API. You can get your lemlist
API key at our [integration
page](https://app.lemlist.com/settings/integrations).
You need to add the `Authorization` header using the `Basic` authentication
type. `login:password` **where the login is always empty and the password is
the API key**.
⚠️ **Don't forget to add the semicolon (**`:`**) before your API key in curl
command.**
> To authorize, use this code:
``` shell
curl https://api.lemlist.com/api/team \
--user ":YourApiKey"
```
**Make sure to replace** **`YourApiKey`** **with your API key.**
# Give feedback
If you want to report a bug, ask for data, or share with us a use case,
please fill this [form](https://lemlist.typeform.com/to/mfVlkyGf). It will
help us centralize your needs!
servers:
- url: https://api.lemlist.com/api
security:
- basicAuth: []
paths:
/companies:
post:
tags:
- Companies
summary: Add and update company
description: >-
Creates a new company or updates an existing one (upsert). If a company
with the same domain, LinkedIn URL, or Sales Navigator URL already
exists, it will be updated with the provided non-empty fields. Null or
empty values are ignored during updates to preserve existing data. You
can target an existing company directly by providing `companyId`,
bypassing domain/LinkedIn matching — in that case `name` and `domain`
become optional.
parameters: []
requestBody:
required: true
content:
application/json:
schema:
type: object
properties:
companyId:
type: string
description: >-
Existing company ID. Updates a specific company by ID,
bypassing domain/LinkedIn matching. Can only be used to
update an existing company, not to create a new one. When
provided, `name` and `domain` become optional.
name:
type: string
description: Company name. Required unless `companyId` is provided.
domain:
type: string
description: >-
Company website domain (e.g. `lemlist.com`). Used as a
unique key for upsert matching. Required unless `companyId`
is provided.
linkedinUrl:
type: string
description: >-
LinkedIn company page URL. Used as an alternative unique key
for upsert matching.
linkedinUrlSalesNav:
type: string
description: >-
LinkedIn Sales Navigator company URL. Used as an alternative
unique key for upsert matching.
companyOwner:
type: string
description: >-
Owner of the company. Can be a user ID (e.g. `usr_...`) or a
team member's email address. If the provided value does not
match a team member, the owner defaults to the API key
owner.
industry:
type: string
description: Industry sector of the company.
location:
type: string
description: Geographic location of the company.
size:
type: string
description: Company size.
specialties:
type: string
description: Company specialties.
tagline:
type: string
description: Company tagline.
type:
type: string
description: Company type.
description:
type: string
description: Company description.
foundedOn:
type: string
description: Company founding date.
headquarters:
type: string
description: Company headquarters location.
picture:
type: string
description: URL of the company logo or picture.
source:
type: string
description: >-
Origin of the company record. Set on creation only and
cannot be updated afterwards. Defaults to `api`.
default: api
additionalProperties:
description: >-
Any additional key is treated as a custom field. Custom fields
must be registered in the team's CRM field registry
beforehand.
example:
name: Acme Corp
domain: acme.com
linkedinUrl: https://linkedin.com/company/acme
industry: Technology
location: San Francisco, CA
responses:
'200':
description: Existing company updated (upsert matched by domain or LinkedIn URL)
content:
application/json:
schema:
type: object
properties:
success:
type: boolean
data:
type: object
description: >-
Same shape as the 201 response, with `created: false` and
`updated: true`.
example:
success: true
data:
_id: cpn_gG7PsmZFpEAnpMCHO
teamId: tea_8QvkOiBfPdb2ZRhHi
domain: acme.com
fields:
name: Acme Corp
industry: Technology
location: San Francisco, CA
ownerId: usr_ahfFktBBHUIxbVG5P
source: api
createdAt: '2025-10-28T00:40:37.917Z'
createdBy: usr_ahfFktBBHUIxbVG5P
created: false
updated: true
'201':
description: Company created successfully
content:
application/json:
schema:
type: object
properties:
success:
type: boolean
data:
type: object
properties:
_id:
type: string
description: Unique company identifier
teamId:
type: string
description: Team ID
domain:
type: string
description: Company domain
linkedinUrl:
type: string
description: LinkedIn URL
fields:
type: object
description: >-
Key/value fields (name, picture, industry, location,
custom fields, etc.)
additionalProperties: true
ownerId:
type: string
description: Owner user ID
source:
type: string
description: Record origin
createdAt:
type: string
format: date-time
description: Creation timestamp
createdBy:
type: string
description: User ID who created the record
created:
type: boolean
description: >-
`true` when a new company was created, `false` when an
existing company was updated.
updated:
type: boolean
description: >-
Present and set to `true` only when an existing
company was updated (i.e. `created` is `false`).
warnings:
type: array
description: Optional warnings (e.g. owner resolution issues).
items:
type: object
properties:
code:
type: string
message:
type: string
example:
success: true
data:
_id: cpn_gG7PsmZFpEAnpMCHO
teamId: tea_8QvkOiBfPdb2ZRhHi
domain: acme.com
linkedinUrl: https://www.linkedin.com/company/acme
fields:
name: Acme Corp
industry: Technology
location: San Francisco, CA
ownerId: usr_ahfFktBBHUIxbVG5P
source: api
createdAt: '2025-10-28T00:40:37.917Z'
createdBy: usr_ahfFktBBHUIxbVG5P
created: true
'400':
description: Validation error
content:
application/json:
schema:
type: object
properties:
success:
type: boolean
error:
type: object
properties:
code:
type: string
description: >-
Error code: `MISSING_REQUIRED_FIELD`,
`INVALID_COMPANY_ID`, `COMPANY_NOT_FOUND_BY_ID`,
`INVALID_DOMAIN`, `INVALID_LINKEDIN_URL`, or
`INVALID_FIELD`.
message:
type: string
example:
success: false
error:
code: MISSING_REQUIRED_FIELD
message: 'Missing required field: name'
'401':
description: The authentication you supplied is incorrect
content:
text/plain:
example: The authentication you supplied is incorrect
components:
securitySchemes:
basicAuth:
type: http
scheme: basic
````