Lemlist

Lemlist is an AI-powered cold email platform that helps businesses generate more customers through personalized outreach campaigns, providing advanced email automation, lead generation tools, and analytics to optimize email marketing performance and increase conversion rates.

Power end-to-end data operations for your Lemlist API with Nexla. Our bi-directional Lemlist connector is purpose-built for Lemlist, making it simple to ingest data, sync it across systems, and deliver it anywhere — all with no coding required. Nexla turns API-sourced data into ready-to-use, reusable data products and makes it easy to send data to Lemlist or any other destination. With comprehensive monitoring, lineage tracking, and access controls, Nexla keeps your Lemlist workflows fast, secure, and fully governed.

Features

Type: API

SourceDestination

• Seamless API Integration: Connect to any endpoint as source or destination without coding, with automatic data product creation
• Visual Composition & Chaining: Build complex integrations using visual templates, chain API calls, and compose workflows with data validation and filtering
• API Proxy: Expose curated slices of your data securely with a secure and customizable API proxy that validates and transforms data on the fly
• Request optimization with intelligent batching, retry, and caching to minimize API calls and costs

Prerequisites

Before creating a Lemlist credential, you need to obtain a personal API key from your Lemlist account. The API key is required to authenticate with the Lemlist API using Basic Authentication.

To obtain your API key, follow these steps:

1. Sign in to your Lemlist account using your credentials.

2. Navigate to Settings > Integrations in your Lemlist account, or access your account settings from the account menu.

3. In the Integrations or API settings section, locate the API Keys or API Settings section where you can view and manage your API keys.

4. If you don't have an existing API key, click Generate API Key or Create API Key to create a new API key. You may be asked to provide a name or description for the key to help identify it later (e.g., "Nexla Integration").

5. After generating the API key, copy it immediately. The API key is typically displayed only once for security reasons and may not be accessible again after you navigate away from the page.

6. Store the API key securely, as you will need it to configure your Nexla credential. The API key provides full access to your Lemlist account data, so treat it as sensitive information.

The API key is used as the password in Basic Authentication, with an empty username. The credentials are sent in the Authorization header using Basic Authentication for all API requests to the Lemlist API. The Lemlist API provides access to various resources including campaigns, activities, unsubscribes, hooks, and leads. For detailed information about API key setup, authentication, and available API endpoints, refer to the Lemlist API documentation and Lemlist API authentication documentation.

Authenticate

Credentials required

Login:password where the login is always empty and the password is the API key

Field	Required	Secret	Description
API Key	Yes	Yes	To use the Lemlist API, you will need to provide a personal API key.

Create a credential in Nexla

1. To create a new Lemlist credential, after selecting the data source/destination type, click the Add Credential tile to open the Add New Credential overlay.

New Credential Overlay – Lemlist

2. Enter a name for the credential in the Credential Name field and a short, meaningful description in the Credential Description field.

3. Lemlist uses Basic Authentication for all API requests. Enter your Lemlist API key in the API Key field. This is the personal API key you obtained from your Lemlist account settings. The API key is used as the password in Basic Authentication, with an empty username. The API key is sent in the Authorization header using Basic Authentication for all API requests to the Lemlist API. The API key is sensitive information and must be kept confidential.

   Keep your API key secure and do not share it publicly. The API key provides access to your Lemlist account data and should be treated as sensitive information. Your Lemlist API key can be found in your Lemlist account settings (API Keys or API Settings section) where you manage API keys. The API key is used as the password in Basic Authentication, with an empty username. This authentication format is specific to Lemlist's API and must be used exactly as specified. If your API key is compromised, you should immediately regenerate it in your Lemlist account settings. For detailed information about obtaining and managing API keys, API authentication, and available endpoints, see the Lemlist API documentation and Lemlist API authentication documentation.

4. Click the Save button at the bottom of the overlay. The newly added credential will now appear in a tile on the Authenticate screen during data source/destination creation and can be selected for use with a new data source or destination.

Use as a data source

To create a new data flow, navigate to the Integrate section, and click the New Data Flow button. Select the Lemlist connector tile, then select the credential that will be used to connect to the Lemlist account, and click Next; or, create a new Lemlist credential for use in this flow.

Endpoint templates

Nexla provides pre-built templates that can be used to rapidly configure data sources to ingest data from common Lemlist endpoints. Select the endpoint from which this source will fetch data from the Endpoint pulldown menu. Available endpoint templates are listed in the expandable boxes below.

List Campaigns

List Campaigns

• This endpoint automatically retrieves the list of all campaigns from your Lemlist account. No additional configuration is required beyond selecting this endpoint template.
• The endpoint uses GET requests to https://api.lemlist.com/api/campaigns?limit=100. The endpoint URL includes a default limit of 100 records per page.
• The endpoint uses pagination (iteration.type: paging.incrementing.offset) to retrieve all campaigns. Pagination starts from offset 0 and uses the offset query parameter to navigate through pages. The limit parameter controls how many records are returned per page, with an expected 100 records per page. The endpoint will automatically fetch all pages until all campaigns are retrieved.
• The response data path is $[*], which extracts all campaign objects from the response array in the API response.

This endpoint retrieves a list of all campaigns from your Lemlist account. The endpoint requires Basic Authentication with your API key (used as the password with an empty username), which is handled automatically by your credential configuration. The endpoint supports pagination through the offset and limit parameters, which allows you to retrieve large lists of campaigns efficiently. For detailed information about listing campaigns, pagination, and API response formats, see the Lemlist API documentation.

Get Activities

Get Activities

• This endpoint automatically retrieves activities from your Lemlist account. No additional configuration is required beyond selecting this endpoint template.
• The endpoint uses GET requests to https://api.lemlist.com/api/activities?limit=100. The endpoint URL includes a default limit of 100 records per page.
• The endpoint uses pagination (iteration.type: paging.incrementing.offset) to retrieve all activities. Pagination starts from offset 0 and uses the offset query parameter to navigate through pages. The limit parameter controls how many records are returned per page, with an expected 100 records per page. The endpoint will automatically fetch all pages until all activities are retrieved.
• The response data path is $[*], which extracts all activity objects from the response array in the API response.

This endpoint retrieves activities from your Lemlist account. The endpoint requires Basic Authentication with your API key (used as the password with an empty username), which is handled automatically by your credential configuration. The endpoint supports pagination through the offset and limit parameters, which allows you to retrieve large lists of activities efficiently. For detailed information about getting activities, pagination, and API response formats, see the Lemlist API documentation.

List Unsubscribes

List Unsubscribes

• This endpoint automatically retrieves the list of all people who are unsubscribed from your Lemlist account. No additional configuration is required beyond selecting this endpoint template.
• The endpoint uses GET requests to https://api.lemlist.com/api/unsubscribes?limit=100. The endpoint URL includes a default limit of 100 records per page.
• The endpoint uses pagination (iteration.type: paging.incrementing.offset) to retrieve all unsubscribes. Pagination starts from offset 0 and uses the offset query parameter to navigate through pages. The limit parameter controls how many records are returned per page, with an expected 100 records per page. The endpoint will automatically fetch all pages until all unsubscribes are retrieved.
• The response data path is $[*], which extracts all unsubscribe objects from the response array in the API response.

This endpoint retrieves a list of all people who are unsubscribed from your Lemlist account. The endpoint requires Basic Authentication with your API key (used as the password with an empty username), which is handled automatically by your credential configuration. The endpoint supports pagination through the offset and limit parameters, which allows you to retrieve large lists of unsubscribes efficiently. For detailed information about listing unsubscribes, pagination, and API response formats, see the Lemlist API documentation.

List Hooks

List Hooks

• This endpoint automatically retrieves the list of all hooks from your Lemlist account. No additional configuration is required beyond selecting this endpoint template.
• The endpoint uses GET requests to https://api.lemlist.com/api/hooks. The endpoint URL does not include pagination parameters.
• The endpoint does not use pagination (iteration.type: static.url), so it will fetch all hooks in a single request. The response data path is $[*], which extracts all hook objects from the response array in the API response.

This endpoint retrieves a list of all hooks from your Lemlist account. The endpoint requires Basic Authentication with your API key (used as the password with an empty username), which is handled automatically by your credential configuration. The endpoint does not support pagination, so all hooks are returned in a single request. For detailed information about listing hooks and API response formats, see the Lemlist API documentation.

Once the selected endpoint template has been configured, click the Test button to the right of the endpoint selection menu to retrieve a sample of the data that will be fetched. Sample data will be displayed in the Endpoint Test Result panel on the right, allowing you to verify that the source is configured correctly before saving.

Manual configuration

Lemlist data sources can also be manually configured to ingest data from any valid Lemlist API endpoint, including endpoints not covered by the pre-built templates or custom API configurations. Select the Advanced tab at the top of the configuration screen, and follow the instructions in Connect to Any API to configure the content format, endpoint URL, date/time and lookup macros, path to data, metadata, and request headers.

The Lemlist API typically returns data in JSON format. Lemlist API endpoints typically follow the pattern https://api.lemlist.com/api/{endpoint_path}. Ensure the API endpoint URL is correct and accessible with your current credentials; the endpoint requires Basic Authentication with your API key (used as the password with an empty username), which is handled automatically by your credential configuration. For detailed information about Lemlist API endpoints, see the Lemlist API documentation.

Once all of the relevant settings have been configured, click the Create button in the upper right corner of the screen to save and create the new Lemlist data source. Nexla will now begin ingesting data from the configured endpoint and will organize any data that it finds into one or more Nexsets.

Use as a destination

Click the + icon on the Nexset that will be sent to the Lemlist destination, and select the Send to Destination option from the menu. Select the Lemlist connector from the list of available destination connectors, then select the credential that will be used to connect to the Lemlist account, and click Next; or, create a new Lemlist credential for use in this flow.

Endpoint templates

Nexla provides pre-built templates that can be used to rapidly configure destinations to send data to common Lemlist endpoints. Select the endpoint to which data will be sent from the Endpoint pulldown menu. Then, click on the template in the list below to expand it, and follow the instructions to configure additional endpoint settings.

Add a Lead in a Campaign

Add a Lead in a Campaign

• Enter the ID of the campaign to which you want to add the lead in the Campaign ID field. This is the unique identifier for a specific campaign in your Lemlist account. You can obtain Campaign IDs from the "List Campaigns" endpoint or from your Lemlist account dashboard.
• Optionally, enter the email address of the lead in the Email field. If the email is not provided, it will be extracted from the Nexset data. If the lead doesn't exist, it will be created, then inserted into the campaign.
• The endpoint uses POST requests to https://api.lemlist.com/api/campaigns/{campaign_id}/leads/{email} where {campaign_id} is the Campaign ID you configured and {email} is the Email you specified or extracted from the Nexset. The endpoint URL is automatically constructed based on your configuration.
• The endpoint sends data from your Nexset as the request body in JSON format. The request body is automatically formatted according to the schema fields and data mapping you configure. Each record in your Nexset will be sent as a JSON object containing the lead data to add.

The request body must be properly formatted JSON that matches the Lemlist API specification for adding leads. The endpoint requires Basic Authentication with your API key (used as the password with an empty username), which is handled automatically by your credential configuration. The Content-Type: application/json header is automatically included in requests. If the lead doesn't exist, it will be created automatically, then inserted into the campaign. For detailed information about adding leads to campaigns, including required fields, field names, and request formats, see the Lemlist API documentation.

Unsubscribe

Unsubscribe

• Enter the email address or domain to unsubscribe in the Email or Domain field. If this is a domain, it must start with @ (e.g., @example.com). This will add the email address or domain to the unsubscribes list in your Lemlist account.
• The endpoint uses POST requests to https://api.lemlist.com/api/unsubscribes/{email} where {email} is the Email or Domain you configured. The endpoint URL is automatically constructed based on your configuration.
• The endpoint sends data from your Nexset as the request body in JSON format. The request body is automatically formatted according to the schema fields and data mapping you configure. Each record in your Nexset will be sent as a JSON object containing the unsubscribe data.

The request body must be properly formatted JSON that matches the Lemlist API specification for unsubscribing. The endpoint requires Basic Authentication with your API key (used as the password with an empty username), which is handled automatically by your credential configuration. The Content-Type: application/json header is automatically included in requests. If you're unsubscribing a domain, it must start with @ (e.g., @example.com). For detailed information about unsubscribing email addresses or domains, including required fields, field names, and request formats, see the Lemlist API documentation.

Add Hook

Add Hook

• This endpoint automatically adds a hook to your Lemlist account using data from your Nexset. No additional configuration is required beyond selecting this endpoint template.
• The endpoint uses POST requests to https://api.lemlist.com/api/hooks. The endpoint URL is fixed and does not require any path parameters.
• The endpoint sends data from your Nexset as the request body in JSON format. The request body is automatically formatted according to the schema fields and data mapping you configure. Each record in your Nexset will be sent as a JSON object containing the hook data to add.

The request body must be properly formatted JSON that matches the Lemlist API specification for adding hooks. The endpoint requires Basic Authentication with your API key (used as the password with an empty username), which is handled automatically by your credential configuration. The Content-Type: application/json header is automatically included in requests. For detailed information about adding hooks, including required fields, field names, and request formats, see the Lemlist API documentation.

Manual configuration

Lemlist destinations can also be manually configured to send data to any valid Lemlist API endpoint, including endpoints not covered by the pre-built templates or custom API configurations. Select the Advanced tab at the top of the configuration screen, and follow the instructions in Connect to Any API to configure the content format, endpoint URL, request headers, attribute exclusions, record batching, and response webhooks.

The Lemlist API typically uses JSON format for request bodies. Lemlist API endpoints typically follow the pattern https://api.lemlist.com/api/{endpoint_path}. Ensure the API endpoint URL is correct and accessible with your current credentials; the endpoint requires Basic Authentication with your API key (used as the password with an empty username), which is handled automatically by your credential configuration. For detailed information about Lemlist API endpoints, see the Lemlist API documentation.

Save & activate

Once all endpoint settings have been configured, click the Done button in the upper right corner of the screen to save and create the destination. To send the data to the configured Lemlist endpoint, open the destination resource menu, and select Activate.

The Nexset data will not be sent to the Lemlist endpoint until the destination is activated. Destinations can be activated immediately or at a later time, providing full control over data movement.