Lemlist

Lemlist

Access the Lemlist API with managed OAuth authentication. Manage campaigns, leads, activities, schedules, sequences, and unsubscribes for sales automation and cold outreach.

Quick Start

# List campaigns
python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/lemlist/api/campaigns')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Base URL

https://api.maton.ai/lemlist/api/{resource}

Maton proxies requests to api.lemlist.com/api and automatically injects your OAuth token.

Authentication

All requests require the Maton API key in the Authorization header:

Authorization: Bearer $MATON_API_KEY

Environment Variable: Set your API key as MATON_API_KEY:

export MATON_API_KEY="YOUR_API_KEY"

Getting Your API Key

1. Sign in or create an account at maton.ai 2. Go to maton.ai/settings 3. Copy your API key

Connection Management

Manage your Lemlist OAuth connections at https://api.maton.ai.

List Connections

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections?app=lemlist&status=ACTIVE')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Create Connection

python <<'EOF'
import urllib.request, os, json
data = json.dumps({'app': 'lemlist'}).encode()
req = urllib.request.Request('https://api.maton.ai/connections', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Get Connection

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections/{connection_id}')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Response:

{
  "connection": {
    "connection_id": "{connection_id}",
    "status": "ACTIVE",
    "creation_time": "2026-02-12T02:00:53.023887Z",
    "last_updated_time": "2026-02-12T02:01:45.284131Z",
    "url": "https://connect.maton.ai/?session_token=...",
    "app": "lemlist",
    "metadata": {}
  }
}

Open the returned url in a browser to complete OAuth authorization.

Delete Connection

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections/{connection_id}', method='DELETE')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Specifying Connection

If you have multiple Lemlist connections, specify which one to use with the Maton-Connection header:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/lemlist/api/campaigns')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Maton-Connection', '{connection_id}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

If you have multiple connections, always include this header to ensure requests go to the intended account.

Security & Permissions

API Reference

Team

#### Get Team

GET /lemlist/api/team

Returns team information including user IDs and settings.

#### Get Team Credits

GET /lemlist/api/team/credits

Returns remaining credits balance.

#### Get Team Senders

GET /lemlist/api/team/senders

Returns all team members and their associated campaigns.

Campaigns

#### List Campaigns

GET /lemlist/api/campaigns

#### Create Campaign

POST /lemlist/api/campaigns
Content-Type: application/json
{
  "name": "My Campaign"
}

Creates a new campaign with an empty sequence and default schedule automatically added.

#### Get Campaign

GET /lemlist/api/campaigns/{campaignId}

#### Update Campaign

PATCH /lemlist/api/campaigns/{campaignId}
Content-Type: application/json
{
  "name": "Updated Campaign Name"
}

#### Pause Campaign

POST /lemlist/api/campaigns/{campaignId}/pause

Pauses a running campaign.

Campaign Sequences

#### Get Campaign Sequences

GET /lemlist/api/campaigns/{campaignId}/sequences

Returns all sequences and steps for a campaign.

Campaign Schedules

#### Get Campaign Schedules

GET /lemlist/api/campaigns/{campaignId}/schedules

Returns all schedules associated with a campaign.

Leads

#### Add Lead to Campaign

POST /lemlist/api/campaigns/{campaignId}/leads
Content-Type: application/json
{
  "email": "lead@example.com",
  "firstName": "John",
  "lastName": "Doe",
  "companyName": "Acme Inc"
}

Creates a new lead and adds it to the campaign. If the lead already exists, it will be inserted into the campaign.

#### Get Lead by Email

GET /lemlist/api/leads/{email}

#### Update Lead in Campaign

PATCH /lemlist/api/campaigns/{campaignId}/leads/{email}
Content-Type: application/json
{
  "firstName": "Jane",
  "lastName": "Smith"
}

#### Delete Lead from Campaign

DELETE /lemlist/api/campaigns/{campaignId}/leads/{email}

Activities

#### List Activities

GET /lemlist/api/activities

Returns the history of campaign activities (last 100 activities).

Query parameters:

Schedules

#### List Schedules

GET /lemlist/api/schedules

Returns all schedules with pagination.

Response:

{
  "schedules": [...],
  "pagination": {
    "totalRecords": 10,
    "currentPage": 1,
    "nextPage": 2,
    "totalPage": 2
  }
}

#### Create Schedule

POST /lemlist/api/schedules
Content-Type: application/json
{
  "name": "Business Hours",
  "timezone": "America/New_York",
  "start": "09:00",
  "end": "17:00",
  "weekdays": [1, 2, 3, 4, 5]
}

Weekdays: 0 = Sunday, 1 = Monday, ..., 6 = Saturday

#### Get Schedule

GET /lemlist/api/schedules/{scheduleId}

#### Update Schedule

PATCH /lemlist/api/schedules/{scheduleId}
Content-Type: application/json
{
  "name": "Updated Schedule",
  "start": "08:00",
  "end": "18:00"
}

#### Delete Schedule

DELETE /lemlist/api/schedules/{scheduleId}

Companies

#### List Companies

GET /lemlist/api/companies

Returns companies with pagination.

Response:

{
  "data": [...],
  "total": 100
}

Unsubscribes

#### List Unsubscribes

GET /lemlist/api/unsubscribes

Returns all unsubscribed emails and domains.

#### Add Unsubscribe

POST /lemlist/api/unsubscribes
Content-Type: application/json
{
  "email": "unsubscribe@example.com"
}

Can also add domains by using a domain value.

Inbox Labels

#### List Labels

GET /lemlist/api/inbox/labels

Returns all labels available to the team.

Pagination

Lemlist uses page-based pagination with different formats depending on the endpoint:

Schedules format:

{
  "schedules": [...],
  "pagination": {
    "totalRecords": 100,
    "currentPage": 1,
    "nextPage": 2,
    "totalPage": 10
  }
}

Companies format:

{
  "data": [...],
  "total": 100
}

Code Examples

JavaScript - List Campaigns

const response = await fetch(
  'https://api.maton.ai/lemlist/api/campaigns',
  {
    headers: {
      'Authorization': Bearer ${process.env.MATON_API_KEY}
    }
  }
);
const campaigns = await response.json();
console.log(campaigns);

Python - List Campaigns

import os
import requests
response = requests.get(
    'https://api.maton.ai/lemlist/api/campaigns',
    headers={'Authorization': f'Bearer {os.environ["MATON_API_KEY"]}'}
)
campaigns = response.json()
for campaign in campaigns:
    print(f"{campaign['name']}: {campaign['_id']}")

Python - Create Campaign and Add Lead

import os
import requests
headers = {'Authorization': f'Bearer {os.environ["MATON_API_KEY"]}'}
base_url = 'https://api.maton.ai/lemlist/api'
Create campaign
campaign_response = requests.post(
    f'{base_url}/campaigns',
    headers=headers,
    json={'name': 'Q1 Outreach'}
)
campaign = campaign_response.json()
print(f"Created campaign: {campaign['_id']}")
Add lead to campaign
lead_response = requests.post(
    f'{base_url}/campaigns/{campaign["_id"]}/leads',
    headers=headers,
    json={
        'email': 'prospect@example.com',
        'firstName': 'John',
        'lastName': 'Doe',
        'companyName': 'Acme Corp'
    }
)
lead = lead_response.json()
print(f"Added lead: {lead['_id']}")

Notes

Rate Limits

| Operation | Limit | |-----------|-------| | API calls | 20 per 2 seconds per API key |

When rate limited, implement exponential backoff for retries.

Error Handling

| Status | Meaning | |--------|---------| | 400 | Bad request or missing Lemlist connection | | 401 | Invalid or missing Maton API key | | 404 | Resource not found | | 405 | Method not allowed | | 422 | Validation error | | 429 | Rate limited | | 4xx/5xx | Passthrough error from Lemlist API |

Troubleshooting: API Key Issues

1. Check that the MATON_API_KEY environment variable is set:

echo $MATON_API_KEY

2. Verify the API key is valid by listing connections:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Troubleshooting: Invalid App Name

1. Ensure your URL path starts with lemlist. For example:

Resources

# List campaigns
python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/lemlist/api/campaigns')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF