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

Replace {resource} with the actual Lemlist API endpoint path. The gateway 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://ctrl.maton.ai.

List Connections

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://ctrl.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://ctrl.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://ctrl.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": "3ecf268f-42ad-40cc-b77a-25e020fbf591",
    "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://ctrl.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://gateway.maton.ai/lemlist/api/campaigns')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Maton-Connection', '3ecf268f-42ad-40cc-b77a-25e020fbf591')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

If omitted, the gateway uses the default (oldest) active connection.

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:

• campaignId - Filter by campaign
• type - Filter by activity type (emailsSent, emailsOpened, emailsClicked, etc.)

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://gateway.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://gateway.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://gateway.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

• Campaign IDs start with cam_
• Lead IDs start with lea_
• Schedule IDs start with skd_
• Sequence IDs start with seq_
• Team IDs start with tea_
• User IDs start with usr_
• Campaigns cannot be deleted via API (only paused)
• When creating a campaign, an empty sequence and default schedule are automatically added
• Lead emails are used as identifiers for lead operations
• IMPORTANT: When using curl commands, use curl -g when URLs contain brackets to disable glob parsing
• IMPORTANT: When piping curl output to jq, environment variables may not expand correctly. Use Python examples instead.

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://ctrl.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:

• Correct: https://gateway.maton.ai/lemlist/api/campaigns
• Incorrect: https://gateway.maton.ai/api/campaigns

Resources

• Lemlist API Documentation
• Lemlist API Reference
• Lemlist Help Center - API
• Maton Community
• Maton Support