curl --request GET \
  --url https://api.lemlist.com/api/contacts/{idOrEmail} \
  --header 'Authorization: Basic <encoded-value>'

{
  "_id": "ctc_Rofmb6uNGyaPNZ2ni",
  "teamId": "tea_b4rMsi2trB42WyuWP",
  "fullName": "Bastien Velitchkine",
  "email": "support@lemlist.com",
  "fields": {
    "firstName": "Bastien",
    "jobTitle": "Growth Engineer",
    "lastName": "Velitchkine",
    "industry": "Technology",
    "isActiveInCampaigns": false,
    "lastCampaign": "NEW TO DELETE",
    "lastLeadMarkedAsInterestedDate": "2025-10-28T02:12:31.971Z",
    "leadStatus": "Marked as not Interested by api"
  },
  "campaigns": [
    {
      "campaignId": "cam_9NsHPnykWESTncCW8",
      "campaignState": "running",
      "leadState": "review",
      "leadId": "lea_mizMsAEkRrJuhouYe"
    }
  ],
  "ownerId": "usr_gmHgNGRcGPSTJrDbT",
  "createdAt": "2025-10-28T00:40:37.917Z",
  "createdBy": "usr_gmHgNGRcGPSTJrDbT"
}