Add a recipient to a recipient list. Double opt-in processes will not be overwritten by other opt-in processes (see <a href="https://support.optimizely.com/hc/en-us/articles/4413192291981#prioritization">Opt-in documentation</a>).

curl --request POST \
     --url https://api.campaign.episerver.net/rest/{clientId}/recipients/{recipientListId} \
     --header 'accept: application/json' \
     --header 'content-type: application/x-www-form-urlencoded' \
     --data 'returnOptInMailId=boolean' \
     --data 'recipientId=string'

var myHeaders = new Headers();
myHeaders.append("accept", "application/json");
myHeaders.append("content-type", "application/x-www-form-urlencoded");

var urlencoded = new URLSearchParams();
urlencoded.append("returnOptInMailId", "boolean");
urlencoded.append("recipientId", "string");

var requestOptions = {
   method: 'POST',
   headers: myHeaders,
   body: urlencoded,
   redirect: 'follow'
};

fetch("https://api.campaign.episerver.net/rest/{clientId}/recipients/{recipientListId}", requestOptions)
   .then(response => response.text())
   .then(result => console.log(result))
   .catch(error => console.log('error', error));

require "uri"
require "net/http"

url = URI("https://api.campaign.episerver.net/rest/{clientId}/recipients/{recipientListId}")

https = Net::HTTP.new(url.host, url.port)
https.use_ssl = true

request = Net::HTTP::Post.new(url)
request["accept"] = "application/json"
request["content-type"] = "application/x-www-form-urlencoded"
request.body = "returnOptInMailId=boolean&recipientId=string"

response = https.request(request)
puts response.read_body

import requests

url = "https://api.campaign.episerver.net/rest/{clientId}/recipients/{recipientListId}"

payload = 'returnOptInMailId=boolean&recipientId=string'
headers = {
   'accept': 'application/json',
   'content-type': 'application/x-www-form-urlencoded'
}

response = requests.request("POST", url, headers=headers, data=payload)

print(response.text)

// The recipient was added successfully.
{
  "id": "",
  "created": "",
  "modified": "",
  "optInMailId": "",
  "links": [
    {
      "uriBuilder": {},
      "rels": [
        ""
      ],
      "rel": "",
      "type": "",
      "params": "",
      "title": "",
      "uri": ""
    }
  ]
}

// The recipient was added successfully, but is not immediately accessible (in case of a double opt-in).
{
  "id": "",
  "created": "",
  "modified": "",
  "optInMailId": "",
  "links": [
    {
      "uriBuilder": {},
      "rels": [
        ""
      ],
      "rel": "",
      "type": "",
      "params": "",
      "title": "",
      "uri": ""
    }
  ]
}

// The required parameters for the recipient's creation are not provided. Ensure that "clientId", "recipientListId" and "recipientId" are added to the request.

// The recipient has either been blacklisted, has exceeded the bounce limit, has unsubscribed, or exists already. Ensure that "recipientId" is correct and that the recipient does not meet any of the other criteria.