Contacts
Set one custom field
Set a single custom field on a contact by its slug (the field’s key). The slug must be a defined custom field in this workspace (create one with POST /custom-fields). Merges into the contact’s attributes without touching other fields. Requires contacts:write.
PUT
/
contacts
/
{id}
/
fields
/
{slug}
Set one custom field
curl --request PUT \
--url https://api.smartlyq.com/v1/contacts/{id}/fields/{slug} \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"value": "enterprise"
}
'import requests
url = "https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}"
payload = { "value": "enterprise" }
headers = {
"Authorization": "Bearer <token>",
"Content-Type": "application/json"
}
response = requests.put(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'PUT',
headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
body: JSON.stringify({value: 'enterprise'})
};
fetch('https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "PUT",
CURLOPT_POSTFIELDS => json_encode([
'value' => 'enterprise'
]),
CURLOPT_HTTPHEADER => [
"Authorization: Bearer <token>",
"Content-Type: application/json"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}"
payload := strings.NewReader("{\n \"value\": \"enterprise\"\n}")
req, _ := http.NewRequest("PUT", url, payload)
req.Header.Add("Authorization", "Bearer <token>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.put("https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}")
.header("Authorization", "Bearer <token>")
.header("Content-Type", "application/json")
.body("{\n \"value\": \"enterprise\"\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Put.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"value\": \"enterprise\"\n}"
response = http.request(request)
puts response.read_body{
"success": true,
"data": {
"attributes": {
"plan_tier": "enterprise"
}
}
}{
"success": false,
"error": {
"code": "RESOURCE_NOT_FOUND",
"message": "Post not found.",
"details": {}
},
"meta": {
"request_id": "req_9f3a2b1c-7d4e-4a08-b2c6-5e1f8a9d0c34",
"timestamp": "2026-07-26T09:41:22Z"
}
}{
"success": false,
"error": {
"code": "VALIDATION_ERROR",
"message": "Missing required fields: content, platforms.",
"details": {
"fields": [
"content",
"platforms"
]
}
},
"meta": {
"request_id": "req_9f3a2b1c-7d4e-4a08-b2c6-5e1f8a9d0c34",
"timestamp": "2026-07-26T09:41:22Z"
}
}Authorizations
API key from Developer dashboard (Bearer token).
Body
application/json
The value to store (string, number, boolean or null).
Response
Updated attributes
The response is of type object.
Previous
Clear one custom fieldRemove a single custom field from a contact by slug. Succeeds (200) even if the field was not set. Requires contacts:write.
Next
⌘I
Set one custom field
curl --request PUT \
--url https://api.smartlyq.com/v1/contacts/{id}/fields/{slug} \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"value": "enterprise"
}
'import requests
url = "https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}"
payload = { "value": "enterprise" }
headers = {
"Authorization": "Bearer <token>",
"Content-Type": "application/json"
}
response = requests.put(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'PUT',
headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
body: JSON.stringify({value: 'enterprise'})
};
fetch('https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "PUT",
CURLOPT_POSTFIELDS => json_encode([
'value' => 'enterprise'
]),
CURLOPT_HTTPHEADER => [
"Authorization: Bearer <token>",
"Content-Type: application/json"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}"
payload := strings.NewReader("{\n \"value\": \"enterprise\"\n}")
req, _ := http.NewRequest("PUT", url, payload)
req.Header.Add("Authorization", "Bearer <token>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.put("https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}")
.header("Authorization", "Bearer <token>")
.header("Content-Type", "application/json")
.body("{\n \"value\": \"enterprise\"\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.smartlyq.com/v1/contacts/{id}/fields/{slug}")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Put.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"value\": \"enterprise\"\n}"
response = http.request(request)
puts response.read_body{
"success": true,
"data": {
"attributes": {
"plan_tier": "enterprise"
}
}
}{
"success": false,
"error": {
"code": "RESOURCE_NOT_FOUND",
"message": "Post not found.",
"details": {}
},
"meta": {
"request_id": "req_9f3a2b1c-7d4e-4a08-b2c6-5e1f8a9d0c34",
"timestamp": "2026-07-26T09:41:22Z"
}
}{
"success": false,
"error": {
"code": "VALIDATION_ERROR",
"message": "Missing required fields: content, platforms.",
"details": {
"fields": [
"content",
"platforms"
]
}
},
"meta": {
"request_id": "req_9f3a2b1c-7d4e-4a08-b2c6-5e1f8a9d0c34",
"timestamp": "2026-07-26T09:41:22Z"
}
}
