curl --request PATCH \
  --url https://api2.endstate.io/v1/units/{unit_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "external_id": "unit-002",
  "attributes": {
    "serial": "SN-0002"
  }
}
'

import requests

url = "https://api2.endstate.io/v1/units/{unit_id}"

payload = {
    "external_id": "unit-002",
    "attributes": { "serial": "SN-0002" }
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.patch(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'PATCH',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({external_id: 'unit-002', attributes: {serial: 'SN-0002'}})
};

fetch('https://api2.endstate.io/v1/units/{unit_id}', 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://api2.endstate.io/v1/units/{unit_id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => json_encode([
    'external_id' => 'unit-002',
    'attributes' => [
        'serial' => 'SN-0002'
    ]
  ]),
  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://api2.endstate.io/v1/units/{unit_id}"

	payload := strings.NewReader("{\n  \"external_id\": \"unit-002\",\n  \"attributes\": {\n    \"serial\": \"SN-0002\"\n  }\n}")

	req, _ := http.NewRequest("PATCH", 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.patch("https://api2.endstate.io/v1/units/{unit_id}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"external_id\": \"unit-002\",\n  \"attributes\": {\n    \"serial\": \"SN-0002\"\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api2.endstate.io/v1/units/{unit_id}")

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

request = Net::HTTP::Patch.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"external_id\": \"unit-002\",\n  \"attributes\": {\n    \"serial\": \"SN-0002\"\n  }\n}"

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

{
  "id": "33333333-3333-3333-3333-333333333333",
  "external_id": "unit-002",
  "name": "Example Unit",
  "description": null,
  "attributes": {
    "serial": "SN-0002"
  },
  "created_at": "2026-05-16T12:00:00.000Z",
  "redirect_url": null,
  "collection": {
    "id": "8e1a7f50-90ab-4cde-8012-3456789abcde",
    "name": "Example Collection",
    "external_id": "collection-001",
    "contract": {
      "address": "0x1111111111111111111111111111111111111111",
      "chain_id": 84532,
      "status": "active"
    },
    "token": {
      "status": "active",
      "serial": 5
    }
  },
  "chips": []
}

{
  "error": {
    "code": "validation.failed",
    "message": "The request failed schema validation. See `error.details` for per-field issues.",
    "request_id": "req_8e1a7f50-90ab-4cde-f012-3456789abcde",
    "doc_url": "https://docs.endstate.io/errors/validation-failed"
  }
}

{
  "error": {
    "code": "auth.unauthorized",
    "message": "Credential is missing or malformed.",
    "request_id": "req_8e1a7f50-90ab-4cde-f012-3456789abcde",
    "doc_url": "https://docs.endstate.io/errors/auth-unauthorized"
  }
}

{
  "error": {
    "code": "auth.forbidden",
    "message": "Credential is valid but does not have access to the requested resource or action.",
    "request_id": "req_8e1a7f50-90ab-4cde-f012-3456789abcde",
    "doc_url": "https://docs.endstate.io/errors/auth-forbidden"
  }
}

{
  "error": {
    "code": "unit.not_found",
    "message": "The unit ID does not exist in your organization.",
    "request_id": "req_8e1a7f50-90ab-4cde-f012-3456789abcde",
    "doc_url": "https://docs.endstate.io/errors/unit-not-found"
  }
}

{
  "error": {
    "code": "unit.already_exists",
    "message": "A unit with the supplied `external_id` already exists in the credential's environment.",
    "request_id": "req_8e1a7f50-90ab-4cde-f012-3456789abcde",
    "doc_url": "https://docs.endstate.io/errors/unit-already-exists"
  }
}

{
  "error": {
    "code": "rate_limit.exceeded",
    "message": "Per-key rate limit exceeded.",
    "request_id": "req_8e1a7f50-90ab-4cde-f012-3456789abcde",
    "doc_url": "https://docs.endstate.io/errors/rate-limit-exceeded"
  }
}

{
  "error": {
    "code": "internal.error",
    "message": "An unexpected server error occurred. Retry with exponential backoff and include `request_id` in any support request.",
    "request_id": "req_8e1a7f50-90ab-4cde-f012-3456789abcde",
    "doc_url": "https://docs.endstate.io/errors/internal-error"
  }
}