Create a unit

curl --request POST \
  --url https://api2.endstate.io/v1/units \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "external_id": "unit-001",
  "name": "Example Unit",
  "attributes": {
    "custom_attribute": "value"
  },
  "collection_id": "8e1a7f50-90ab-4cde-8012-3456789abcde"
}
'

import requests

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

payload = {
    "external_id": "unit-001",
    "name": "Example Unit",
    "attributes": { "custom_attribute": "value" },
    "collection_id": "8e1a7f50-90ab-4cde-8012-3456789abcde"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    external_id: 'unit-001',
    name: 'Example Unit',
    attributes: {custom_attribute: 'value'},
    collection_id: '8e1a7f50-90ab-4cde-8012-3456789abcde'
  })
};

fetch('https://api2.endstate.io/v1/units', 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",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'external_id' => 'unit-001',
    'name' => 'Example Unit',
    'attributes' => [
        'custom_attribute' => 'value'
    ],
    'collection_id' => '8e1a7f50-90ab-4cde-8012-3456789abcde'
  ]),
  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"

	payload := strings.NewReader("{\n  \"external_id\": \"unit-001\",\n  \"name\": \"Example Unit\",\n  \"attributes\": {\n    \"custom_attribute\": \"value\"\n  },\n  \"collection_id\": \"8e1a7f50-90ab-4cde-8012-3456789abcde\"\n}")

	req, _ := http.NewRequest("POST", 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.post("https://api2.endstate.io/v1/units")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"external_id\": \"unit-001\",\n  \"name\": \"Example Unit\",\n  \"attributes\": {\n    \"custom_attribute\": \"value\"\n  },\n  \"collection_id\": \"8e1a7f50-90ab-4cde-8012-3456789abcde\"\n}")
  .asString();

require 'uri'
require 'net/http'

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

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"external_id\": \"unit-001\",\n  \"name\": \"Example Unit\",\n  \"attributes\": {\n    \"custom_attribute\": \"value\"\n  },\n  \"collection_id\": \"8e1a7f50-90ab-4cde-8012-3456789abcde\"\n}"

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

{
  "id": "33333333-3333-3333-3333-333333333333",
  "external_id": "unit-001",
  "name": "Example Unit",
  "attributes": {
    "custom_attribute": "value"
  },
  "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": "pending",
      "serial": null
    }
  },
  "chips": []
}

POST

units

Create a unit

curl --request POST \
  --url https://api2.endstate.io/v1/units \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "external_id": "unit-001",
  "name": "Example Unit",
  "attributes": {
    "custom_attribute": "value"
  },
  "collection_id": "8e1a7f50-90ab-4cde-8012-3456789abcde"
}
'

import requests

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

payload = {
    "external_id": "unit-001",
    "name": "Example Unit",
    "attributes": { "custom_attribute": "value" },
    "collection_id": "8e1a7f50-90ab-4cde-8012-3456789abcde"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    external_id: 'unit-001',
    name: 'Example Unit',
    attributes: {custom_attribute: 'value'},
    collection_id: '8e1a7f50-90ab-4cde-8012-3456789abcde'
  })
};

fetch('https://api2.endstate.io/v1/units', 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",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'external_id' => 'unit-001',
    'name' => 'Example Unit',
    'attributes' => [
        'custom_attribute' => 'value'
    ],
    'collection_id' => '8e1a7f50-90ab-4cde-8012-3456789abcde'
  ]),
  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"

	payload := strings.NewReader("{\n  \"external_id\": \"unit-001\",\n  \"name\": \"Example Unit\",\n  \"attributes\": {\n    \"custom_attribute\": \"value\"\n  },\n  \"collection_id\": \"8e1a7f50-90ab-4cde-8012-3456789abcde\"\n}")

	req, _ := http.NewRequest("POST", 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.post("https://api2.endstate.io/v1/units")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"external_id\": \"unit-001\",\n  \"name\": \"Example Unit\",\n  \"attributes\": {\n    \"custom_attribute\": \"value\"\n  },\n  \"collection_id\": \"8e1a7f50-90ab-4cde-8012-3456789abcde\"\n}")
  .asString();

require 'uri'
require 'net/http'

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

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"external_id\": \"unit-001\",\n  \"name\": \"Example Unit\",\n  \"attributes\": {\n    \"custom_attribute\": \"value\"\n  },\n  \"collection_id\": \"8e1a7f50-90ab-4cde-8012-3456789abcde\"\n}"

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

{
  "id": "33333333-3333-3333-3333-333333333333",
  "external_id": "unit-001",
  "name": "Example Unit",
  "attributes": {
    "custom_attribute": "value"
  },
  "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": "pending",
      "serial": null
    }
  },
  "chips": []
}

Authorizations

Authorization

string

header

required

Use Authorization: Bearer end_sk_* for partner API keys (e.g. end_sk_AbCd_example_api_key).

Headers

Idempotency-Key

string

Unique key that makes this request safe to retry. Replaying the key with the same body returns the original response with Idempotent-Replayed: true; replaying it with a different body returns 409 idempotency.key_conflict.

Required string length: 1 - 255

Example:

"a1b2c3d4-0000-4000-8000-000000000000"

Body

application/json

collection_id

string<uuid>

required

Collection this unit belongs to.

Example:

"8e1a7f50-90ab-4cde-8012-3456789abcde"

external_id

string

Unique identifier for the unit within your organization.

Required string length: 1 - 256

Example:

"unit-001"

name

string

Human-readable name for the unit.

Required string length: 1 - 256

Example:

"Example Unit"

attributes

object

Free-form JSON attributes for the unit.

Show child attributes

Example:

{ "custom_attribute": "value" }

redirect_url

string<uri> | null

Tap redirect URL for this unit. Omit or null for none.

Example:

"https://brand.example/p"

Response

Created unit.

string<uuid>

required

external_id

string | null

required

name

string | null

required

attributes

object | null

required

Show child attributes

created_at

string<date-time>

required

redirect_url

string<uri> | null

required

Tap redirect URL for this unit; takes precedence over product/collection/org defaults.

Example:

"https://brand.example/p"

collection

object | null

required

The unit's collection. Null only for units created before collections existed.

Show child attributes

chips

object[]

required

Chips paired to this unit.

Show child attributes

Overview

Endpoints

Create a unit

Authorizations

Headers

Body

Response