Get a session

Returns the session’s state, its model, the tracks and commands the model declares, and, once it has ended, why.

Any developer or account_admin of the account the session runs under can read it, not only the user who started it. A session on another account, or an unknown ID, answers 403. A session token reads only the sessions bound to it.

capabilities, selected_transport, and generation appear once the session reaches WAITING. environment and revision are returned only to members of the account that owns the model. ended appears once the session is closed.

Session states: CREATED (accepted, being placed), PENDING (placed, waiting for a client), WAITING (offer received, answer pending), SUSPENDED (waiting for capacity), ACTIVE (a client is connected and the model is running), INACTIVE (the client disconnected), CLOSED (ended; cannot be reused).

GET

sessions

{session_id}

Get a session

curl --request GET \
  --url https://api.reactor.inc/sessions/{session_id} \
  --header 'Authorization: Bearer <token>'

const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};

fetch('https://api.reactor.inc/sessions/{session_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://api.reactor.inc/sessions/{session_id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.reactor.inc/sessions/{session_id}"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

require 'uri'
require 'net/http'

url = URI("https://api.reactor.inc/sessions/{session_id}")

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

request = Net::HTTP::Get.new(url)
request["Authorization"] = 'Bearer <token>'

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

{
  "session_id": "85ded560-014c-42df-8902-89dfbca8fa00",
  "server_info": {
    "server_version": "1.5.11"
  },
  "selected_transport": {
    "protocol": "webrtc",
    "version": "1.0"
  },
  "model": {
    "name": "reactor/helios",
    "version": "1.4.0"
  },
  "capabilities": {
    "protocol_version": "1.0",
    "tracks": [
      {
        "name": "main_video",
        "kind": "video",
        "direction": "recvonly"
      },
      {
        "name": "webcam",
        "kind": "video",
        "direction": "sendonly"
      }
    ],
    "emission_fps": 30
  },
  "generation": "streamed",
  "machine_id": "inst-7f9c2d",
  "state": "ACTIVE",
  "cluster": "054e2495-c685-450f-9ceb-57f185b7300a",
  "zone": "us-west",
  "region": "us-west",
  "origin_country": "US",
  "user_id": "0d7a1c4e-5b2f-4a6d-8e9c-1f3b5d7e9a2c",
  "closed": false,
  "created_at": "2026-11-04T09:30:00Z",
  "updated_at": "2026-11-04T09:31:12Z"
}

Authorizations

Authorization

string

header

required

A Reactor API key (rk_...), sent as Authorization: Bearer rk_.... Keep it on a server.

Headers

Reactor-API-Version

string

The API protocol version the client speaks. Currently 1. Older versions than the server's minimum get 426.

Example:

"1"

Path Parameters

session_id

string<uuid>

required

The session's ID, as returned by POST /sessions.

Response

The session.

session_id

string<uuid>

required

state

enum<string>

required

The session's lifecycle state.

Available options:

CREATED,

PENDING,

WAITING,

SUSPENDED,

ACTIVE,

INACTIVE,

CLOSED

closed

boolean

required

Whether the session has ended.

cluster

string

required

An opaque placement ID. "" until the session is placed.

user_id

string<uuid>

required

The user who started the session. Can be another member of your account.

created_at

string<date-time>

required

updated_at

string<date-time>

required

The last time the session record changed.

model

object

Show child attributes

server_info

object

Show child attributes

selected_transport

object

Show child attributes

capabilities

object

What the model declares for this session, reported by its runtime.

Show child attributes

generation

enum<string>

The mode the model runs the session in. Appears once the session is WAITING, and is absent for a runtime that predates generation modes (such a session streams).

Available options:

streamed,

stepped

zone

string

The Reactor region serving the session. Omitted when unknown.

region

string

The Reactor region that served the session, such as us-west. Omitted when unknown.

origin_country

string

The ISO 3166-1 alpha-2 country the session was started from, when known.

Example:

"US"

machine_id

string

An opaque ID of the instance serving the session. Absent until an instance picks it up.

ended

object

Why and when the session ended. Present only once the session is closed.

Show child attributes

environment

object

The environment the session targets. Returned only to members of the account that owns the model.

Show child attributes

revision

object

The environment revision that served the session. Returned only to members of the account that owns the model.

Show child attributes

⌘I

Get a session

curl --request GET \
  --url https://api.reactor.inc/sessions/{session_id} \
  --header 'Authorization: Bearer <token>'

const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};

fetch('https://api.reactor.inc/sessions/{session_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://api.reactor.inc/sessions/{session_id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.reactor.inc/sessions/{session_id}"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

require 'uri'
require 'net/http'

url = URI("https://api.reactor.inc/sessions/{session_id}")

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

request = Net::HTTP::Get.new(url)
request["Authorization"] = 'Bearer <token>'

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

{
  "session_id": "85ded560-014c-42df-8902-89dfbca8fa00",
  "server_info": {
    "server_version": "1.5.11"
  },
  "selected_transport": {
    "protocol": "webrtc",
    "version": "1.0"
  },
  "model": {
    "name": "reactor/helios",
    "version": "1.4.0"
  },
  "capabilities": {
    "protocol_version": "1.0",
    "tracks": [
      {
        "name": "main_video",
        "kind": "video",
        "direction": "recvonly"
      },
      {
        "name": "webcam",
        "kind": "video",
        "direction": "sendonly"
      }
    ],
    "emission_fps": 30
  },
  "generation": "streamed",
  "machine_id": "inst-7f9c2d",
  "state": "ACTIVE",
  "cluster": "054e2495-c685-450f-9ceb-57f185b7300a",
  "zone": "us-west",
  "region": "us-west",
  "origin_country": "US",
  "user_id": "0d7a1c4e-5b2f-4a6d-8e9c-1f3b5d7e9a2c",
  "closed": false,
  "created_at": "2026-11-04T09:30:00Z",
  "updated_at": "2026-11-04T09:31:12Z"
}

Get started

SDK Reference

CLI Reference

Platform API Reference

Endpoints

Get a session

Authorizations

Headers

Path Parameters

Response