Replace an environment

Replaces all of the environment’s settings in one atomic write and creates its next revision. Use it from a client that holds the full desired state, such as a CI job. It has the rules, status codes, and response of the update, with these differences:

image and instances are required. Nothing defaults from the environment or the model.
An omitted resources.accelerators is [], so it moves a GPU environment to CPU.
resources is a full object: an omitted cpu or memory value is unset.
variables is a full map: an omitted name is removed, and a null value is 400.

As on the update, an omitted weights keeps the current pin, and only null clears it.

PUT

projects

{proj_id}

environments

{env}

Replace an environment

curl --request PUT \
  --url https://api.reactor.inc/projects/{proj_id}/environments/{env} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "image": {
    "tag": "v1.4.0"
  },
  "resources": {
    "accelerators": [
      {
        "type": "NVIDIA_H100",
        "count": 1
      }
    ]
  },
  "instances": [
    {
      "count": 2
    }
  ],
  "variables": {
    "LOG_LEVEL": {
      "value": "info"
    },
    "API_KEY": {
      "secret": "API_KEY"
    }
  }
}
'

import requests

url = "https://api.reactor.inc/projects/{proj_id}/environments/{env}"

payload = {
    "image": { "tag": "v1.4.0" },
    "resources": { "accelerators": [
            {
                "type": "NVIDIA_H100",
                "count": 1
            }
        ] },
    "instances": [{ "count": 2 }],
    "variables": {
        "LOG_LEVEL": { "value": "info" },
        "API_KEY": { "secret": "API_KEY" }
    }
}
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({
    image: {tag: 'v1.4.0'},
    resources: {accelerators: [{type: 'NVIDIA_H100', count: 1}]},
    instances: [{count: 2}],
    variables: {LOG_LEVEL: {value: 'info'}, API_KEY: {secret: 'API_KEY'}}
  })
};

fetch('https://api.reactor.inc/projects/{proj_id}/environments/{env}', 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/projects/{proj_id}/environments/{env}",
  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([
    'image' => [
        'tag' => 'v1.4.0'
    ],
    'resources' => [
        'accelerators' => [
                [
                                'type' => 'NVIDIA_H100',
                                'count' => 1
                ]
        ]
    ],
    'instances' => [
        [
                'count' => 2
        ]
    ],
    'variables' => [
        'LOG_LEVEL' => [
                'value' => 'info'
        ],
        'API_KEY' => [
                'secret' => 'API_KEY'
        ]
    ]
  ]),
  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.reactor.inc/projects/{proj_id}/environments/{env}"

	payload := strings.NewReader("{\n  \"image\": {\n    \"tag\": \"v1.4.0\"\n  },\n  \"resources\": {\n    \"accelerators\": [\n      {\n        \"type\": \"NVIDIA_H100\",\n        \"count\": 1\n      }\n    ]\n  },\n  \"instances\": [\n    {\n      \"count\": 2\n    }\n  ],\n  \"variables\": {\n    \"LOG_LEVEL\": {\n      \"value\": \"info\"\n    },\n    \"API_KEY\": {\n      \"secret\": \"API_KEY\"\n    }\n  }\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.reactor.inc/projects/{proj_id}/environments/{env}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"image\": {\n    \"tag\": \"v1.4.0\"\n  },\n  \"resources\": {\n    \"accelerators\": [\n      {\n        \"type\": \"NVIDIA_H100\",\n        \"count\": 1\n      }\n    ]\n  },\n  \"instances\": [\n    {\n      \"count\": 2\n    }\n  ],\n  \"variables\": {\n    \"LOG_LEVEL\": {\n      \"value\": \"info\"\n    },\n    \"API_KEY\": {\n      \"secret\": \"API_KEY\"\n    }\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.reactor.inc/projects/{proj_id}/environments/{env}")

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  \"image\": {\n    \"tag\": \"v1.4.0\"\n  },\n  \"resources\": {\n    \"accelerators\": [\n      {\n        \"type\": \"NVIDIA_H100\",\n        \"count\": 1\n      }\n    ]\n  },\n  \"instances\": [\n    {\n      \"count\": 2\n    }\n  ],\n  \"variables\": {\n    \"LOG_LEVEL\": {\n      \"value\": \"info\"\n    },\n    \"API_KEY\": {\n      \"secret\": \"API_KEY\"\n    }\n  }\n}"

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

{
  "id": "4b5c6d7e-8f90-4a1b-8c2d-3e4f5a6b7c8d",
  "project_id": "0d3c6f4e-8a1b-4c2d-9e7f-1a2b3c4d5e6f",
  "name": "production",
  "image": {
    "tag": "v1.4.0",
    "digest": "sha256:9e01aa47c3b2d5f6e7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0",
    "ref": null
  },
  "weights": null,
  "resources": {
    "accelerators": [
      {
        "type": "NVIDIA_H100",
        "count": 1
      }
    ]
  },
  "extra_args": [],
  "node_selector": null,
  "instances": [
    {
      "count": 2
    }
  ],
  "variables": {
    "LOG_LEVEL": {
      "value": "info"
    },
    "API_KEY": {
      "secret": "API_KEY",
      "version_id": "018cc820-e222-7ba6-9f43-7cf0b7e3a112"
    }
  },
  "revision": {
    "number": 5,
    "created_by": {
      "user_id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d"
    },
    "created_at": "2026-10-11T08:00:00Z"
  },
  "public": false,
  "created_at": "2026-10-09T08:53:20Z",
  "deleted_at": null
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>"
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>"
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>"
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>"
}

{
  "error": "failed_precondition",
  "reason": "environment_incomplete",
  "message": "environment staging is not complete: set image",
  "missing_fields": [
    "image"
  ]
}

{
  "error": "etag_mismatch",
  "message": "environment staging is at revision 4, not 3"
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>",
  "quota_type": "<string>",
  "limit": "<string>",
  "current": "<string>",
  "field": "<string>"
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>"
}

Authorizations

Authorization

string

header

required

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

Headers

If-Match

string

The ETag of your last read, a revision number in quotes. If the environment's newest revision differs, the write is 412 etag_mismatch and nothing is written. A weak tag, a list, or * is 400.

Example:

"\"3\""

Path Parameters

proj_id

string<uuid>

required

The project's ID, a UUID. It is not the model's ID.

env

string

required

The environment's ID (a UUID) or its name, such as production. A name matches only a live environment; a deleted environment is reachable by its ID only.

Body

application/json

The full desired settings. Read-only fields are accepted only with their current values.

image

object

required

The image to run. Send tag, ref, both (they must name the same image), or digest alone. A tag is a model image tag, or a release of the model; a tag wins over a release of the same name. A 12 to 64 character lowercase hex tag that no tag has names the image whose digest it starts. A digest is sha256:<64 hex> or a 12+ character hex prefix. A ref, a digest, or such a hex tag runs the image with no release.

Show child attributes

instances

object[]

required

Show child attributes

weights

string | null

As on the update. Omitted keeps the current pin; null clears it.

resources

object

A full object. An omitted accelerators is [] (CPU); an omitted cpu or memory value is unset.

Show child attributes

extra_args

string[]

variables

object

The full map. An omitted name is removed.

Show child attributes

deployment_strategy

enum<string>

default:ROLLING

Available options:

ROLLING,

REPLACE_ALL

interrupt_sessions

boolean

default:false

Response

The environment after the write.

string<uuid>

required

The environment's ID. It is neither the project's nor the model's ID.

project_id

string<uuid>

required

name

string

required

image

object | null

required

The current image. For production, the deployed release's image. Null for another environment before its first revision.

Show child attributes

weights

object | null

required

The pinned weights. Null when none are pinned.

Show child attributes

resources

object

required

What each instance gets.

Show child attributes

extra_args

string[]

required

Extra arguments passed to the model container.

node_selector

string | null

required

Read-only.

instances

object[]

required

Show child attributes

revision

object | null

required

The current revision. Null before the first revision.

Show child attributes

public

boolean

required

When true, any authenticated caller can open sessions on production. It grants no read. Read-only for customers.

created_at

string<date-time>

required

deleted_at

string<date-time> | null

required

When the environment was deleted. A deleted environment takes no writes.

variables

object

Variables keyed by name. Names use letters, digits, _, -, and ., with no leading digit. Reserved names such as MODEL_NAME and any REACTOR_ name are refused.

Show child attributes

⌘I

Replace an environment

curl --request PUT \
  --url https://api.reactor.inc/projects/{proj_id}/environments/{env} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "image": {
    "tag": "v1.4.0"
  },
  "resources": {
    "accelerators": [
      {
        "type": "NVIDIA_H100",
        "count": 1
      }
    ]
  },
  "instances": [
    {
      "count": 2
    }
  ],
  "variables": {
    "LOG_LEVEL": {
      "value": "info"
    },
    "API_KEY": {
      "secret": "API_KEY"
    }
  }
}
'

import requests

url = "https://api.reactor.inc/projects/{proj_id}/environments/{env}"

payload = {
    "image": { "tag": "v1.4.0" },
    "resources": { "accelerators": [
            {
                "type": "NVIDIA_H100",
                "count": 1
            }
        ] },
    "instances": [{ "count": 2 }],
    "variables": {
        "LOG_LEVEL": { "value": "info" },
        "API_KEY": { "secret": "API_KEY" }
    }
}
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({
    image: {tag: 'v1.4.0'},
    resources: {accelerators: [{type: 'NVIDIA_H100', count: 1}]},
    instances: [{count: 2}],
    variables: {LOG_LEVEL: {value: 'info'}, API_KEY: {secret: 'API_KEY'}}
  })
};

fetch('https://api.reactor.inc/projects/{proj_id}/environments/{env}', 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/projects/{proj_id}/environments/{env}",
  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([
    'image' => [
        'tag' => 'v1.4.0'
    ],
    'resources' => [
        'accelerators' => [
                [
                                'type' => 'NVIDIA_H100',
                                'count' => 1
                ]
        ]
    ],
    'instances' => [
        [
                'count' => 2
        ]
    ],
    'variables' => [
        'LOG_LEVEL' => [
                'value' => 'info'
        ],
        'API_KEY' => [
                'secret' => 'API_KEY'
        ]
    ]
  ]),
  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.reactor.inc/projects/{proj_id}/environments/{env}"

	payload := strings.NewReader("{\n  \"image\": {\n    \"tag\": \"v1.4.0\"\n  },\n  \"resources\": {\n    \"accelerators\": [\n      {\n        \"type\": \"NVIDIA_H100\",\n        \"count\": 1\n      }\n    ]\n  },\n  \"instances\": [\n    {\n      \"count\": 2\n    }\n  ],\n  \"variables\": {\n    \"LOG_LEVEL\": {\n      \"value\": \"info\"\n    },\n    \"API_KEY\": {\n      \"secret\": \"API_KEY\"\n    }\n  }\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.reactor.inc/projects/{proj_id}/environments/{env}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"image\": {\n    \"tag\": \"v1.4.0\"\n  },\n  \"resources\": {\n    \"accelerators\": [\n      {\n        \"type\": \"NVIDIA_H100\",\n        \"count\": 1\n      }\n    ]\n  },\n  \"instances\": [\n    {\n      \"count\": 2\n    }\n  ],\n  \"variables\": {\n    \"LOG_LEVEL\": {\n      \"value\": \"info\"\n    },\n    \"API_KEY\": {\n      \"secret\": \"API_KEY\"\n    }\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.reactor.inc/projects/{proj_id}/environments/{env}")

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  \"image\": {\n    \"tag\": \"v1.4.0\"\n  },\n  \"resources\": {\n    \"accelerators\": [\n      {\n        \"type\": \"NVIDIA_H100\",\n        \"count\": 1\n      }\n    ]\n  },\n  \"instances\": [\n    {\n      \"count\": 2\n    }\n  ],\n  \"variables\": {\n    \"LOG_LEVEL\": {\n      \"value\": \"info\"\n    },\n    \"API_KEY\": {\n      \"secret\": \"API_KEY\"\n    }\n  }\n}"

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

{
  "id": "4b5c6d7e-8f90-4a1b-8c2d-3e4f5a6b7c8d",
  "project_id": "0d3c6f4e-8a1b-4c2d-9e7f-1a2b3c4d5e6f",
  "name": "production",
  "image": {
    "tag": "v1.4.0",
    "digest": "sha256:9e01aa47c3b2d5f6e7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0",
    "ref": null
  },
  "weights": null,
  "resources": {
    "accelerators": [
      {
        "type": "NVIDIA_H100",
        "count": 1
      }
    ]
  },
  "extra_args": [],
  "node_selector": null,
  "instances": [
    {
      "count": 2
    }
  ],
  "variables": {
    "LOG_LEVEL": {
      "value": "info"
    },
    "API_KEY": {
      "secret": "API_KEY",
      "version_id": "018cc820-e222-7ba6-9f43-7cf0b7e3a112"
    }
  },
  "revision": {
    "number": 5,
    "created_by": {
      "user_id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d"
    },
    "created_at": "2026-10-11T08:00:00Z"
  },
  "public": false,
  "created_at": "2026-10-09T08:53:20Z",
  "deleted_at": null
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>"
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>"
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>"
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>"
}

{
  "error": "failed_precondition",
  "reason": "environment_incomplete",
  "message": "environment staging is not complete: set image",
  "missing_fields": [
    "image"
  ]
}

{
  "error": "etag_mismatch",
  "message": "environment staging is at revision 4, not 3"
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>",
  "quota_type": "<string>",
  "limit": "<string>",
  "current": "<string>",
  "field": "<string>"
}

{
  "error": "<string>",
  "message": "<string>",
  "resource": "<string>",
  "reason": "<string>"
}

Get started

SDK Reference

CLI Reference

Platform API Reference

Endpoints

Replace an environment

Authorizations

Headers

Path Parameters

Body

Response