# Start a milestone (deprecated)

POST https://app.unleash-instance.example.com/api/admin/projects/{project}/features/{featureName}/environments/{environment}/release_plans/{planId}/milestones/{milestoneId}/start

**Enterprise feature**

Starts a release plan milestone for a specific feature flag and environment. Deprecated, please use /release-plans/:planId/milestones/:milestoneId/start instead.

Reference: https://docs.getunleash.io/api/old-start-milestone

## OpenAPI Specification

```yaml
openapi: 3.1.1
info:
  title: Start a release plan milestone.
  version: endpoint_releaseTemplates.oldStartMilestone
paths:
  /api/admin/projects/{project}/features/{featureName}/environments/{environment}/release_plans/{planId}/milestones/{milestoneId}/start:
    post:
      operationId: old-start-milestone
      summary: Start a release plan milestone.
      description: >-
        **Enterprise feature**


        Starts a release plan milestone for a specific feature flag and
        environment. Deprecated, please use
        /release-plans/:planId/milestones/:milestoneId/start instead.
      tags:
        - - subpackage_releaseTemplates
      parameters:
        - name: project
          in: path
          required: true
          schema:
            type: string
        - name: featureName
          in: path
          required: true
          schema:
            type: string
        - name: environment
          in: path
          required: true
          schema:
            type: string
        - name: planId
          in: path
          required: true
          schema:
            type: string
        - name: milestoneId
          in: path
          required: true
          schema:
            type: string
        - name: Authorization
          in: header
          description: Header authentication of the form `undefined <token>`
          required: true
          schema:
            type: string
      responses:
        '200':
          description: '#/components/schemas/releasePlanMilestoneSchema'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/releasePlanMilestoneSchema'
        '401':
          description: >-
            Authorization information is missing or invalid. Provide a valid API
            token as the `authorization` header, e.g.
            `authorization:*.*.my-admin-token`.
          content: {}
        '403':
          description: >-
            The provided user credentials are valid, but the user does not have
            the necessary permissions to perform this operation
          content: {}
        '404':
          description: The requested resource was not found.
          content: {}
components:
  schemas:
    ReleasePlanMilestoneSchemaTransitionCondition:
      type: object
      properties:
        intervalMinutes:
          type: integer
          description: The interval in minutes before transitioning
      required:
        - intervalMinutes
    parametersSchema:
      type: object
      additionalProperties:
        type: string
    ConstraintSchemaOperator:
      type: string
      enum:
        - value: NOT_IN
        - value: IN
        - value: STR_ENDS_WITH
        - value: STR_STARTS_WITH
        - value: STR_CONTAINS
        - value: NUM_EQ
        - value: NUM_GT
        - value: NUM_GTE
        - value: NUM_LT
        - value: NUM_LTE
        - value: DATE_AFTER
        - value: DATE_BEFORE
        - value: SEMVER_EQ
        - value: SEMVER_GT
        - value: SEMVER_LT
    constraintSchema:
      type: object
      properties:
        contextName:
          type: string
          description: The name of the context field that this constraint should apply to.
        operator:
          $ref: '#/components/schemas/ConstraintSchemaOperator'
          description: >-
            The operator to use when evaluating this constraint. For more
            information about the various operators, refer to [the strategy
            constraint operator
            documentation](https://docs.getunleash.io/concepts/activation-strategies#constraint-operators).
        caseInsensitive:
          type: boolean
          default: false
          description: >-
            Whether the operator should be case sensitive or not. Defaults to
            `false` (being case sensitive).
        inverted:
          type: boolean
          default: false
          description: >-
            Whether the result should be negated or not. If `true`, will turn a
            `true` result into a `false` result and vice versa.
        values:
          type: array
          items:
            type: string
          description: >-
            The context values that should be used for constraint evaluation.
            Use this property instead of `value` for properties that accept
            multiple values.
        value:
          type: string
          description: >-
            The context value that should be used for constraint evaluation. Use
            this property instead of `values` for properties that only accept
            single values.
      required:
        - contextName
        - operator
    CreateStrategyVariantSchemaWeightType:
      type: string
      enum:
        - value: variable
        - value: fix
    CreateStrategyVariantSchemaPayloadType:
      type: string
      enum:
        - value: json
        - value: csv
        - value: string
        - value: number
    CreateStrategyVariantSchemaPayload:
      type: object
      properties:
        type:
          $ref: '#/components/schemas/CreateStrategyVariantSchemaPayloadType'
          description: >-
            The type of the value. Commonly used types are string, number, json
            and csv.
        value:
          type: string
          description: The actual value of payload
      required:
        - type
        - value
    createStrategyVariantSchema:
      type: object
      properties:
        name:
          type: string
          description: The variant name. Must be unique for this feature flag
        weight:
          type: integer
          description: >-
            The weight is the likelihood of any one user getting this variant.
            It is an integer between 0 and 1000. See the section on [variant
            weights](https://docs.getunleash.io/concepts/feature-flag-variants#variant-weight)
            for more information
        weightType:
          $ref: '#/components/schemas/CreateStrategyVariantSchemaWeightType'
          description: >-
            Set to `fix` if this variant must have exactly the weight allocated
            to it. If the type is `variable`, the weight will adjust so that the
            total weight of all variants adds up to 1000. Refer to the [variant
            weight
            documentation](https://docs.getunleash.io/concepts/feature-flag-variants#variant-weight).
        stickiness:
          type: string
          description: >-
            The
            [stickiness](https://docs.getunleash.io/concepts/feature-flag-variants#variant-stickiness)
            to use for distribution of this variant. Stickiness is how Unleash
            guarantees that the same user gets the same variant every time
        payload:
          $ref: '#/components/schemas/CreateStrategyVariantSchemaPayload'
          description: Extra data configured for this variant
      required:
        - name
        - weight
        - weightType
        - stickiness
    releasePlanMilestoneStrategySchema:
      type: object
      properties:
        id:
          type: string
          description: The milestone strategy's ID. Milestone strategy IDs are ulids.
        milestoneId:
          type: string
          description: The ID of the milestone that this strategy belongs to.
        sortOrder:
          type: number
          format: double
          description: The order of the strategy in the list
        title:
          type:
            - string
            - 'null'
          description: A descriptive title for the strategy
        strategyName:
          type: string
          description: The name of the strategy type
        parameters:
          $ref: '#/components/schemas/parametersSchema'
          description: An object containing the parameters for the strategy
        constraints:
          type: array
          items:
            $ref: '#/components/schemas/constraintSchema'
          description: >-
            A list of the constraints attached to the strategy. See
            https://docs.getunleash.io/concepts/activation-strategies#constraints
        variants:
          type: array
          items:
            $ref: '#/components/schemas/createStrategyVariantSchema'
          description: Strategy level variants
        segments:
          type: array
          items:
            type: number
            format: double
          description: Ids of segments to use for this strategy
      required:
        - id
        - milestoneId
        - sortOrder
        - strategyName
    releasePlanMilestoneSchema:
      type: object
      properties:
        id:
          type: string
          description: The milestone's ID. Milestone IDs are ulids.
        name:
          type: string
          description: The name of the milestone.
        sortOrder:
          type: integer
          description: The order of the milestone in the release plan.
        releasePlanDefinitionId:
          type: string
          description: The ID of the release plan/template that this milestone belongs to.
        startedAt:
          type:
            - string
            - 'null'
          format: date-time
          description: The date and time when the milestone was started.
        transitionCondition:
          oneOf:
            - $ref: >-
                #/components/schemas/ReleasePlanMilestoneSchemaTransitionCondition
            - type: 'null'
          description: The condition configuration for the transition
        progressionExecutedAt:
          type:
            - string
            - 'null'
          format: date-time
          description: The date and time when the milestone progression was executed.
        pausedAt:
          type:
            - string
            - 'null'
          format: date-time
          description: The date and time when the milestone was paused.
        strategies:
          type: array
          items:
            $ref: '#/components/schemas/releasePlanMilestoneStrategySchema'
          description: A list of strategies that are attached to this milestone.
      required:
        - id
        - name
        - sortOrder
        - releasePlanDefinitionId

```

## SDK Code Examples

```python
import requests

url = "https://app.unleash-instance.example.com/api/admin/projects/project/features/featureName/environments/environment/release_plans/planId/milestones/milestoneId/start"

headers = {"Authorization": "<apiKey>"}

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

print(response.json())
```

```javascript
const url = 'https://app.unleash-instance.example.com/api/admin/projects/project/features/featureName/environments/environment/release_plans/planId/milestones/milestoneId/start';
const options = {method: 'POST', headers: {Authorization: '<apiKey>'}};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

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

func main() {

	url := "https://app.unleash-instance.example.com/api/admin/projects/project/features/featureName/environments/environment/release_plans/planId/milestones/milestoneId/start"

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

	req.Header.Add("Authorization", "<apiKey>")

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

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

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://app.unleash-instance.example.com/api/admin/projects/project/features/featureName/environments/environment/release_plans/planId/milestones/milestoneId/start")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<apiKey>'

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

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://app.unleash-instance.example.com/api/admin/projects/project/features/featureName/environments/environment/release_plans/planId/milestones/milestoneId/start")
  .header("Authorization", "<apiKey>")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://app.unleash-instance.example.com/api/admin/projects/project/features/featureName/environments/environment/release_plans/planId/milestones/milestoneId/start', [
  'headers' => [
    'Authorization' => '<apiKey>',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://app.unleash-instance.example.com/api/admin/projects/project/features/featureName/environments/environment/release_plans/planId/milestones/milestoneId/start");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "<apiKey>");
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["Authorization": "<apiKey>"]

let request = NSMutableURLRequest(url: NSURL(string: "https://app.unleash-instance.example.com/api/admin/projects/project/features/featureName/environments/environment/release_plans/planId/milestones/milestoneId/start")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```