# API

## Feature Toggles

### Fetching Feature Toggles

**GET: http://unleash.host.com/api/features**

**HEADERS:**

* UNLEASH-APPNAME: appName
* UNLEASH-INSTANCEID: instanceId

This endpoint is the one all clients should use to fetch all available feature toggles 
from the _unleash-server_. The response returns all active feature toggles and their 
current strategy configuration. A feature toggle will have _at least_ one configured strategy. 
A strategy will have a `name` and `parameters` map.

> _Note:_ Clients should perfer the `strategies` property. 
> Legacy properties (`strategy` & `parameters`) will be kept until **version 2** of the format.   

This endpoint should never return anything besides a valid *20X or 304-response*. It will also 
include a `Etag`-header. The value of this header can be used by clients as the value of 
the `If-None-Match`-header in the request to prevent a data transfer if the clients already
has the latest response locally.

**Example response:**
```json
{
  "version": 1,
  "features": [
    {
      "name": "Feature.A",
      "description": "lorem ipsum",
      "enabled": false,
      "strategies": [
        {
          "name": "default",
          "parameters": {}
        }
      ],
      "strategy": "default",
      "parameters": {}
    },
    {
      "name": "Feature.B",
      "description": "lorem ipsum",
      "enabled": true,
      "strategies": [
        {
          "name": "ActiveForUserWithId",
          "parameters": {
            "userIdList": "123,221,998"
          }
        },
        {
          "name": "GradualRolloutRandom",
          "parameters": {
            "percentage": "10"
          }
        }
      ],
      "strategy": "ActiveForUserWithId",
      "parameters": {
        "userIdList": "123,221,998"
      }
    }
  ]
}
```

**GET: http://unleash.host.com/api/features/:featureName**

Used to fetch details about a specific featureToggle. This is mostly provded to make it easy to 
debug the API and should not be used by the client implementations.

> _Notice_: You will not get a version property when fetching a specific feature toggle by name.  

```json
{
  "name": "Feature.A",
  "description": "lorem ipsum..",
  "enabled": false,
  "strategies": [
    {
      "name": "default",
      "parameters": {}
    }
  ],
  "strategy": "default",
  "parameters": {}
}
```


### Create a new Feature Toggle

**POST: http://unleash.host.com/api/features/**

**Body:**
 ```json
{
  "name": "Feature.A",
  "description": "lorem ipsum..",
  "enabled": false,
  "strategies": [
    {
      "name": "default",
      "parameters": {}
    }
  ]
}
```

Used by the admin-dashboard to create a new feature toggles. The name **must be unique**, 
otherwise you will get a _403-response_.  

Returns 200-respose if the feature toggle was created successfully. 

### Update a Feature Toggle

**PUT: http://unleash.host.com/api/features/:toggleName**

**Body:**
 ```json
{
  "name": "Feature.A",
  "description": "lorem ipsum..",
  "enabled": false,
  "strategies": [
    {
      "name": "default",
      "parameters": {}
    }
  ]
}
```

Used by the admin dashboard to update a feature toggles. The name has to match an 
existing features toggle. 

Returns 200-respose if the feature toggle was updated successfully. 

### Archive a Feature Toggle

**DELETE: http://unleash.host.com/api/features/:toggleName**

Used to archive a feature toggle. A feature toggle can never be totally be deleted, 
but can be archived. This is a design decision to make sure that a old feature 
toggle suddnely reapear by some one else reusing the same name.

## Archive

### Fetch archived toggles

**GET http://unleash.host.com/api/archive/features**

Used to fetch list of archived feature toggles

**Example response:**
```json
{
  "version": 1,
  "features": [
    {
      "name": "Feature.A",
      "description": "lorem ipsum",
      "enabled": false,
      "strategies": [
        {
          "name": "default",
          "parameters": {}
        }
      ],
      "strategy": "default",
      "parameters": {}
    }
  ]
}
```

### Revive feature toggle

**POST http://unleash.host.com/api/archive/revive**

**Body:**
 ```json
{
  "name": "Feature.A"
}
```

Used to revive a feature toggle. 


## Strategies

### Fetch Strategies 
**GET: http://unleash.host.com/api/strategies**

Used to fetch all defined strategies and their defined paramters. 

**Response**

 ```json
{
    "version": 1,
    "strategies": [
        {
        "name": "default",
        "description": "Default on/off strategy.",
            "parametersTemplate": null
        },
        {
            "name": "ActiveForUserWithEmail",
            "description": "A comma separated list of email adresses this feature should be active for.",
            "parametersTemplate": {
                "emails": "string"
            }
        },
        {
            "name": "Accounts",
            "description": "Enable for user accounts",
            "parametersTemplate": {
                "Accountname": "string"
            }
        }
]}
```

### Create strategy

**POST: http://unleash.host.com/api/strategies**

**Body**

```json
{
    "name": "ActiveForUserWithEmail",
    "description": "A comma separated list of email adresses this feature should be active for.",
    "parametersTemplate": {
        "emails": "string"
    }
}
```

Used to create a new Strategy. Name must be unique. 



# Events

**GET: http://unleash.host.com/api/events**

Used to fetch all changes in the unleash system.

Event types:

- feature-created
- feature-updated
- feature-archived
- feature-revived
- strategy-created
- strategy-deleted

**Response**

 ```json
{
    "version": 1,
    "events":[
        {
            "id":454,
            "type":"feature-updated",
            "createdBy":"unknown",
            "createdAt":"2016-08-24T11:22:01.354Z",
            "data": {
                "name":"eid.bankid.mobile",
                "description":"",
                "strategy":"default",
                "enabled":true,
                "parameters":{}
            },
            "diffs": [
                {"kind":"E","path":["enabled"],"lhs":false,"rhs":true}
            ]
        }
    ]
}
```


# Metrics

**GET: http://unleash.host.com/api/metrics**

Get aggregated state of metrics 

```json
{
    "globalCount": 1420,
    "apps": {
        "app-name": {
            "count": 1420,
            "clients": [
                "instance-id"
            ]
        }
    },
    "clients": {
        "instance-id": {
            "appName": "app-name",
            "count": 1420,
            "started": "2016-11-13T19:50:54.395Z",
            "init": "2016-11-13T19:50:54.395Z",
            "ping": "2016-11-13T19:51:14.403Z"
        }
    }
}
```


**GET: http://unleash.host.com/api/metrics/features**

Get metrics per toggle 

```json
{
    "lastHour": {
        "toggle-name-1": {
            "yes": 0,
            "no": 720
        },
        "toggle-name-2": {
            "yes": 0,
            "no": 463
        },
        "toggle-name-3": {
            "yes": 237,
            "no": 0
        }
    },
    "lastMinute": {
        "toggle-name-1": {
            "yes": 0,
            "no": 0
        },
        "toggle-name-2": {
            "yes": 0,
            "no": 0
        },
        "toggle-name-3": {
            "yes": 0,
            "no": 0
        }
    }
}
```

**POST: http://unleash.host.com/api/client/register**

Register a client instance with the unleash server

```json
{
    "appName": "appName",
    "instanceId": "instanceId",
    "strategies": ["default", "some-strategy-1"],
    "started": "2016-11-03T07:16:43.572Z",
    "interval": 10000,
}
```

**POST: http://unleash.host.com/api/client/metrics**

Register a metrics payload with a timed bucket

```json
{
    "appName": "appName",
    "instanceId": "instanceId",
    "bucket": {
        "start": "2016-11-03T07:16:43.572Z",
        "stop": "2016-11-03T07:16:53.572Z",
        "toggles": {
            "toggle-name-1": {
                "yes": 123,
                "no": 321
            }
        }
    },
}
```