# Render Variables API

Contents

* [Render Variables API](/api-guides/render-variables-api.md)
  * [Creating a variable](#creating-a-variable)
  * [Updating a variable](#updating-a-variable)
  * [Search variables](#search-variables)
  * [Get variable values](#get-variable-values)
  * [Delete a variable](#delete-a-variable)
  * [Graphing with render variables](#graphing-with-render-variables)

Render Variables provide versatility when constructing metric queries. Instead of hard-coding full metric names, use variables as placeholders to dynamically build your queries. This is similar, but not the same as the primary dashboard’s built-in template variables.

**NOTE**: we advise against using render variables in alert queries.

### [Creating a variable](#creating-a-variable)

<mark style="color:green;">`POST`</mark> `/v1/variables/<var-name>/`

Replace \<var-name> with the name you want to give the variable. Place your variable values in a JSON file and include it in the POST request. A variable name is required, however the values can be empty.

{% tabs %}
{% tab title="201" %}
Created { "url": "/v1/variables//" }
{% endtab %}

{% tab title="400" %}
Bad Request JSON could be incorrectly formatted or the variable name already exists
{% endtab %}
{% endtabs %}

**Example variable values:**

```json
{
  "values": [
    "foobar",
    "foo",
    "bar",
    "baz"
  ]
}
```

**Curl example:**

```bash
curl -X POST "https://YOUR-API-KEY@api.hostedgraphite.com/v1/variables/<var-name>/" -d @values.json
```

Make sure to include the forward slash character at the end of the request.

***

### [Updating a variable](#updating-a-variable)

<mark style="color:orange;">`PUT`</mark> `/v1/variables/<var-name>/`

Overwrites the values for an existing variable

{% tabs %}
{% tab title="200: OK {  "url": "/v1/variables/<var-name>/" }" %}

{% endtab %}

{% tab title="400: Bad Request JSON could be incorrectly formatted" %}

{% endtab %}

{% tab title="404: Not Found " %}

{% endtab %}
{% endtabs %}

**Curl example:**

```bash
curl -X PUT "https://<apikey>@api.hostedgraphite.com/v1/variables/<var-name>/" -d @values.json
```

***

### [Search variables](#search-variables)

<mark style="color:blue;">`GET`</mark> `/v1/variables/?query=`

A “contains” query that will return a JSON object with the name and path of variables that contain the search term. To list all variables, leave the query empty.

#### Path Parameters

| Name  | Type   | Description |
| ----- | ------ | ----------- |
| query | String |             |

{% tabs %}
{% tab title="200: OK {   "variables" : \[     {       "name" : "foo",       "url" : "/v1/variables/foo/"     },     {       "name" : "bar",       "url" : "/v1/variables/bar/"     }   ] }" %}

{% endtab %}
{% endtabs %}

**Curl example:**

```bash
curl -X GET "https://<apikey>@api.hostedgraphite.com/v1/variables/?query="
```

If you have no variables or there are no variables that match your query you will be returned with an empty object:

```json
{
  "variables": []
}
```

***

### [Get variable values](#get-variable-values)

<mark style="color:blue;">`GET`</mark> `/v1/variables/<var-name>/`

Returns a JSON object with the values assigned to \<var-name>

{% tabs %}
{% tab title="200: OK {   "values": \[     "foobar",     "foo",     "bar",     "baz"   ] }" %}

{% endtab %}

{% tab title="404: Not Found " %}

{% endtab %}
{% endtabs %}

**Curl example:**

```bash
curl -X GET "https://<apikey>@api.hostedgraphite.com/v1/variables/<var-name>/"
```

***

### [Delete a variable](#delete-a-variable)

<mark style="color:red;">`DELETE`</mark> `/v1/variables/<var-name>/`

{% tabs %}
{% tab title="200: OK " %}

{% endtab %}

{% tab title="404: Not Found " %}

{% endtab %}
{% endtabs %}

**Curl example:**

```bash
curl -X DELETE "https://<apikey>@api.hostedgraphite.com/v1/variables/<var-name>/"
```

***

### [Graphing with render variables](#graphing-with-render-variables)

This cannot be done with the simple query builder, you must toggle the edit mode to the free-text mode.

Refer to a render variable by including the variable name enclosed in angled brackets in your metric query: **\<variable-name>**

**Using dashboard templates within render variables**

You can place template variables within render variables by surrounding them with curly brackets:

```bash
$foo.<{$foo}_metric>.bar
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.hostedgraphite.com/api-guides/render-variables-api.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.