docs/en/latest/plugins/cors.md

---
title: cors
keywords:
  - Apache APISIX
  - API Gateway
  - CORS
description: This document contains information about the Apache APISIX cors Plugin.
---

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## Description

The `cors` Plugins lets you enable [CORS](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS) easily.

## Attributes

### CORS attributes

| Name                      | Type    | Required | Default | Description                                                                                                                                                                                                                                                                                                                                                                                        |
|---------------------------|---------|----------|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| allow_origins             | string  | False    | "*"     | Origins to allow CORS. Use the `scheme://host:port` format. For example, `https://somedomain.com:8081`. If you have multiple origins, use a `,` to list them. If `allow_credential` is set to `false`, you can enable CORS for all origins by using `*`. If `allow_credential` is set to `true`, you can forcefully allow CORS on all origins by using `**` but it will pose some security issues. |
| allow_methods             | string  | False    | "*"     | Request methods to enable CORS on. For example `GET`, `POST`. Use `,` to add multiple methods. If `allow_credential` is set to `false`, you can enable CORS for all methods by using `*`. If `allow_credential` is set to `true`, you can forcefully allow CORS on all methods by using `**` but it will pose some security issues.                                                                |
| allow_headers             | string  | False    | "*"     | Headers in the request allowed when accessing a cross-origin resource. Use `,` to add multiple headers. If `allow_credential` is set to `false`, you can enable CORS for all request headers by using `*`. If `allow_credential` is set to `true`, you can forcefully allow CORS on all request headers by using `**` but it will pose some security issues.                                       |
| expose_headers            | string  | False    |         | Headers in the response allowed when accessing a cross-origin resource. Use `,` to add multiple headers. If `allow_credential` is set to `false`, you can enable CORS for all response headers by using `*`. If not specified, the plugin will not modify the `Access-Control-Expose-Headers header`. See [Access-Control-Expose-Headers - MDN](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Expose-Headers) for more details.  |
| max_age                   | integer | False    | 5       | Maximum time in seconds the result is cached. If the time is within this limit, the browser will check the cached result. Set to `-1` to disable caching. Note that the maximum value is browser dependent. See [Access-Control-Max-Age](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Max-Age#Directives) for more details.                                            |
| allow_credential          | boolean | False    | false   | When set to `true`, allows requests to include credentials like cookies. According to CORS specification, if you set this to `true`, you cannot use '*' to allow all for the other attributes.                                                                                                                                                                                                     |
| allow_origins_by_regex    | array   | False    | nil     | Regex to match origins that allow CORS. For example, `[".*\.test.com$"]` can match all subdomains of `test.com`. When set to specified range, only domains in this range will be allowed, no matter what `allow_origins` is.                                                                                                                                                                   |
| allow_origins_by_metadata | array   | False    | nil     | Origins to enable CORS referenced from `allow_origins` set in the Plugin metadata. For example, if `"allow_origins": {"EXAMPLE": "https://example.com"}` is set in the Plugin metadata, then `["EXAMPLE"]` can be used to allow CORS on the origin `https://example.com`.                                                                                                                          |

:::info IMPORTANT

1. The `allow_credential` attribute is sensitive and must be used carefully. If set to `true` the default value `*` of the other attributes will be invalid and they should be specified explicitly.
2. When using `**` you are vulnerable to security risks like CSRF. Make sure that this meets your security levels before using it.

:::

### Resource Timing attributes

| Name                      | Type    | Required | Default | Description                                                                                                                                                                                                                                                                                                                                                                                        |
|---------------------------|---------|----------|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| timing_allow_origins             | string  | False    | nil     | Origin to allow to access the resource timing information. See [Timing-Allow-Origin](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Timing-Allow-Origin). Use the `scheme://host:port` format. For example, `https://somedomain.com:8081`. If you have multiple origins, use a `,` to list them. |
| timing_allow_origins_by_regex    | array   | False    | nil     | Regex to match with origin for enabling access to the resource timing information. For example, `[".*\.test.com"]` can match all subdomain of `test.com`. When set to specified range, only domains in this range will be allowed, no matter what `timing_allow_origins` is. |

:::note

The Timing-Allow-Origin header is defined in the Resource Timing API, but it is related to the CORS concept.

Suppose you have 2 domains, `domain-A.com` and `domain-B.com`.
You are on a page on `domain-A.com`, you have an XHR call to a resource on `domain-B.com` and you need its timing information.
You can allow the browser to show this timing information only if you have cross-origin permissions on `domain-B.com`.
So, you have to set the CORS headers first, then access the `domain-B.com` URL, and if you set [Timing-Allow-Origin](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Timing-Allow-Origin), the browser will show the requested timing information.

:::

## Metadata

| Name          | Type   | Required | Description                                                                                                                                                                                             |
|---------------|--------|----------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| allow_origins | object | False    | A map with origin reference and allowed origins. The keys in the map are used in the attribute `allow_origins_by_metadata` and the value are equivalent to the `allow_origins` attribute of the Plugin. |

## Enable Plugin

You can enable the Plugin on a specific Route or Service:

:::note
You can fetch the `admin_key` from `config.yaml` and save to an environment variable with the following command:

```bash
admin_key=$(yq '.deployment.admin.admin_key[0].key' conf/config.yaml | sed 's/"//g')
```

:::

```shell
curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -d '
{
    "uri": "/hello",
    "plugins": {
        "cors": {}
    },
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "127.0.0.1:8080": 1
        }
    }
}'
```

## Example usage

After enabling the Plugin, you can make a request to the server and see the CORS headers returned:

```shell
curl http://127.0.0.1:9080/hello -v
```

```shell
...
< Server: APISIX web server
< Access-Control-Allow-Origin: *
< Access-Control-Allow-Methods: *
< Access-Control-Allow-Headers: *
< Access-Control-Max-Age: 5
...
```

## Delete Plugin

To remove the `cors` Plugin, you can delete the corresponding JSON configuration from the Plugin configuration. APISIX will automatically reload and you do not have to restart for this to take effect.

```shell
curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -d '
{
    "uri": "/hello",
    "plugins": {},
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "127.0.0.1:8080": 1
        }
    }
}'
```