# Hostname Associations

## List Hostname Associations

`client.CertificateAuthorities.HostnameAssociations.Get(ctx, params) (*HostnameAssociationGetResponse, error)`

**get** `/zones/{zone_id}/certificate_authorities/hostname_associations`

List Hostname Associations

### Parameters

- `params HostnameAssociationGetParams`

  - `ZoneID param.Field[string]`

    Path param: Identifier.

  - `MTLSCertificateID param.Field[string]`

    Query param: The UUID to match against for a certificate that was uploaded to the mTLS Certificate Management endpoint. If no mtls_certificate_id is given, the results will be the hostnames associated to your active Cloudflare Managed CA.

### Returns

- `type HostnameAssociationGetResponse struct{…}`

  - `Hostnames []HostnameAssociation`

### Example

```go
package main

import (
  "context"
  "fmt"

  "github.com/cloudflare/cloudflare-go"
  "github.com/cloudflare/cloudflare-go/certificate_authorities"
  "github.com/cloudflare/cloudflare-go/option"
)

func main() {
  client := cloudflare.NewClient(
    option.WithAPIToken("Sn3lZJTBX6kkg7OdcBUAxOO963GEIyGQqnFTOFYY"),
  )
  hostnameAssociation, err := client.CertificateAuthorities.HostnameAssociations.Get(context.TODO(), certificate_authorities.HostnameAssociationGetParams{
    ZoneID: cloudflare.F("023e105f4ecef8ad9ca31a8372d0c353"),
  })
  if err != nil {
    panic(err.Error())
  }
  fmt.Printf("%+v\n", hostnameAssociation.Hostnames)
}
```

#### Response

```json
{
  "errors": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "messages": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "success": true,
  "result": {
    "hostnames": [
      "api.example.com"
    ]
  }
}
```

## Replace Hostname Associations

`client.CertificateAuthorities.HostnameAssociations.Update(ctx, params) (*HostnameAssociationUpdateResponse, error)`

**put** `/zones/{zone_id}/certificate_authorities/hostname_associations`

Replace Hostname Associations

### Parameters

- `params HostnameAssociationUpdateParams`

  - `ZoneID param.Field[string]`

    Path param: Identifier.

  - `TLSHostnameAssociation param.Field[TLSHostnameAssociation]`

    Body param

### Returns

- `type HostnameAssociationUpdateResponse struct{…}`

  - `Hostnames []HostnameAssociation`

### Example

```go
package main

import (
  "context"
  "fmt"

  "github.com/cloudflare/cloudflare-go"
  "github.com/cloudflare/cloudflare-go/certificate_authorities"
  "github.com/cloudflare/cloudflare-go/option"
)

func main() {
  client := cloudflare.NewClient(
    option.WithAPIToken("Sn3lZJTBX6kkg7OdcBUAxOO963GEIyGQqnFTOFYY"),
  )
  hostnameAssociation, err := client.CertificateAuthorities.HostnameAssociations.Update(context.TODO(), certificate_authorities.HostnameAssociationUpdateParams{
    ZoneID: cloudflare.F("023e105f4ecef8ad9ca31a8372d0c353"),
    TLSHostnameAssociation: certificate_authorities.TLSHostnameAssociationParam{

    },
  })
  if err != nil {
    panic(err.Error())
  }
  fmt.Printf("%+v\n", hostnameAssociation.Hostnames)
}
```

#### Response

```json
{
  "errors": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "messages": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "success": true,
  "result": {
    "hostnames": [
      "api.example.com"
    ]
  }
}
```

## Domain Types

### Hostname Association

- `type HostnameAssociation string`

### TLS Hostname Association

- `type TLSHostnameAssociation struct{…}`

  - `Hostnames []HostnameAssociation`

  - `MTLSCertificateID string`

    The UUID for a certificate that was uploaded to the mTLS Certificate Management endpoint. If no mtls_certificate_id is given, the hostnames will be associated to your active Cloudflare Managed CA.