---
title: Change the HTTP Host header and DNS record
description: Create an origin rule to change the HTTP `Host` header and the resolved DNS record.
image: https://edgetunnel-b2h.pages.dev/core-services-preview.png
---

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# Change the HTTP Host header and DNS record

Create an origin rule to change the HTTP `Host` header and DNS record.

The following origin rule overrides the HTTP `Host` header to `hr-server.example.com` for all requests with a URI path starting with `/hr-app/`. It also overrides the DNS record to the same hostname.

The `Host` header override only updates the header value; the DNS record override will handle the rerouting of incoming requests. For more information on these overrides, refer to [Origin Rules settings](https://edgetunnel-b2h.pages.dev/rules/origin-rules/features/).

* [ Dashboard ](#tab-panel-10853)
* [ API ](#tab-panel-10854)

Expression when using the Expression Builder:

| Field    | Operator    | Value    |
| -------- | ----------- | -------- |
| URI Path | starts with | /hr-app/ |

Expression when using the Expression Editor:

```txt
(starts_with(http.request.uri.path, "/hr-app/"))
```

Value after **Host Header** \> **Rewrite to**:

```txt
hr-server.example.com
```

Value after **DNS Record** \> **Override to**:

```txt
hr-server.example.com
```

The following example sets the rules of an existing phase ruleset (`$RULESET_ID`) to a single origin rule — overriding the `Host` header of incoming requests and the resolved DNS record — using the [Update a zone ruleset](https://edgetunnel-b2h.pages.dev/api/resources/rulesets/methods/update/) operation. The response will contain the complete definition of the ruleset you updated.

Required API token permissions

At least one of the following [token permissions](https://edgetunnel-b2h.pages.dev/fundamentals/api/reference/permissions/) is required: 
* `Response Compression Write`
* `Config Settings Write`
* `Dynamic URL Redirects Write`
* `Cache Settings Write`
* `Custom Errors Write`
* `Origin Write`
* `Managed headers Write`
* `Zone Transform Rules Write`
* `Mass URL Redirects Write`
* `Magic Firewall Write`
* `L4 DDoS Managed Ruleset Write`
* `HTTP DDoS Managed Ruleset Write`
* `Sanitize Write`
* `Transform Rules Write`
* `Select Configuration Write`
* `Bot Management Write`
* `Zone WAF Write`
* `Account WAF Write`
* `Account Rulesets Write`
* `Logs Write`
* `Logs Write`

**Update a zone ruleset**

```bash
curl "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/rulesets/$RULESET_ID" \
  --request PUT \
  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
  --json '{
    "rules": [
        {
            "ref": "hr_app_overrides",
            "expression": "starts_with(http.request.uri.path, \"/hr-app/\")",
            "description": "Origin rule for the company HR application",
            "action": "route",
            "action_parameters": {
                "host_header": "hr-server.example.com",
                "origin": {
                    "host": "hr-server.example.com"
                }
            }
        }
    ]
  }'
```

```json
{
  "result": {
    "id": "<RULESET_ID>",
    "name": "Origin Rules ruleset",
    "description": "Zone-level ruleset that will execute origin rules.",
    "kind": "zone",
    "version": "2",
    "rules": [
      {
        "ref": "hr_app_overrides",
        "id": "<RULE_ID>",
        "version": "1",
        "action": "route",
        "action_parameters": {
          "host_header": "hr-server.example.com",
          "origin": {
            "host": "hr-server.example.com"
          }
        },
        "expression": "starts_with(http.request.uri.path, \"/hr-app/\")",
        "description": "Origin rule for the company HR application",
        "last_updated": "2022-06-03T14:42:04.219025Z",
        "ref": "<RULE_REF>"
      }
    ],
    "last_updated": "2022-06-03T14:42:04.219025Z",
    "phase": "http_request_origin"
  },
  "success": true,
  "errors": [],
  "messages": []
}
```

Use the `ref` field to get stable rule IDs across updates when using Terraform. Adding this field prevents Terraform from recreating the rule on changes. For more information, refer to [Troubleshooting](https://edgetunnel-b2h.pages.dev/terraform/troubleshooting/rule-id-changes/#how-to-keep-the-same-rule-id-between-modifications) in the Terraform documentation.

```json
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{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/rules/","name":"Rules"}},{"@type":"ListItem","position":3,"item":{"@id":"/rules/origin-rules/","name":"Origin Rules"}},{"@type":"ListItem","position":4,"item":{"@id":"/rules/origin-rules/examples/","name":"Origin Rules examples"}},{"@type":"ListItem","position":5,"item":{"@id":"/rules/origin-rules/examples/change-http-host-header/","name":"Change the HTTP Host header and DNS record"}}]}
```