# Header Tagger

**Zoraxy plugin** — Copy custom headers from a source domain to every other domain sharing the same tag.

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## The Problem

Zoraxy forwards `X-Forwarded-For`, `X-Real-IP`, `X-Forwarded-Proto`, and `X-Forwarded-Host` natively, but when you want a *custom* header on many domains (e.g. `X-Original-Client-IP = $remote_addr`, or a security header), you'd normally set it manually on every domain — one by one.

## The Solution

Define the header **once** on a source domain, tag it, then let this plugin copy it to all other domains sharing the tag.

```
Tag "tracking":
├── app.example.com   ← manually set X-Original-Client-IP = $remote_addr (SOURCE)
├── api.example.com   ← plugin copies the header here
└── cdn.example.com   ← and here
```

---

## Usage

1. In Zoraxy, edit a domain → **Advanced Settings → Custom Headers** → add your headers.
2. Tag that domain (e.g. `tracking`).
3. Tag the other domains with the same tag.
4. Open the plugin at `/plugin.ui/zoraxy-headers/`.
5. Click **Apply to selected** — the plugin copies the source's headers to the selected targets.

Use **Remove from selected** to strip those headers from targets.

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## Supported Dynamic Header Values

Zoraxy v3.1.2+ supports nginx-style `$variable` placeholders in request-direction header values:

| Placeholder | Meaning |
|-------------|---------|
| `$remote_addr` | Client IP |
| `$host` | Original host |
| `$scheme` | http / https |
| `$request_uri` | Full request URI |
| `$request_method` | GET / POST / ... |
| `$http_user_agent` | User-Agent |
| `$http_referer` | Referer |

Example — preserve the original client IP in a custom header:

```
Header: X-Original-Client-IP = $remote_addr   (request direction)
```

---

## Install

```bash
curl -sSL https://git.lohmar.co.uk/cclohmar/zoraxy-headers/raw/branch/main/install.sh | sudo bash
```

Or manually:

```bash
git clone https://git.lohmar.co.uk/cclohmar/zoraxy-headers.git /opt/zoraxy/plugins/zoraxy-headers
cd /opt/zoraxy/plugins/zoraxy-headers
go build -buildvcs=false -o zoraxy-headers .
systemctl restart zoraxy
```

Then enable **Header Tagger** in Zoraxy → Plugins.

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## How It Works

The plugin uses Zoraxy's plugin API key (scoped to proxy list + header endpoints) to:

1. `GET /api/proxy/list?type=host` → all domains and their tags
2. Group domains by tag, identify the "source" (a domain that already has headers)
3. `POST /api/proxy/header/add` / `remove` → copy the source's headers to targets

No root access needed — the API key is scoped to only the required endpoints.

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## API Endpoints (plugin UI)

| Method | Path | Purpose |
|--------|------|---------|
| `GET` | `/ui/api/groups` | List tags → domains → source |
| `POST` | `/ui/api/apply` | Copy source headers to targets |
| `POST` | `/ui/api/remove` | Remove headers from targets |

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## Requirements

- Zoraxy v3.2.0+
- Go 1.21+ (to build)

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## License

Zoraxy plugin SDK is LGPL. This plugin is open source.