3x-ui/docs/content/docs/en/config/reality.mdx

---
title: REALITY
description: Set up a VLESS + REALITY inbound with XTLS-Vision in 3x-ui — keys, short IDs, SNI, fingerprints, and common pitfalls.
icon: ShieldCheck
---

**REALITY** is an Xray transport security that disguises your proxy as ordinary
traffic to a real, popular website. Unlike classic TLS, your server needs **no
certificate of its own** — it borrows the TLS handshake of the target site
(`dest`). Combined with the **XTLS-Vision** flow, it is fast and resistant to
deep-packet inspection.

REALITY is used with **VLESS** (and Trojan). The recommended flow is
`xtls-rprx-vision`.

## Key settings

When you choose **REALITY** as the security mode on a VLESS inbound, 3x-ui
exposes these fields:

| Field                    | What it is                                                         |
| ------------------------ | ------------------------------------------------------------------ |
| **Dest (target)**        | A real TLS site to impersonate, e.g. `www.microsoft.com:443`.      |
| **SNI / Server Names**   | The hostname(s) clients send; must match the target's certificate. |
| **Public / Private key** | An **x25519** keypair. The private key stays on the server.        |
| **Short IDs**            | Hex strings used to authenticate clients (you can have several).   |
| **Flow**                 | Set to `xtls-rprx-vision`.                                         |
| **Fingerprint (uTLS)**   | The client TLS fingerprint to mimic, e.g. `chrome`.                |

The private key is generated with Xray's `x25519` utility (the panel can
generate the pair for you):

```bash title="generate an x25519 keypair"
xray x25519
```

## Set it up in the panel

<Steps>

<Step>
### Create a VLESS inbound

Add a new inbound, choose protocol **VLESS**, and set **Security** to
**reality**.
</Step>

<Step>
### Choose a target (dest) and SNI

Pick a reputable site that supports TLS 1.3 and HTTP/2 and is reachable from your
server and your clients (for example `www.microsoft.com:443`). Set the server
names / SNI to match that site's certificate.
</Step>

<Step>
### Generate keys and short IDs

Generate the x25519 keypair and one or more short IDs. Keep the **private key**
secret; clients only ever receive the **public key**.
</Step>

<Step>
### Set the flow and fingerprint

Use the `xtls-rprx-vision` flow and a common uTLS fingerprint such as `chrome`.
</Step>

<Step>
### Add a client and share the link

Create a client, then use its share link or QR code in a compatible app
(v2rayNG, Hiddify, Mihomo, and others).
</Step>

</Steps>

## What the configuration looks like

On the server, a REALITY inbound's `streamSettings` looks roughly like this:

```json title="server inbound (excerpt)"
{
  "network": "tcp",
  "security": "reality",
  "realitySettings": {
    "dest": "www.microsoft.com:443",
    "serverNames": ["www.microsoft.com"],
    "privateKey": "<x25519 private key>",
    "shortIds": ["<hex short id>"],
    "fingerprint": "chrome"
  }
}
```

The matching client share link carries the **public** parameters:

```text title="vless:// (excerpt)"
vless://<uuid>@<server>:443?security=reality&pbk=<public-key>&sid=<short-id>&sni=www.microsoft.com&fp=chrome&spx=%2F&flow=xtls-rprx-vision#my-reality
```

- `pbk` — REALITY **public** key
- `sid` — short ID (matches one on the server)
- `sni` — server name (matches the target's certificate)
- `fp` — client fingerprint
- `spx` — spiderX path
- `flow` — `xtls-rprx-vision`

## Common pitfalls

<Callout type="warn">

- **Bad target.** The `dest` must be a real site that supports **TLS 1.3** and
  **HTTP/2**, is reachable, and isn't blocked in your region. Pick a site you do
  not own and that sees lots of traffic.
- **SNI mismatch.** The SNI / server names must match the target's real
  certificate, or the handshake gives the disguise away.
- **Leaked private key.** Only ever distribute the **public** key to clients.
- **Wrong flow.** REALITY + XTLS-Vision needs `flow = xtls-rprx-vision` on both
  the inbound client entry and the share link.
- **Client version limits.** Xray-core v26.9.8+ no longer sets a minimum when
  **Min Client Ver** is empty. An explicitly saved minimum still applies. Earlier
  builds may use a built-in minimum (such as `26.3.27`), rejecting third-party
  clients even with correct keys. Check the running core version before changing
  this gate; lowering it also admits older fingerprints.
- **Mihomo and ML-KEM.** Xray-core v26.9.8+ independently requires an
  `X25519MLKEM768` key share before the optional `X25519` share. The Clash/Mihomo
  YAML subscription enables `reality-opts.support-x25519mlkem768` for REALITY
  nodes, including external links, and uses `chrome` when no fingerprint was set.
  Explicit fingerprints are preserved: choose one that offers ML-KEM (`chrome`
  with Mihomo's uTLS v1.8.7); enabling the flag cannot upgrade an old fingerprint.
  Raw `vless://` links carry the equivalent `support-x25519mlkem768=true` hint;
  clients that support this URI extension, including current Mihomo builds, apply
  it on import. Servers on Xray-core older than 26.9.8 accept a plain `X25519`
  hello, and very old ones reject ML-KEM outright. For those, or where a network
  drops the larger ML-KEM ClientHello, enable **Mihomo X25519** on a Host: its
  Clash proxy gets `support-x25519mlkem768: false` and its `vless://` link drops
  the hint. Clearing the version limit alone does not fix the handshake.

</Callout>

## Generate a config

Use the generator below to create a fresh X25519 keypair, UUID, and short ID,
then copy the server inbound JSON and the client share link. Everything is
computed **in your browser** — no keys or links are sent anywhere.

<RealityConfigGenerator />

<Callout type="info">
  The **private key** belongs only on your server. Share the generated
  `vless://` link (which contains the **public** key) with clients.
</Callout>