An in-depth update regarding the temporary outage of XMCL's Peer-to-Peer (P2P) online multiplayer service, how the launcher interacts with `xmcl-web-api`, why Deno API limits were exhausted, and our current backend migration.

---

<PostDetail>

:::warning SERVICE NOTICE

**P2P Online Room Hosting is Temporarily Unavailable.**

When attempting to create or join P2P rooms in XMCL, you may encounter `multiplayer_room_request_failed` or WebSocket connection errors. Local LAN play and joining dedicated servers remain **100% functional**.

:::

## Overview

Over the past few days, many players have reported that creating or joining online multiplayer rooms through X Minecraft Launcher (XMCL) is currently failing.

We want to provide full transparency by explaining how XMCL's P2P multiplayer system works behind the scenes, how the launcher communicates with our backend ([`xmcl-web-api`](https://github.com/Voxelum/xmcl-web-api)), why changes in Deno Deploy's free tier quotas caused this service interruption, and how we are fixing it.

---

## How XMCL P2P Multiplayer Works

XMCL's P2P multiplayer allows players to host single-player Minecraft worlds and open them to friends over the internet **without port forwarding, external server hosting, or third-party VPN tools like Hamachi**.

```

+------------------+ Signaling & Ticket Broker +------------------+

| | (https://api.xmcl.app / Web-API) | |

| Host Launcher | <======== WebSocket Control ========> | Guest Launcher |

| | (SDP & ICE Exchange) | |

+------------------+ +------------------+

| |

+================ Direct P2P WebRTC Connection ===============+

(Host-Star DataChannel Mesh)

```

### 1. Launcher Architecture & `xmcl-web-api`

The launcher (`xmcl-electron-app`) uses `@xmcl/wrtc-multiplayer` and `PeerService` to manage room life-cycles and peer connections:

- **Host Room Creation**: The host issues a request to `POST /v2/multiplayer/rooms`. The backend validates the player's XMCL session token and issues a 5-minute single-use admission ticket and WebSocket URL.

- **Control Socket**: The host opens a persistent control WebSocket (`GET /v2/multiplayer/rooms/:roomId/socket?ticket=...`).

- **Guest Admission**: Guests request an admission ticket via `POST /v2/multiplayer/rooms/:roomId/join` and connect via WebSocket to exchange WebRTC offer/answer SDP payloads and ICE candidates.

- **Direct P2P DataChannels**: Once SDP negotiation finishes, guests close their temporary WebSocket connection. All Minecraft game traffic and mod/file transfers flow **directly between peers** via WebRTC DataChannels and a local virtual port bridge (`http://localhost:25566/files/...\`). Game traffic is **never** relayed through the web API servers.

### 2. Network Topology: Host-Star Mesh

Rather than forcing every guest to connect to every other guest, XMCL uses an efficient **Host-Star topology**:

- The **Host** maintains a persistent control socket to accept new guest handshakes immediately.

- **Guests** establish WebRTC links exclusively with the host.

- STUN/TURN servers (`/rtc/official`) assist in discovering public IP addresses and traversing complex home NATs/routers (via UPnP / NAT-PMP).

---

## The Root Cause: Deno API Quotas & Limit Exhaustion

Our primary public deployment of [`xmcl-web-api`](https://github.com/Voxelum/xmcl-web-api) relied on **Deno Deploy** (using Deno KV and native WebSocket `BroadcastChannel` signaling).

Recently, Deno instituted strict platform policy updates and reduced free-tier quotas across Deno Deploy and Deno KV:

1. **Exponential User Growth**: As XMCL's player base expanded, the sheer volume of daily WebSocket room creations, authorization tickets, and real-time signaling exchanges increased dramatically.

2. **Quota Exhaustion**: The total API usage generated by active P2P multiplayer sessions **surpassed 100% of all Deno free-tier limits**.

3. **API Rejection**: Deno Deploy began rejecting incoming `/v2/multiplayer/rooms` API requests and closing WebSocket connections.

Because the signaling server acts as the essential "handshake broker" required for WebRTC peers to exchange ICE candidates and establish direct connections, room creation became unavailable worldwide.

---

## What We Are Doing: Migration to Cloudflare Durable Objects

We are actively completing a major architectural migration of [`xmcl-web-api`](https://github.com/Voxelum/xmcl-web-api) away from Deno Deploy to **Cloudflare Workers with `MultiplayerRoom` Durable Objects**.

### Why Cloudflare Durable Objects?

- **Global High Availability**: Durable Objects provide stateful, low-latency WebSocket signaling nodes globally distributed across Cloudflare's edge network.

- **Zero Third-Party Quota Blocks**: Eliminates the strict free-tier API rate limits that broke the Deno deployment.

- **Enhanced Security**: Admission tickets (`XMCL_MULTIPLAYER_TICKET_SECRET`) expire after 5 minutes and single-use validation prevents room hijacking.

- **Improved TURN Infrastructure**: Expanded STUN/TURN relay server pools for higher NAT traversal success rates.

---

## What Players Should Do

:::tip PLEASE WAIT PATIENTLY

We kindly ask all players to **please wait and be patient** while we complete the backend migration and deploy the new signaling infrastructure.

:::

While online P2P room hosting is being restored:

- 📶 **Local Area Network (LAN) Play**: Playing with friends on the same physical Wi-Fi or home network operates via local multicast/ssdp discovery and remains **100% functional**.

- 🌐 **Dedicated Minecraft Servers**: Joining standard public or private Minecraft servers via IP address or domain is **completely unaffected**.

---

## Announcement Channels

Once the new Cloudflare Durable Objects backend is fully deployed and verified, **we will immediately announce service restoration** on our official communication channels:

- 📰 **XMCL Blog**: Updates and post-mortems will be published directly here in our journal.

- 💬 **Community Channels**: Announcements will be posted in our **Discord server** and **Reddit community**.

*(Note: Official status announcements are published via our blog and social channels rather than GitHub repository issues).*

We sincerely apologize for the disruption to your multiplayer gaming sessions. Thank you for your patience, support, and understanding while we upgrade our infrastructure!

blog -https://xmcl.app/en/blog/posts/p2p-multiplayer-status

0.65.1

🐛 Bug Fixes & Patches

• microsoft auth xbox error guide (#1601) (62a98bfa35bfe48b20bf7b9a571ed002224288c7)
• runtime: preserve existing Steam shortcuts (cdcc6e6be2696995f0fefff7da97efd5b3f4532f)
• select and detect Zulu JRE by host libc (musl vs glibc) (#1617) (04c8c70aedd8ea60a783083855f577c266c9aeb4)
• Accept hyphenated Microsoft email addresses during login (#1610) (89fedf11c993b580b0403b730a808216f3e0b984)
• auth: resolve 24-hour Microsoft account reauthentication issue (cc3896a6403a5a3be5549336627e1da35f910530)
• unblock setup completion (7b6d7992da645e2df21e2c9223881f7bcdf8f168)

🏗️ Refactors

• implement gamepad control enhancements, UI toggles, and contextual fixes (#1611) (76f6403e256cc2e190dd6b6ac38723edf55e6546)
• add Xbox Live presence status support for friends (#1615) (f861c1026c410eb2be9f8d7a9cb8f585efe3af56)

🚀 Features

• telemetry: capture safe Java runtime resolve diagnostics (fc04a1de7bc44c9eb6d099b9297f720ca3edefa2)

🐛 Bug Fixes & Patches

• runtime: type zip cache correctly (d071d3c96a13ec7b458f79a8da5b58a94123bcca)
• Regression of drop file in new electron (5ab494229e22331839d783aa026d615028f16384)
• watcher: release stale filesystem watchers (67bdfab8b9f4f1b203c8f088facebfede49c15dd)
• modpack: reuse ZipManager inode aliases (34701f9267ba381ecedf10a06634e2723a5da430)
• instance: detect case-colliding modpack paths (d6078263b1791c236d69e28e41b3292ecde95566)
• modpack: skip missing CurseForge files (6cd28fb6919ea98d92a148aa6bc2b65bfc91840f)
• network: preserve multipart uploads in Electron (19c4e6c789373f9f9f11d22ec72f1f3d47a3d4f0)
• telemetry: track end-to-end install outcomes (6eee5f64a0fadfb952b1517dda9ac64c9195e791)
• user: handle expected skin upload failures (c353022cb57aa80ff109a209f7985d0c176be5dd)
• installer: recover range downloads and diagnose processors (b7354d3e69110e699ee566dc990a6f3680fcd312)
• java: add Zulu Java 25 fallback runtimes (9c81689c36f4e26104db835c350ece329051c36b)
• java: gate x64 runtime fallback on WOW64 (51a472b109764a27bdf1768c10f2056ac99a16df)
• java: recover when the official runtime cannot start (8e4ae3dbea609c7ab815a96e934dcb0793162c91)
• auth: treat known network and friends failures as exceptions (055ab1f977943b1f03de9dcb1aa8f44bc9c8f44c)

new site - https://xmcl.app

🐛 Bug Fixes & Patches

• Fix CurseForge downloads leaving instances incomplete (#1583) (be3272b5c7c429825b4fabc094815b3bc5fd0881)
• Fix Multiplayer On LAN group creation (#1581) (72798f3179d60d6124907b813d2f0622a1cc9da5)
• avoid DRI_PRIME for NVIDIA offload (#1571) (f38167848d254760fbabe805477b085ca942c1ec)
• Fix perf issue due to lots of screenshot (aa3529ea80df10f3ce2cfcfb3e09512955f8e278)
• fall back to X11 when Wayland socket is unavailable (b94bc9b9378953b399903918fa184ac350fa949b)
• electron: resolve llhttp-wasm and iconv-lite from parent directories if called from subfolder workers (c81ebe73710ee85108961caceac90243186bc5d3)

🏗️ Refactors

• Make install parallel (de916c2bf8218012e1af79ca6bb34a7c8bda8ebd)

🚀 Features

• ui: group context menu items into sections (81bc438f6dece42d062fe322fabadd405b7b6f4c)
• add a globally preferred Java setting (52cb36c7e85b21bf286cde238ce04a828a736eb6)
• add instance to a group from the sidebar context menu (f9cc2ee23493be0efd23b9ba546ce7f0e0e02f0f)
• ui: cascade enable/disable of mod dependencies (a783ceeb4267304c6319bd3efc162124a6b23a52)
• default font picker to system font folder (c6141124541ec0318234f6a9390c153714df7e57)
• choose shared-folder links when creating an instance (32696bc74f8029003a58f5a8a036d1d3c022618b)
• ui: launcher-owned collections and favorites (bd153fb847df0887a7d7074343e7e9196ab6f2d6)

🐛 Bug Fixes & Patches

• ui: hide group-installed button in local mod view and fix active state (bfe85dca0dda58eb00944bad467865340c313055)
• support MultiMC patches in local imports (e14d54ee2b0caf2ae18b297f62a5442c7367164f)
• linux: keep discrete GPU launch environment consistent (#1565) (3444a44f2e76e49cbdd39b888c1a973c432c26b3)
• add 9 new locale translations and update tr/ko (#1566) (e9a13fc40a2df421ed5ef25b57b99ba74a94e37a)
• ui: responsive store layout with pinned search bar on narrow screens (957c994e228d282146108b92718d8998ac607dcd)
• ui: block instance creation without an effective name (c2875c50409e81b2e64f849c9b4436816b842cc8)
• network: fall back after API error responses (9f858f47e707b414b3002532ba17b582919b6a9f)
• ui: tolerate legacy server status without players (7cb145289a70b48bb127e83a5677a5fa7dc678cb)
• sqlite: recover lowercase database lock errors (dc14b9f2e69e5740927c2ccefe987086576a8fbd)
• Add try to yggdrasil loading (86e80efe64387fb5edc1bbeb21d0e63bb7a1f231)

🏗️ Refactors

• ui: smarter shared mod group rules sync (810736ec7073d92e6bba0679f18e6265da0df52d)
• Allow explicit multi-select (578c5483e3bc1ac719115eb0e82ecf10b7ae11bb)
• group mod loader and Modrinth environment filters in a single row (1048b007d2dbc2668a73033a59e496fa3019c4a1)
• sqlite: replace node-sqlite3-wasm with node:sqlite (b1068d32652859f70782c2c96b6617b37a9d1795)

Flathub check blue

We are thrilled to announce that X Minecraft Launcher (XMCL) is now officially verified on Flathub! You will now see the blue verification badge next to our launcher on the store.

👉 Check us out at: app.xmcl.voxelum on Flathub

Our Journey to Verification

We couldn't get through before because a lot of things were missing, but we figured it out, and now—hello, verification!

Getting verified on Flathub requires proving the ownership of the domain associated with the App ID. Since our App ID is app.xmcl.voxelum, we needed to demonstrate control over our domain and address some metadata checks required by Flathub's modern AppStream validator.

Here is what we solved to make this happen:

1. Domain Ownership Verification

Flathub validates developers by looking for a unique verification token at a specific secure URL. We added our verification token under the .well-known/ directory of our official website (xmcl.app):

• URL: https://xmcl.app/.well-known/org.flathub.VerifiedApps.txt

Once the site deployed the token, Flathub verified the domain xmcl.app immediately.

2. Refining AppData / AppStream Metadata

To comply with Flathub's strict quality standards, we updated our app description and metadata rules inside app.xmcl.voxelum.metainfo.xml:

• Friendly Summary: Simplified the app summary to "Play and manage Minecraft" (under 35 characters, non-technical, and free of articles or redundant app name mentions).
• Asset Updating: Replaced all old screenshots in the metadata package with fresh, high-resolution snapshots of the latest XMCL interface showcasing our multi-instance manager, modpack explorer, mod downloader, server dashboard, and game creation flow.

What This Means For You

The blue checkmark on Flathub means you can download and update XMCL with full confidence, knowing the Flatpak package is verified and maintained by the official development team.

Thank you to everyone in the community for your continued support!

Hey everyone! I'm u/Banerbansa, a founding moderator of r/XMCL.

This is our new home for all things related to {{ADD WHAT YOUR SUBREDDIT IS ABOUT HERE}}. We're excited to have you join us!

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How to Get Started

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3. If you know someone who would love this community, invite them to join.
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Thanks for being part of the very first wave. Together, let's make r/XMCL amazing.

I was working in (dev); sometimes there might be a glitch effect, but it only shows up in the recording.

I don't use a gamepad very often (or rather, rarely), so I've been dragging my feet on this. But by creating this, we'll provide REAL support for the Steam Deck—unlike PrismLauncher, which just added a text mention but failed to implement even basic gamepad support.

I’ve now reached the final stage, and after version 6.0.0, gamepad support will be 100% ready.

I’ll answer a few quick questions right away:

* Will there be support for other gamepads? - Yes, there will be support for Xbox, PS5, PS4, and PS3 (PS2 and PS1 aren’t really supported), and once it’s released, I’ll try to add support for Nintendo and Wii

* Do I need a license to use this feature? - No, it’s free

* Is there keyboard support? - There used to be... but I removed it at CI010’s request

Here are his words

* Is the mod safe to install? - Don’t blame us—blame Modrinth—that’s where the mod is downloaded from

* Can I choose not to install the mod? - Yes, just press “B”

/If you have any questions or suggestions, let me know—I’ll look into them and make improvements/

In the meantime, here’s my PR: https://github.com/Voxelum/x-minecraft-launcher/pull/1514

1. It will appear if a bedrock is purchased

Hello everyone! I wanted to tell you that we recently started a new project and finished it. In the new version you will be able to play the Bedrock version (though only on Windows), there will be no physical support for Linux and Mac, and it is also not possible to implement it. Also, Bedrock is available only to those who have purchased a license.

2. It will be normal if this happens, you need to click download and wait, it downloads through winget bedrock.

check and you can play :3

Questions, design, themes, ideas, we are developing a launcher that wins in functionality, design and most importantly, that this is not a fork of MultiMC or another launcher - the design was made from scratch, the functionality is difficult. The main goal on our server is to help people get pleasant emotions from the launcher, as well as answer questions and show small updates

https://preview.redd.it/mvgdb074139h1.png?width=493&format=png&auto=webp&s=ebcbc0ef98a261eab49dfa35c548a442a881d0d5

I want to tell everyone that we are now working normally on SteamDeck (and before that too), but now a very nice part is being implemented even for simple gamepads - LAUNCHER CONTROL VIA GAMEPAD.

I am writing this post so that you can prepare your consoles for the tests.