About

What thisactually is

Sour Client is a desktop launcher and mod set for Minecraft: Java Edition 1.8.9. It launches the game you already own, on the account you already have, with performance work and quality-of-life features built in. This page explains what it does, what it touches, and what it deliberately does not do.

The product

A launcher and a client, in one

What it is
Launcher
A Windows desktop application. It signs you in to your Microsoft account, downloads the official game files from Mojang, and starts Minecraft 1.8.9 with the Sour Client mod loaded.
Client
A Forge mod for 1.8.9 that adds rendering and performance work, a configurable HUD, keybinding, cosmetics, and optional server-specific overlays.
Game version
Minecraft: Java Edition 1.8.9 only.
Platform
Windows 10 and 11, 64-bit.
Cost
Free. An optional paid tier covers cosmetics only and changes nothing about how the game plays.

Authentication

How signing in works

Sour Client uses the standard Microsoft and Xbox Live sign-in chain. You sign in to Microsoft directly, in Microsoft's own interface. The launcher never renders a password field and never handles your password.

01

Microsoft

You sign in through Microsoft's own page, either in your browser via a loopback redirect with PKCE, or by entering a device code Microsoft shows you. The launcher receives an access token and a refresh token. It never sees what you typed.

02

Xbox Live

That Microsoft token is exchanged for an Xbox Live token, using the xboxlive.signin and xboxlive.offline_access scopes and nothing more.

03

XSTS

The Xbox Live token is exchanged for an XSTS token authorised for Minecraft services.

04

Minecraft

The XSTS token is presented to Minecraft services, which confirms the account owns the game and returns your profile. If the account does not own Minecraft: Java Edition, sign-in stops here and the game does not launch.

Where things are kept
Your tokens
Stored locally, on your own device, in the launcher's data folder, so you stay signed in between sessions. They are sent only to Microsoft, Xbox and Mojang endpoints.
Your password
Never seen, never handled, never stored. It is typed into Microsoft's interface, not ours.
Our backend
Receives no Microsoft token and no password. The optional cosmetics service identifies you by the standard Mojang server-join handshake, the same mechanism a Minecraft server uses.
Game files
Downloaded directly from Mojang's official servers at first launch, exactly as the vanilla launcher does. Sour Client does not host, bundle, or redistribute any Minecraft game file.

Full detail on what is collected and retained is in the Privacy Policy.

Boundaries

What it does not do

Never
No password handling
There is no Sour Client password, no separate account to create, and no credential form anywhere in the launcher.
No game piracy
An account that owns Minecraft: Java Edition is required. There is no offline bypass, no cracked mode, and no way to play without owning the game.
No gameplay advantage
Sour Client does not ship reach extension, aim assistance, X-ray, auto-clicking, or any similar cheat. Everything sold is cosmetic.
No telemetry
No analytics, no advertising identifiers, no behavioural profiling. Logs and diagnostics stay on your machine.
No resale of game content
Nothing owned by Mojang or Microsoft is sold, rehosted, or redistributed.

The developer

Who builds it

Contact
Developer
sourama, an independent developer based in New Zealand.
Email
[email protected]
Official site
sourclient.com. This is the only official distribution channel.
Status
Pre-release. The client is in active development and is not yet publicly downloadable.

Privacy Policy

Everything collected, why, where it is stored, and how long it is kept.

Read →

Terms of Use

The rules for using Sour Client, including account and cosmetic terms.

Read →

Third-Party Notices

Every open-source component in the launcher and the client, with its licence.

Read →

Affiliation

Not an official Minecraft product

Sour Client is an independent project. It is not approved by or associated with Mojang Studios or Microsoft. Minecraft is a trademark of Mojang Synergies AB. Sour Client does not include Minecraft, and you need to own the game to use it.

Read the full disclaimer →