Matt
8e00526d27
Microsoft access tokens have a ~1 hour TTL. The launcher cached the MSession once at sign-in and re-used it on every Play click, so leaving the launcher open for >1 hour and then hitting Play sent stale credentials to MC -- Mojang's session check on the server then rejected the join with "Invalid session". Fix: in DoLaunchAsync, before assembling the MC launch command, call _auth.TryAuthenticateSilentlyAsync(). XboxAuthNet's silent flow uses the cached refresh token (~14 day TTL) to mint a fresh access token transparently. On success ApplySession swaps in the new MSession and we launch with valid credentials. On failure (refresh token also stale) the launcher prompts the player to sign in again -- they keep the launcher open, hit Sign In, no MC restart needed. No new dependencies, no UI change beyond the brief "Refreshing session..." status line, no perf cost beyond the ~500ms HTTP roundtrip to Microsoft each launch. Bump the launcher version in launcher/ModpackLauncher.csproj before publishing so old launcher installs see the upgrade banner.
Brass & Sigil
Self-hosted Minecraft modpack distribution + administration system. Three components, one repo:
brass-and-sigil/
├── launcher/ ← Avalonia desktop client (Windows .NET 8)
│ Auths with Microsoft, syncs the modpack, launches the game.
├── server/ ← brass-sigil-server daemon (Linux .NET 8)
│ Wraps the MC subprocess, exposes the admin web panel,
│ syncs mods, runs backups + BlueMap, handles whitelist.
├── pack/ ← Modpack content
│ ├── pack.lock.json Source of truth for mod versions / URLs / hashes
│ ├── tweaks/ Hand-written data-only tweak source
│ └── overrides/ Build output / hand-placed local files (gitignored)
├── scripts/ ← Build + deploy entry points (run from repo root)
│ ├── Update-Pack.ps1 Refresh pack.lock.json from Modrinth/CurseForge
│ ├── Check-Updates.ps1 Non-mutating "what's new?" report
│ ├── Build-Tweaks.ps1 Compile tweaks/ into pack/overrides/mods/*.jar
│ ├── Build-Pack.ps1 Generate manifest.json from the lockfile
│ └── Deploy-Brass.ps1 One-shot build + deploy everything
└── docs/ ← Operational notes, deploy runbook, schema docs
Quick start
# Pull dependencies, copy and edit the deploy profile
git clone <remote> brass-and-sigil
cd brass-and-sigil
Copy-Item scripts\deploy.config.template.ps1 scripts\deploy.config.ps1
notepad scripts\deploy.config.ps1 # fill in deploy share, SSH host, etc.
# Build + deploy everything in one go
.\scripts\Deploy-Brass.ps1
deploy.config.ps1 is gitignored -- local values never get committed.
Component reference
| Component | What it does | Technology |
|---|---|---|
launcher/ |
Friend-distributed client. Auths with Microsoft via WebView2 + XboxAuthNet, downloads mods, launches Minecraft. Single self-contained .exe published from publish/. |
Avalonia 12 + CmlLib.Core |
server/ |
Daemon running alongside the MC process on Linux. Hosts a Kestrel web panel for admin (cookie-auth, rate-limited), bridges RCON, runs scheduled backups + BlueMap renders, handles whitelist requests. | ASP.NET Core minimal APIs |
pack/ |
Lockfile-driven modpack content. pack.lock.json resolves mod slug → URL+SHA-1; Build-Pack.ps1 walks it and produces manifest.json for the launcher and the server-tool to consume. |
PowerShell tooling |
Workflow
- Bump mod versions:
.\scripts\Update-Pack.ps1(queries Modrinth + manual CurseForge entries). - Sanity-check:
.\scripts\Check-Updates.ps1for a non-mutating availability report. - Edit tweaks under
pack/tweaks/<name>/if you're changing recipes / loot / etc. - Deploy:
.\scripts\Deploy-Brass.ps1-- builds launcher + server, regenerates manifest, mirrors everything to the deploy share, scp's the server binary.
Secrets / config files
| File | Tracked? | Notes |
|---|---|---|
launcher/launcher-config.template.json |
✓ | Empty placeholders, public-safe |
launcher/launcher-config.json |
✗ | Local override; merged into the published exe at build time if present |
server/deploy/server-config.example.json |
✓ | Template; rename to server-config.json on the server with real values |
server/deploy/server-config.json |
✗ | Production config; lives on the server only |
scripts/deploy.config.ps1 |
✗ | Local deploy profile (paths, SSH host, share location) |
License
See LICENSE.