Fighting Game · Guides & deep dives

Mod Multiplayer Compatibility

required version, provider, provider id, package hash, estimated download size, and required flag.

4sections1 minread
Markdown source
On this page

Task: TODOS.phase-72.72.14.2.13

V2 mod multiplayer compatibility is a join preflight for modded sessions. The host specifies required mods, the client compares that list against local mod state, and the join plan auto-downloads missing mods, updates mismatched mods, enables installed disabled mods, or blocks join when requirements cannot be satisfied.

Policy#

FV2ModMultiplayerCompatibilityPolicy is created by BuildDefaultModMultiplayerCompatibilityPolicy and enables:

  • exact host/client version matching
  • auto-download for missing required mods
  • auto-update for mismatched installed mods
  • auto-enable for installed disabled required mods
  • join blocking until required mods are ready
  • size limits for auto-downloads

Host And Client State#

FV2ModMultiplayerRequiredMod records the host-required mod id, display name, required version, provider, provider id, package hash, estimated download size, and required flag.

FV2ModMultiplayerClientMod records the client's installed version, provider, provider id, installed state, and enabled state.

Join Plan#

EvaluateModMultiplayerCompatibility returns an FV2ModMultiplayerCompatibilityReport. The report exposes whether the client can join now, can join after downloads, requires auto-download, or requires client action. It also includes warning/blocking counts, issues, and actions.

Missing required mods with downloadable providers create DownloadRequiredMod actions. Version mismatches create UpdateInstalledMod actions when the provider can supply the host version. Disabled installed mods create EnableInstalledMod actions. Missing session ids, malformed host mod entries, unavailable providers, oversized downloads, or disabled auto-download settings create BlockJoin actions.

Verification#

Run:

bash
python3 V2/ue/Tools/check-v2-mod-multiplayer-compatibility.py
python3 -m json.tool V2/ue/Content/V2/Modding/ModMultiplayerCompatibility_V2_Contract.json

The focused checker verifies runtime types, host required mods, client mod comparison, auto-download on join, auto-update before join, auto-enable before join, join blockers, automation assertions, docs, CI/Horde wiring, and TODO evidence for 72.14.2.13.