Stop wiring references just to send an event.

TagEventBus lets senders and receivers meet on a Gameplay Tag instead of holding references to each other. Broadcast on `Combat.Hit`, listen on `Combat.Hit`, and widgets, actors, and subsystems communicate without knowing about each other. When an event does not arrive, the in-editor debugger shows who broadcast it, how many listeners it reached, and who is listening on that tag.

What you get

• Communication by tag on a global bus (GameInstance) and optional local buses on actors.

• Typed payloads: any USTRUCT, through Instanced Structs in Blueprints and by const reference in C++.

• Sticky events: late listeners can opt in to receive the last value, with an optional time-to-live. Capture and restore retained values in your save/load flow.

• In-editor debugger with Overview, Live, Inject, and Contracts tabs. Inject lets you test a receiver before the sender exists.

• Delivery control: hierarchical matching, priority, one-shot listeners, throttling, tag queries, pause/resume, listener groups, consumption, and deferred dispatch with coalescing.

• Automatic cleanup of managed listeners and C++ RAII subscriptions.

• Optional modules: request-response with timeouts and cancellation, and per-tag event contracts (Off, Warn, Ensure, Block) checked outside Shipping.

Built for development and shipping

• Full C++ source. No third-party code or marketplace dependencies.

• The bus stays in Shipping builds; the debugger, history, statistics, and contract validation are compiled out.

Good to know before you buy

• Game Thread only.

• No built-in replication: use Unreal's networking between server and clients, then broadcast locally.

• Every tag must be registered in the project's Gameplay Tag list.

• The debugger tracks the global bus only.

• Enabling TagEventBus also enables Epic's GameplayTagsEditor plugin, which ships with the engine. It is editor-only (the debugger's tag pickers use it)

• No example project: the documentation includes ready-to-paste Blueprint graphs.

• Windows (Win64) only.

• AI disclosure: the code is the author's own. Generative AI tools helped polish parts of it and, mainly, write the documentation; every change is reviewed by the author and covered by the test suite.

Documentation and support

• Documentation: https://stillcooking.dev/en/products/tageventbus/docs/

• Support: https://stillcooking.dev/en/support/

• Bug reports and discussions: https://github.com/StillCooking/TagEventBus