Activity Tokens

Tokens

Activity tokens are typed values that travel on object flows. They are the application data carried through an Activity; control flows carry control only. An action produces tokens with Output or OutputRange and reads routed inputs with GetTokensOfType<TToken>().

flowchart LR
    produce(Produce values) -->|int tokens| select{Decision}
    select -->|even| sum(Sum values)
    select -->|else| report(Report values)

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Mermaid approximation: this diagram shows the model's routing, not a complete UML Activity notation. Rounded boxes represent actions; edge labels identify token types or guards. Mermaid does not provide native Activity node semantics.

Producing and receiving tokens

.AddInitial(node => node.AddControlFlow("Produce"))
.AddAction(
    "Produce",
    async c => c.OutputRange(new[] { 2, 5, 8 }),
    node => node.AddFlow<int, DecisionNode<int>>())
.AddDecision<int>(decision => decision
    .AddFlow("SumEven", flow => flow
        .AddGuard(async c => c.Token % 2 == 0))
    .AddElseFlow("ReportOther"))
.AddAction("SumEven", async c =>
{
    var values = c.GetTokensOfType<int>();
    await reports.WriteSumAsync(values.Sum(), c.CancellationToken);
})
.AddAction("ReportOther", async c =>
    await reports.WriteValuesAsync(
        c.GetTokensOfType<int>(), c.CancellationToken))

The generic argument on AddFlow<TToken> describes the object type carried by that edge. A flow guard can filter tokens; a transformation can change the type before they reach the target. Tokens may also be forwarded using PassTokensOfTypeOn<TToken>() or PassAllTokensOn() where the node/context API supports it.

Structured nodes pass selected parent tokens through Input Nodes, and return data through Output Nodes. Use a Data Store Node when a graph must retain tokens across later activations. See Data Flow and Implicit Fork and Join for routing and token reuse semantics.