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Each trigger occurrence begins in its own context. Cross-context operators create child contexts that inherit the selected parent histories without copying application values into operator state.

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.keyBy()

.keyBy(getKey, options?) immutably assigns an encoded partition key to a signal. The synchronous key function must be pure.
The optional ttl excludes an unmatched occurrence from future coordination after the duration elapses. It does not promise immediate physical deletion. Calling .keyBy() replaces a previous keyed or global partition annotation.

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.globally()

.globally() explicitly places every occurrence in one shared partition for each operator that consumes it:
Calling .globally() replaces a previous keyed or global partition annotation. Prefer .keyBy() when independent entities should not affect each other.

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Partition preservation

Operators that preserve one source value also preserve its explicit keyed or global partition. Operators that combine values require an explicit partition on their result before another cross-context operation.

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correlate()

correlate(streams, options?) eagerly matches one occurrence from every keyed stream. Matching uses exact encoded keys, consumes occurrences one-to-one and oldest-first, and creates a child context containing every selected parent history.
Consume the original signals downstream. The returned Signal<null> is only an explicit match boundary for lower-level compositions. { ordered: true } additionally requires occurrences to arrive in array order; unordered matching is the default. TypeScript requires at least two keyed streams. The same durable signal origin cannot occupy multiple positions because one occurrence cannot satisfy two roles; collect distinct occurrences first when that is the intended behavior. A locally filtered or partitioned path that closes contributes no occurrence and does not close future correlation.

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collect()

collect(signal, count, options?) consumes occurrences FIFO and emits an array for each complete batch. count is a positive integer or a signal carrying one.
A keyed source maintains one collection per key; .globally() creates one shared collection. Signal-derived counts participate in matching, so occurrences batch together only when their resolved count values match. Locally closed inputs contribute no occurrence. The result is an ordinary Signal<T[]>. When selected parents contain conflicting values for another signal, the last parent supplies that value by default; pass { inheritConflictingValuesFrom: "first" } to choose the first. This does not change FIFO result order.

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each()

each(arraySignal, section) creates one inherited child context for every array position. The synchronous section receives a Signal<T> for its item.
Return a signal to gather results in source-array order, regardless of completion order. A failed item fails the gathered result; a closed item closes it. Returning nothing fans out the side effects without creating a join signal. An empty input gathers to []. See burst control to coordinate occurrences by time, or route and scope work for dependencies within one context.