Why it matters

Parallel tools shape latency. Modern LLMs support parallel; ADK must too.

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The architecture

LLM returns list of tool calls.

Execute in parallel (CompletableFuture, structured concurrency).

Parallel tools flowTool callslist from LLMParallel executeCompletableFutureCombine resultsreturn to LLMStructured concurrency (Java 21+) simplifies parallel tool execution
Parallel tools.
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How it works end to end

CompletableFuture: allOf.

Structured concurrency: cleaner in Java 21+.

Timeouts per call.

Aggregate results.