elelem v0.4.0 — Run/RunInto, and streaming is a choice Breaking: Request.Complete, Request.Stream and Request.CompleteInto are gone. Run(ctx) and RunInto(ctx, &dst) are the whole launcher surface. Complete -> Run, CompleteInto -> RunInto, Stream(ctx, fn) -> OnDelta(fn).Run(ctx). The one behaviour change to check: Complete did not send tools even when the request carried them; Run sends whatever is configured. New: WithStreaming(bool) on client and request, for compat backends that cannot serve a streaming call. Driver gains Complete -- the same request with streaming off, feeding the finished response through the same delta callback, so callbacks, tool assembly and the Response are unchanged. A third-party driver must implement it. Capabilities.StreamingUnsupported reports a provider that cannot stream at all.