Temporal raises $550M at a $12.55B valuation and reports 1.9 trillion billable actions in August

Sources: Temporal announcement, HN discussion
Summary: Temporal states 1.9 trillion billable actions in August, more than 4,300 paying customers including OpenAI, Snap, NVIDIA and JPMorgan Chase, and open source installs past 43 million, up 134 percent since December 2025. The Series E is co-led by Lightspeed and lands seven months after a $300M Series D at $5B, and OpenAI's VP of Infrastructure is quoted saying OpenAI built a durable orchestration framework powered by Temporal. Every figure here is the company's own and none is independently audited.
Why it matters: Temporal is the durable execution layer under a growing share of long-running agent workloads, which is the engineering reason to record the round rather than the valuation.