Graphite’s $52M Series B and the Diamond AI reviewer launch
March 2025: Accel-led Series B and Diamond as a standalone AI PR reviewer (later rebranded into Graphite Agent).
Source: Graphite raises $52M and launches Diamond — Graphite
Graphite’s Series B post launches Diamond as a standalone AI reviewer for any GitHub org repo, alongside the stacked-PR/merge-queue platform. A later note on the page records the Oct 2025 rename into Graphite Agent—useful historiography for the category.
Why it matters for code review
Graphite’s bet is that stacking + AI review + merge queue is one outer-loop product. Whether Diamond/Agent is best alone or only inside Graphite is still the buyer’s question; the post is honest that the full platform is where it compounds.