The share number itself is a snapshot, but the trajectory is the real story. Three years ago OpenAI had near-monopoly distribution in enterprise; today it is one of three frontier providers that procurement teams routinely shortlist together. Anthropic's gains have come from the workloads where Claude's long-context, tool-use, and code-generation behaviour outperforms - the same workloads that show up most often in the Vercel AI Gateway April snapshot we covered earlier this week.
For founders, the read is that vendor pinning is now actively expensive. Whichever provider you locked into in 2023 is unlikely to be the right pick for the workload mix you have today, and the fragmentation is structural rather than temporary. Routing - whether through Vercel AI Gateway, OpenRouter, or your own router - has shifted from "nice optimisation" to "default architecture", and procurement teams that still buy a single seat-based deal are leaving real spend on the table.
If you are still on a single-vendor enterprise contract for LLMs, model the unit economics of routing across Anthropic, OpenAI, and Google before your next renewal. The 13-point swing in three years is the kind of move that does not reverse cleanly.
