Reasoning effort becomes a standard dial in AI coding tools

Anthropic expanded Opus 5's reasoning-effort ladder to five levels and told users to sweep across them instead of locking in one default. Two coding harnesses matched the move within four days.

That shift makes per-request compute allocation, not model selection, the primary cost lever in agentic coding tools. The setting you pick for a single request now matters more than which model backs it.

Antigravity CLI v1.1.5 added an /effort slash command that changes reasoning depth mid-session, per its release notes. Cursor Router exposed the same tradeoff under a different name, routing modes that trade cost for depth without swapping models.

None of the three say how the ladder maps to price. Antigravity's release notes don't mention cost at all, and neither Anthropic's expanded ladder nor Cursor's routing modes settle whether deeper reasoning costs more per request.

Expect effort to become a first-class field in agent definitions and CI configs, the same way model IDs are now. And expect to regret any config that hardcodes it.

Three harnesses landed the same control within four days of each other, which is what makes this look like convergence, not one vendor copying another.