Amp killed named modes for a single effort dial, and baked cross-model review into the default loop

On July 9, Sourcegraph's Amp deprecated its smart/deep/rush/large modes and replaced them with one four-position dial: low, medium, high, ultra. The dial binds reasoning effort to a difficulty setting, so you stop learning a tool's private vocabulary and just turn the "how hard should this try" knob (jls42.org).

Two design choices inside that make it worth your attention. First, the low tier defaults to Z.ai's open GLM-5.2, which Amp bills as "the strongest open model in agentic coding," with expensive frontier models acting as advisors. High and ultra put frontier models in the primary writing seat. So cheap open models do the routine drafting and frontier compute is reserved for the hard passes, which is exactly the cost structure I've been hand-rolling in my own projects.

Second, and this is the real one: every level now ships an "oracle" second opinion. At high, one frontier model writes and another reviews. At ultra, the roles flip. Cross-model peer review is now the default loop, not a manual habit.

This is a convergent pattern, not one vendor's gimmick. Claude Code's /code-review was specifically tuned for Opus 4.8 across effort levels, and its effort-level control predates Amp's dial (MCP.Directory). Two tools, independently landing on the same two ideas: collapse modes into a monotonic effort slider, and pair a writer model with a reviewer model. The bet underneath it is that one model's blind spots get caught cheaper by a different model than by throwing more compute at the same model. I think that bet is correct. I've been manually running "have a second model review this diff" for months and it catches things single-model iteration never does.

What to do now, and you don't need Amp to do it. Adopt effort-tiered, oracle-reviewed loops today. Route your drafting and high-volume subagent work to a cheap open model like GLM-5.2 or Kimi-K2.6 (Ollama now supports both with one command). Pay for frontier compute only on the correctness-critical passes. And on anything risky, a refactor across module boundaries, security-sensitive logic, wire a second model to review the first one's output before you ship. Thorsten Ball's framing fits here: 2026 is the year agents and codebases melt together, and judging code becomes the core skill (Register Spill). The oracle pattern is that skill, automated.