OpenRouter Claude Opus 4.6: xhigh variant ignored, defaults to high

[khaledfouad0]

Bug Description

When configuring Claude Opus 4.6 via OpenRouter (openrouter/anthropic/claude-opus-4.6) with variant: "xhigh" in oh-my-openagent config, the variant is downgraded to high at startup. Manually selecting xhigh from the variant picker (Ctrl+T) works — it just doesn't persist as the default.

Environment

• OpenCode: 1.4.3
• oh-my-openagent: 3.16.0
• Provider: OpenRouter
• Model: anthropic/claude-opus-4.6
• OS: WSL2 Ubuntu on Windows

Steps to Reproduce

1. Set variant: "xhigh" in oh-my-openagent.json:

{
  "agents": {
    "sisyphus": {
      "model": "openrouter/anthropic/claude-opus-4.6",
      "variant": "xhigh"
    }
  }
}

2. Run bunx oh-my-openagent doctor --verbose — confirms sisyphus: openrouter/anthropic/claude-opus-4.6 (xhigh) [capabilities: snapshot-backed]
3. Start opencode — status bar shows high, not xhigh
4. Open variant picker — xhigh IS available and selectable, but not the default
5. Selecting xhigh manually works fine

Root Cause

The plugin's model capability heuristic for claude-opus family only includes ["low", "medium", "high", "max"] — no xhigh. The variant picker shows the REASONING_LADDER (none, minimal, low, medium, high, xhigh) which does include xhigh. The downgradeWithinLadder function downgrades xhigh to high because it's not in the heuristic's allowed list.

However, patching the heuristic to include xhigh does not fix it either — opencode core applies its own validation after the plugin resolves the variant.

Expected Behavior

variant: "xhigh" in config should be respected as the default on startup, same as it works when selected manually from the picker.

Related

Same class of issue as #11307 (OpenRouter GPT-5.2-Codex missing xhigh variant).

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• subagent model variants are parsed but not applied at runtime in v1.4.0 #21632: subagent model variants are parsed but not applied at runtime in v1.4.0 — both report that a configured variant is visible in config/debug output but not honored at runtime/startup