Opus without 1M context window not available in model list for subscriptions that don't include 1M

[michaelfsp]

Problem

Since v0.22, the only Opus model available in the model picker is the 1M context window variant (claude-opus-4-6-1m). For
users whose Claude subscription includes Opus but not the 1M context window tier, this means Opus is effectively
unusable — selecting it results in an error since the subscription doesn't cover the 1M variant.

In v0.21, the regular Opus model (without the 1M context window) was available and worked correctly with these
subscriptions.

Expected behavior

The available models list should include the standard Opus model (e.g., claude-opus-4-6) alongside the 1M variant, so
users whose subscriptions include regular Opus but not 1M can continue using it.

Steps to reproduce

1. Have a Claude Pro subscription
2. Install claude-agent-acp v0.22+
3. Open the model picker — only "Opus [1M]" is listed
4. Selecting it fails because the subscription doesn't cover the 1M variant (API Rate limit error message)

Workaround

Staying on v0.21 where the standard Opus model is available.

Environment

• claude-agent-acp: 0.22.x
• Claude Code CLI: 2.1.81
• Client: codecompanion.nvim

[josevalim]

I believe it passes everything that the Claude Agent SDK returns. If you are not seeing the regular one, is because the SDK is not exposing it.