{"version":"2.1.283","anchor":"opus-subagents-can-get-the-1m-context-variant","canonical_anchor":"default-opus-gets-the-1m-suffix-only-where-1m-context-is","heading":"Opus [1m] suffix and \"with 1M context\" label now depend on each model's 1M support","tier":"notice","area":"Subagents","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.283\/e\/opus-subagents-can-get-the-1m-context-variant","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.283","markdown":"### Opus [1m] suffix and \"with 1M context\" label now depend on each model's 1M support\n\nDefault Opus, Opus subagents and the picker label add 1M context only where a model's 1M window is opt-in, not native\n\n**Unclear.** It is not clear where this step is used, so when subagents actually get the 1M version is unsettled.\n\n**What**\n\nThe context window is how much text a model can consider at once. Some models have a 1M-token window built in (native). Others offer it only when asked for (opt-in), which Claude Code does by adding `[1m]` to the model name. Claude Code now tracks each model's 1M support as \"never\", \"native\" or \"optIn\" instead of a yes or no:\n\n- `CLAUDE_CODE_DISABLE_1M_CONTEXT` makes every model count as \"never\".\n\n- Default Opus: `[1m]` is added to the default Opus model only when its support is \"optIn\". Models with a native 1M window no longer get `[1m]`.\n\n- Picking opus: when the opus alias points to a model with opt-in 1M, choosing it now resolves to that model with `[1m]`. The option label also shows the resolved model id.\n\n- Subagents: an Opus-family subagent model gets `[1m]` when it lacks it and its 1M support is \"optIn\" on a first-party provider.\n\n- Model picker: the Opus description shows \"with 1M context\" based on the selected model's support being \"optIn\", instead of one global check. Opus counts as 1M-eligible unless its support is \"never\".\n\n**Why**\n\nThe model name shown for default Opus may change, and Opus subagents may now run with a larger context window, which can affect cost. The picker should stop claiming 1M context for Opus models that do not offer it.\n\n- Area: Subagents\n- Tier: You'll notice\n- Useful: 3\/5\n- Signal: 3\/5"}