[Bug] Opus model defaults to 1M context window instead of native limit

Bug Description
Claude Code is now defaulting to a 1M context window when using Opus, which started after a recent update. Running /model opus doesn’t resolve it. The only workaround I’ve found is setting CLAUDE_CODE_DISABLE_1M_CONTEXT=1, which feels unnecessary and inconvenient.

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.1.118
• Feedback ID: 673ac133-9756-46ef-96de-9bd670cff6fa

Errors

[{"error":"Error: 429 {\"type\":\"error\",\"error\":{\"type\":\"rate_limit_error\",\"message\":\"Extra usage is required for long context requests.\"},\"request_id\":\"req_011CahxpoZ63Mx6mHTu1a1jg\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:55186)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:50:4943)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-04T17:58:56.978Z"}]