[Bug] claude-opus-4-6 model not recognized despite API availability

[Deepak-Cognichip]

Bug Description
Here's the updated bug report with this evidence included:

---

Bug: /model claude-opus-4-6 returns "Model not found" despite the model being fully accessible via the API.

Steps to reproduce:

1. Open Claude Code v2.1.62
2. Type /model claude-opus-4-6
3. Error: Model 'Opus 4.6' not found

Expected: Model switches to claude-opus-4-6

Actual: Model not found error

Evidence — API works perfectly:

curl https://api.anthropic.com/v1/messages with model "claude-opus-4-6"
→ Response: {"model":"claude-opus-4-6","type":"message",...} ✅

• Direct API call with the same key returns a valid response from claude-opus-4-6
• Same API key accesses claude-opus-4-6 successfully via Cursor
• GET /v1/models lists claude-opus-4-6 as available for this key
• Other date-suffixed Opus models (e.g. claude-opus-4-20250514) work fine via /model

Root cause hypothesis: Claude Code's internal model validation/allowlist does not include claude-opus-4-6 (no date suffix), even though the API accepts it. The UI tooltip even prompts /model to try Opus 4.6, making this a direct contradiction in the product.

Environment:

• Claude Code v2.1.62
• macOS (Apple Silicon)
• API billing: standard tier

---

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.62
• Feedback ID: ea8c7f4d-fe01-4a88-8a38-7b05cd916d60

Additional Information

[Additional evidence — full API response confirming model works:

curl https://api.anthropic.com/v1/messages (with model "claude-opus-4-6")

Response:
{
  "model": "claude-opus-4-6",
  "id": "msg_01NyZ5c47XtTCHLH1MUBr3sX",
  "type": "message",
  "role": "assistant",
  "content": [{"type": "text", "text": "Pong! 🏓"}],
  "stop_reason": "max_tokens",
  "usage": {"input_tokens": 8, "output_tokens": 16, "service_tier": "standard"}
}

Also, /v1/models lists these as available for this key:
- claude-opus-4-6  ← not recognized by /model
- claude-opus-4-5-20251101
- claude-opus-4-1-20250805
- claude-opus-4-20250514]

[sstklen]

The /model command likely validates against a set of known model identifiers that doesn't include short aliases like claude-opus-4-6 — only the date-suffixed variants. This is despite the API accepting both forms, which creates the contradiction you noticed (the tooltip suggests trying "Opus 4.6" but /model claude-opus-4-6 rejects it).

Workaround: Use the full date-suffixed model name with /model:

/model claude-opus-4-20250514

You've already confirmed this version is available on your key, so it should work. The short alias just isn't mapped in Claude Code's model picker validation yet — the API is fine, it's the UI-side validation that needs updating.

[github-actions]

Closing for now — inactive for too long. Please open a new issue if this is still relevant.

[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.