[BUG] settings.json "model" key ignored at session startup

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

~/.claude/settings.json has "model": "opus" as a top-level key, but Claude Code v2.1.50 ignores it at session startup and defaults to Sonnet 4.6 (the Claude Max subscription tier default).

The banner on launch shows:

Sonnet 4.6 · Claude Max

The --model opus CLI flag works correctly — launching with claude --model opus shows Opus in the banner. So the model override mechanism works, but the settings.json "model" key is not being read during init.

Tested across two consecutive fresh sessions — same behavior both times. No project-level settings.local.json overriding it.

What Should Happen?

When "model": "opus" is set in ~/.claude/settings.json, Claude Code should launch with Opus as the active model. The startup banner should show Opus 4.6 · Claude Max instead of Sonnet 4.6 · Claude Max.

Error Messages/Logs

No error message — Claude Code launches silently with the wrong model.

Terminal session showing the bug in real time:


    ✻
    |
   ▟█▙     Claude Code v2.1.50
 ▐▛███▜▌   Sonnet 4.6 · Claude Max
▝▜█████▛▘  ~/Documents/NS_Nascent
  ▘▘ ▝▝

❯ pls confirm the model in settings.json

⏺ Read 1 file (ctrl+o to expand)

⏺ Line 72: "model": "opus" — set to Opus.

  Per the environment note at the top of this session, CC is running on claude-sonnet-4-6 though.
   The model key in settings.json sets the model for future sessions — it takes effect when
  Claude Code starts, not mid-session.

❯ so if i close and reopen claude, it'll be Opus, right?

⏺ Yes — the "model": "opus" in settings.json will load Opus 4.6 (claude-opus-4-6) on the next
  session start.

❯ ok close this session and reopen

⏺ Can't close the session from within it — that's a user action. Just type /exit or close the
  terminal window, then reopen Claude Code.

❯ /exit
  ⎿  Goodbye!

─────────────────────────────────────────────────────────────────────────────────────────────────
❯
─────────────────────────────────────────────────────────────────────────────────────────────────
  ⏵⏵ accept edits on (shift+tab to cycle)

Resume this session with:
claude --resume 12ce908a-dd00-4879-b0be-541b863cedf9
MikeBookAir NS_Nascent % claude

    ✻
    |
   ▟█▙     Claude Code v2.1.50
 ▐▛███▜▌   Sonnet 4.6 · Claude Max
▝▜█████▛▘  ~/Documents/NS_Nascent
  ▘▘ ▝▝

❯ pls confirm the model in settings.json

⏺ Read 1 file (ctrl+o to expand)

⏺ The model is set to "opus" (line 72).

❯ /exit
  ⎿  Goodbye!

─────────────────────────────────────────────────────────────────────────────────────────────────
❯
─────────────────────────────────────────────────────────────────────────────────────────────────
  ⏵⏵ accept edits on (shift+tab to cycle)

Resume this session with:
claude --resume 6a1b1006-56c1-40de-9024-ebc700b8722c
MikeBookAir NS_Nascent % claude --model opus

    ✻
    |
   ▟█▙     Claude Code v2.1.50
 ▐▛███▜▌   Opus 4.6 · Claude Max
▝▜█████▛▘  ~/Documents/NS_Nascent
  ▘▘ ▝▝

❯ hooray! when i use the command line you use the opus model like i asked :)

  pls confirm the model in settings.json

⏺ Read 1 file (ctrl+o to expand)

⏺ Confirmed — line 72: "model": "opus". That's what's driving the Opus 4.6 model selection for
  all CC sessions.

❯ /exit
  ⎿  Catch you later!

─────────────────────────────────────────────────────────────────────────────────────────────────
❯
─────────────────────────────────────────────────────────────────────────────────────────────────
  ⏵⏵ accept edits on (shift+tab to cycle)

Resume this session with:
claude --resume c0dcf3e5-cd0e-463d-ba04-c0c4428a523c
MikeBookAir NS_Nascent % claude

    ✻
    |
   ▟█▙     Claude Code v2.1.50
 ▐▛███▜▌   Sonnet 4.6 · Claude Max
▝▜█████▛▘  ~/Documents/NS_Nascent
  ▘▘ ▝▝

❯ womp womp :(
  i didn't set the --model flag so you're back to sonnet.

  pls confirm model in settings.json

⏺ Read 1 file (ctrl+o to expand)

⏺ "model": "opus" is set at line 72. The session is running on Sonnet 4.6 though — that flag only
   takes effect when CC is launched fresh. Mike must have started this session without it picking
   up the config, or the --model flag at launch overrides it.

  To confirm: settings.json has the right value. The model CC runs in a session is locked at
  launch time — changing the file mid-session won't switch it. Mike would need to restart CC to
  get Opus.

❯ /exit
  ⎿  See ya!

─────────────────────────────────────────────────────────────────────────────────────────────────
❯
─────────────────────────────────────────────────────────────────────────────────────────────────
  ⏵⏵ accept edits on (shift+tab to cycle)

Resume this session with:
claude --resume f6c52bfd-8b79-4272-bb2e-b72f03fd6013
MikeBookAir NS_Nascent %

Steps to Reproduce

1. Add "model": "opus" as a top-level key in ~/.claude/settings.json
2. 2. Quit and relaunch Claude Code (claude)
3. 3. Observe the startup banner — it shows Sonnet 4.6 · Claude Max instead of Opus
4. 4. Confirm with /model — Sonnet is active, not Opus
5. 5. For comparison: claude --model opus correctly launches with Opus

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.50 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Subscription: Claude Max

Relevant section of ~/.claude/settings.json:

{
  "permissions": {
    "defaultMode": "acceptEdits",
    ...
  },
  "model": "opus"
}

The "model" key is top-level (not nested inside permissions). The --model opus CLI flag works, which confirms the model override mechanism itself is functional — the issue is specifically that settings.json isn't being read for this key at init.

Workaround: alias claude='claude --model opus' in ~/.zshrc.