Build variant in config gets ignored by TUI due persisted per-model variant state

[dhruvkej9]

Description

Hey team, I found a variant precedence issue that is pretty confusing in day-to-day usage.

I set agent.build.variant in ~/.config/opencode/opencode.json to medium, but when I start opencode in TUI it still opens with high for openai/gpt-5.3-codex.

This happens because TUI restores variant from persisted state (~/.local/state/opencode/model.json) and submits that explicit variant, so config fallback never gets used.

I can reproduce this reliably and also confirmed by checking stored message data in opencode.db.

Expected behavior (for a new session):

• If no CLI --variant is passed, config agent.build.variant should be respected.
• Persisted UI variant should not silently override config unless there is an explicit “remember last variant” mode.

Actual behavior:

• Persisted per-model variant wins (ex: high) even when config says medium.
• opencode -s <session> also restores last message variant and keeps forcing that value.

This makes config changes feel broken because they don’t take effect in fresh TUI usage.

Plugins

opencode-antigravity-auth@latest, @mohak34/opencode-notifier@latest

OpenCode version

1.2.4

Steps to reproduce

1. Set agent.build.variant to medium in ~/.config/opencode/opencode.json
2. Ensure ~/.local/state/opencode/model.json has variant["openai/gpt-5.3-codex"] = "high"
3. Start TUI with opencode
4. Observe header shows Build ... high
5. Send a prompt and inspect opencode.db message data: variant is stored as high

Also with session resume:
6. Run opencode -s <existing-session-id> where last message variant was high
7. Observe resumed session keeps high even after config changed to medium

Relevant code paths:

• packages/opencode/src/cli/cmd/tui/context/local.tsx (loads/saves model.json variant map)
• packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx (submits explicit variant)
• packages/opencode/src/session/prompt.ts (uses input.variant first, config variant only as fallback)

Screenshot and/or share link

No share link; validated with runtime behavior + DB inspection (opencode.db) and source reading.

Operating System

WSL2 (Ubuntu 24.04)

Terminal

Windows Terminal

[github-actions]

This issue might be a duplicate of or related to #13456: TUI model selection gets overwritten by agent default model.

Both issues involve state persisted in ~/.local/state/opencode/model.json inappropriately overriding configuration settings:

• [Bug] TUI model selection gets overwritten by agent default model #13456 focuses on model selection being overwritten by agent defaults
• Build variant in config gets ignored by TUI due persisted per-model variant state #13718 focuses on build variant being overwritten by persisted per-model state

While they affect different aspects (model vs variant), they likely share the same root cause regarding state precedence and could potentially be fixed together.

[dhruvkej9]

@rekram1-node Can you check this? It is on the latest version, I just tried many times and it is 100% reproducible

[demian85]

Variants are not respected in both TUI and desktop, even though they are configured in opencode.json:

  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "openai": {
      "models": {
        "gpt-5.3-codex": {
          "variants": {
            "low": {
              "reasoningEffort": "low",
              "reasoningSummary": "auto",
              "textVerbosity": "medium",
              "disabled": false
            },
            "medium": {
              "reasoningEffort": "medium",
              "reasoningSummary": "auto",
              "textVerbosity": "medium",
              "disabled": false
            },
            "high": {
              "reasoningEffort": "high",
              "reasoningSummary": "auto",
              "textVerbosity": "medium",
              "disabled": false
            }
          }
        }
      }
    }
  },
  "agent": {
    "build": {
      "model": "openai/gpt-5.3-codex",
      "variant": "medium"
    },
    "plan": {
      "model": "openai/gpt-5.3-codex",
      "variant": "high"
    }
  }
}

When changing agents, the default variant is not used.

[github-actions]

To stay organized issues are automatically closed after 60 days of no activity. If the issue is still relevant please open a new one.

[dhruvkej9]

@rekram1-node
The issue is clear and shouldn't be closed without any feedback as this is a bug issue not a feature so it can't be closed as "not planned"

[tarurar]

Completely agree. There is related one #16034