[Bug]: Switching Sisyphus model before session starts does not take effect

[812152511]

Prerequisites

• I have searched existing issues to avoid duplicates
• I am using the latest version of oh-my-opencode
• I have read the documentation

Bug Description

When starting opencode, before the conversation starts, the gork model is selected, but it does not take effect after executing the conversation. The default configuration is still used, and the conversation is interrupted. After selecting the grok model again, it can take effect

Steps to Reproduce

selected grok:

Still using the default model configuration:

Interrupt and reselect the model:

effective:

Expected Behavior

After starting the conversation, Sisyphus should directly use the Grok model

Actual Behavior

The default configuration model used by Sisyphus

Doctor Output

Installation
────────────────────────────────────────
  ✓ OpenCode Installation → 1.1.34
  ✓ Plugin Registration → Registered

Configuration
────────────────────────────────────────
  ✓ Configuration Validity → Valid JSON config

Authentication
────────────────────────────────────────
  ✓ Anthropic (Claude) Auth → Auth plugin available
  ✓ OpenAI (ChatGPT) Auth → Auth plugin available
  ✓ Google (Gemini) Auth → Auth plugin available

Dependencies
────────────────────────────────────────
  ⚠ AST-Grep CLI → Not installed (optional)
  ⚠ AST-Grep NAPI → Not installed (optional)
  ⚠ Comment Checker → Not installed (optional)

Tools & Servers
────────────────────────────────────────
  ⚠ GitHub CLI → Not installed (optional)
  ✓ LSP Servers → 3/4 servers available
  ✓ Built-in MCP Servers → 2 built-in servers enabled
  ○ User MCP Configuration → No user MCP configuration found

Updates
────────────────────────────────────────
  ✓ Version Status → Up to date (2.14.0)

Summary
────────────────────────────────────────

  9 passed, 0 failed, 4 warnings, 1 skipped
  Total: 14 checks in 1389ms

⚠ All systems operational with warnings.

Error Logs

Configuration

Additional Context

No response

Operating System

macOS

OpenCode Version

1.1.34

[justsisyphus]

Analysis: Model Override Not Applied on Session Start

Root Cause Identified

The bug occurs in the agent initialization flow when a session starts. Here's the issue:

Location: src/plugin-handlers/config-handler.ts:136-146

When createBuiltinAgents() is called, it receives:

• Parameter 2: pluginConfig.agents (the agent overrides from config)
• Parameter 4: config.model (the system default model)

The Problem: The agent overrides are passed correctly, BUT the timing of when they're applied vs. when the session initializes creates a race condition or initialization order issue.

Code Flow Analysis

1. Config Loading (config-handler.ts:136):

   • createBuiltinAgents() is called with pluginConfig.agents (user's model override)
   • This should apply the Grok model override to Sisyphus

2. Agent Creation (agents/utils.ts:240-276):

   • sisyphusOverride = agentOverrides["sisyphus"]
   • Model resolution happens: resolveModelWithFallback({ userModel: sisyphusOverride?.model, ... })
   • Config is merged: mergeAgentConfig(sisyphusConfig, sisyphusOverride)

3. Session Start:

   • The agent config should be used, but it appears the override isn't being persisted or re-read when the session actually starts

Likely Root Cause

The agent overrides are applied during plugin initialization, but when a new session starts, the agent configuration might be:

• Re-initialized from the default config without re-reading the overrides
• Cached before the user changes the model selection
• Not properly passed to the session context

Reproduction Pattern

1. User selects Grok model in UI (before session starts)
2. Session initializes → uses default model instead of Grok
3. User selects Grok again → now it works

This suggests the override is being set in config but not being read during the initial session setup.

Suggested Investigation Areas

1. Session initialization hook - Check if agent config is re-fetched when session starts
2. Config caching - Verify that model overrides aren't cached before user selection
3. Agent context propagation - Ensure overrides flow from config → agent creation → session context

Next Steps

Need to trace:

• Where session agent config is determined
• Whether createBuiltinAgents() is called once (plugin init) or per-session
• If there's a separate code path for session-specific agent config

This is a valid bug - the model override should take effect immediately on session start.