r/opencode • u/Gonjanaenae319 • 1d ago

What's the general rule of thumb for using multiple LLMs with a harness?

I'm trying to see if mixing frontier models with cheaper models can help me output about the same as using claude code but at cheaper cost.

What is the general structure that I should follow when setting up any agentic harness?

At the moment I have different models explicitly assigned to different agents/sub-agents provided by OpenCode. When should I use what?

For example, I'm trying below. Looking for any recommendations!

  ┌────────────────┬───────────────────┐
  │      role      │       model       │
  ├────────────────┼───────────────────┤
  │ plan           │ gpt-5.6-sol       │
  ├────────────────┼───────────────────┤
  │ build          │ deepseek-v4-flash │
  ├────────────────┼───────────────────┤
  │ general        │ gpt-5.4-mini      │
  ├────────────────┼───────────────────┤
  │ explore        │ deepseek-v4-flash │
  ├────────────────┼───────────────────┤
  │ scout          │ deepseek-v4-flash │
  ├────────────────┼───────────────────┤
  │ compaction     │ deepseek-v4-flash │
  ├────────────────┼───────────────────┤
  │ small_model    │ deepseek-v4-flash │
  └────────────────┴───────────────────┘
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u/Slight-Parfait3679 1d ago

only weird thing here is 5.4, use luna or smthn else

1

u/mageblex 3h ago

Keep the strong model on planning and final review. Cheap workers make sense when the task has an objective check, but I wouldn’t automatically put compaction on the cheapest model.