OpenCode failed with ‘ProviderModelNotFoundError.’ The model ID existed—just not spelled the way my config spelled it.

What Happened

ProviderModelNotFoundError when starting OpenCode. The oh-my-opencode.json config referenced model IDs that don’t exist in the provider definitions.

The Error

ProviderModelNotFoundError
providerID: "google"
modelID: "gemini-3-flash"
suggestions: ["gemini-3-flash-preview", "antigravity-gemini-3-flash"]

Investigation

1. Error showed suggestions for valid model names
2. Searched config files for the invalid model ID
3. Found references in ~/.config/opencode/oh-my-opencode.json:
   • Line 19: multimodal-looker agent
   • Line 39: visual-engineering category
   • Line 46: artistry category
   • Line 60: writing category

Resolution

Changed all occurrences to use valid model IDs:

// Before (invalid)
"model": "google/gemini-3-flash"
"model": "google/gemini-3-pro"

// After (valid - using antigravity provider)
"model": "google/antigravity-gemini-3-flash"
"model": "google/antigravity-gemini-3-pro"

Lesson

Model IDs in oh-my-opencode.json must exactly match the model IDs defined in opencode.json provider config. The error’s suggestions field shows valid alternatives - use those exact strings.