# X_AI_MODEL_UNRESOLVED

## Means

a model call named no model

## Typical cause

neither the declaration, its prompt, nor providerGateway({ defaultModel }) named one — the framework chooses no model for an app

## Fix

`llm({ ..., model: modelId })` — or model: modelId in its definePrompt, or providerGateway({ ..., defaultModel: modelId }); register the id with registerModel

[MCP and AI](/error-codes#mcp-and-ai)