Copy-and-adapt, not import-and-share
Each variant's routes/chat.py is a deliberate copy of the Claude route. They share the pattern (JSONL ground truth, SQLite store, ChromaDB embedding, healing) but own their own code. No shared helper extraction across variants.
Why no shared helper
Shared helpers in this layer would force every variant through a lowest-common-denominator interface — exactly what Rule 1 forbids. Each variant evolves independently. If three variants discover they need the same change, the third is the one that proves the pattern is worth extracting. Until then: copy.
Tool bridge is brain-agnostic
The one place sharing is correct: tool_bridge.py. Local Read/Write/Edit/Bash execution is the same regardless of which brain requested it. The variant-specific part is schema format conversion (OpenAI for Codex/Ollama, function_declarations for Gemini, wrapping for Ollama).