hermes - 💡(How to fix) Fix fix(gemini): systemInstruction missing required role field causes HTTP 500 on Gemma models

Bug

The Gemini native adapter (hermes/providers/gemini_native_adapter.py) constructs the systemInstruction field without the required "role": "system" key. This causes the Gemini API to return HTTP 500 on any request that includes a system prompt when using Gemma models (e.g. gemma-4-31b-it).

Root Cause

In gemini_native_adapter.py line ~326, the system instruction is built as:

system_instruction = {"parts": [{"text": joined_system}]}

The Gemini API requires the system instruction to include a role field:

system_instruction = {"role": "system", "parts": [{"text": joined_system}]}

Without this field, Gemma models consistently return 500 Internal Server Error. Other models (Gemini 2.5 Pro/Flash) appear to be more lenient and tolerate the missing field, which is why this went undetected.

Fix

Add "role": "system" to the systemInstruction dict. One-line change.

Verification

Tested with direct API calls:

• Without role: HTTP 500 on Gemma 4
• With role: HTTP 200, valid response