4.9.6 会话API无法传参system

[goactiongo]

curl  'http://xxxxx/api/v1/chat/completions' \
-H 'Authorization: Bearer fastgpt-xxxxxx8IJum' \
-H 'Content-Type: application/json' \
-d '{
    "stream": true,
    "customUid":"test",
    "messages": [
          {"role": "system", "content": "用英语 回答."},
          {"role": "user", "content": "你是谁!"}
    ]
}'