OpenAI or Anthropic format: which one to use for Claude

from openai import OpenAI

client = OpenAI(base_url="https://www.ruapi.ai/v1", api_key="sk-...")

response = client.chat.completions.create(
    model="claude-sonnet-5-5",
    reasoning_effort="low",
    messages=[
        {"role": "system", "content": "You are a senior Python developer. Keep answers short."},
        {"role": "user", "content": "How do I reverse a list?"},
    ],
)
message = response.choices[0].message
print(getattr(message, "reasoning_content", None))  # thinking text
print(message.content)  # answer

import anthropic

client = anthropic.Anthropic(base_url="https://www.ruapi.ai", api_key="sk-...")

response = client.messages.create(
    model="claude-sonnet-5-5",
    max_tokens=2048,
    thinking={"type": "adaptive", "display": "summarized"},
    system="You are a senior Python developer. Keep answers short.",
    messages=[{"role": "user", "content": "How do I reverse a list?"}],
)
for block in response.content:
    if block.type == "thinking":
        print(block.thinking)  # thinking text
    elif block.type == "text":
        print(block.text)  # answer

curl https://www.ruapi.ai/v1/chat/completions \
  -H "Authorization: Bearer sk-..." \
  -H "Content-Type: application/json" \
  -d '{"model": "claude-sonnet-5-5", "messages": [{"role": "user", "content": "Hello"}]}'

curl https://www.ruapi.ai/v1/messages \
  -H "x-api-key: sk-..." \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{"model": "claude-sonnet-5-5", "max_tokens": 1024, "messages": [{"role": "user", "content": "Hello"}]}'