Reasoning · backend

Use Claude 3.5 Sonnet (Thinking) with Flask

Updated 2026-05-21 · By XALEN

1. Install

pip install xalen flask

2. Code

from flask import Flask, request, jsonify
from xalen import XALEN

app = Flask(__name__)
client = XALEN(api_key="xln_test_YOUR_KEY")

@app.route("/chat", methods=["POST"])
def chat():
    data = request.json
    response = client.chat.completions.create(
        model="claude-3-5-sonnet-thinking",
        messages=data["messages"]
    )
    return jsonify({"reply": response.choices[0].message.content})

if __name__ == "__main__":
    app.run()

Claude 3.5 Sonnet (Thinking) with Other Frameworks

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Last updated: 2026-05-21