GoKawiilMigrating to HTTPX2
The OpenAI Python SDK now uses HTTPX2 for its synchronous and asynchronous HTTP clients. HTTPX2 is installed automatically with openai ; the previous httpx package is not. This guide explains what changes for applications that interact with the SDK's HTTP layer.
If you use the SDK's default HTTP client
If you construct an OpenAI or AsyncOpenAI client without providing http_client , your existing API calls, parsed response models, streaming APIs, authentication, retries, and numeric timeouts continue to work:
from openai import OpenAI client = OpenAI ( timeout = 30.0 ) response = client . responses . create ( model = "gpt-5.5" , input = "Hello" )
No HTTPX2 extra or separate installation is required:
pip install openai
If your application imported httpx only because an earlier SDK installed it transitively, add your own httpx dependency or migrate those imports to httpx2 . Installing the SDK no longer installs httpx for you.
TLS certificates and trust stores
HTTPX2 changes the default TLS trust store, including for applications that use the SDK's default HTTP client. HTTPX previously verified certificates against the CA bundle provided by certifi . HTTPX2 instead uses the operating-system trust store, and the SDK no longer installs certifi .
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