openai breaking changes

3.0.0

340 breaking changes, first published August 12, 2026.

• Behavior changed
  The SDK now uses HTTPX2 for its default clients, and installing openai no longer installs httpx. Code using custom HTTPX clients, transports, or configuration must move to HTTPX2 equivalents or install httpx explicitly. github.com
• Behavior changed
  With the default client, raw request, response, and transport exception objects are HTTPX2 types instead of HTTPX types. Code that inspects these objects must be updated. github.com
• Behavior changed
  Certificate verification now uses the OS trust store and certifi is no longer installed, which can break verification in some environments. Configure system CAs, SSL_CERT_FILE, SSL_CERT_DIR, or a custom ssl.SSLContext. github.com
• Behavior changed DefaultAsyncHttpxClient
  The existing name still works but builds HTTPX2 async clients. Prefer DefaultAsyncHttpx2Client to make the HTTP client family explicit. github.com
• Behavior changed DefaultHttpxClient
  The existing name still works but builds HTTPX2 clients. Prefer DefaultHttpx2Client to make the HTTP client family explicit. github.com
• Signature changed openai.APIConnectionError.__init__
  Was def __init__(self, *, message: str = 'Connection error.', request: httpx.Request) -> None; now def __init__(self, *, message: str = 'Connection error.', request: httpx2.Request) -> None. pypi.org
• Signature changed openai.APIError.__init__
  Was def __init__(self, message: str, request: httpx.Request, *, body: object | None) -> None; now def __init__(self, message: str, request: httpx2.Request, *, body: object | None) -> None. pypi.org
• Signature changed openai.APIError.request
  Was request: httpx.Request; now request: httpx2.Request. pypi.org
• Signature changed openai.APIResponseValidationError.__init__
  Was def __init__(self, response: httpx.Response, body: object | None, *, message: str | None = None) -> None; now def __init__(self, response: httpx2.Response, body: object | None, *, message: str | None = None) -> None. pypi.org
• Signature changed openai.APIResponseValidationError.response
  Was response: httpx.Response; now response: httpx2.Response. pypi.org

And 330 more in this version.

Check your code

These are the changes. To see which of them reach your code, scan a public repository, or have your coding agent call check_code with your manifest or lockfile over MCP. The API reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys.