The OpenAI Agents SDK (openai-agents) uses the OpenAI Python SDK under the hood, which uses httpx for HTTP transport. Agent tool calls that reach external services produce detectable TLS fingerprints.
| Component | User-Agent Pattern | JA4 Base |
|---|---|---|
| OpenAI SDK direct | OpenAI/Python 1.x.x | t13d3514h2_bfa337485184_* |
| Agents SDK | OpenAI/Python 1.x.x openai-agents/0.1.x | t13d3514h2_bfa337485184_* |
| GPTBot crawler | GPTBot/1.3 | t13d1011h2_61a7ad8aa9b6_* |
| ChatGPT-User | ChatGPT-User | t13d1011h2_61a7ad8aa9b6_* |
GPTBot and ChatGPT-User share the same JA4 cipher hash (61a7ad8aa9b6) with only 10 cipher suites — this is NOT vanilla Go net/http (which has 13 ciphers, hash f57a46bbacb6). OpenAI uses a customised TLS configuration or shared proxy infrastructure.