A practical walkthrough for the original GPT-5.0 API release (pinned snapshot gpt-5-2025-08-07) using OpenAI's Responses API. Covers setting up an API key, sending a first request, and building a support triage workflow that returns strict JSON via a schema. Also explains how to tune reasoning.effort and text.verbosity, common mistakes when mixing Responses API and Chat Completions fields, and when full GPT-5.0 is worth the cost over lighter models.
Table of contents
What this GPT-5.0 guide coversGet your API key readySend your first GPT-5.0 requestBuild something useful: support triageReturn strict JSON with a schemaWhy this JSON pattern works wellTune reasoning effort and verbosity on purposeCommon mistakes that break GPT-5.0 requestsWhen full GPT-5.0 is worth usingConclusion3 Impressions