OpenAI Euphony: A Browser-Based Viewer for Harmony Conversations and Codex CLI Sessions OpenAI just shipped Euphony — an Apache 2.0 open source web app for inspecting two specific formats that have been a pain to read with a text editor: Harmony conversations — the structural wire format gpt-oss models are trained on Codex CLI sessions — the rollout-*.jsonl files auto-created by Codex CLI Th