The Crossover · Issue Nº 13

OpenAI overtakes Anthropic in developer conversation as GPT-6 Astra lands

GPT-6 Astra's launch pushed the OpenAI family past Anthropic in developer conversation for the first time, even as Python SDK downloads fell for both.

March – September 2026 (September partial, ~7 days) · Published 2026-09-09

The brief

01The OpenAI family rose from 22.1% of AI-model developer conversation in March to 47.9% in partial September, while the Anthropic family fell from 70.1% to 42.2%. The 48-point gap in March became a 5.7-point lead for OpenAI.
02The weekly crossover happened in the week of Aug 31: OpenAI family recorded 248 mentions versus Anthropic's 223. Every prior week in the 12-week window, Anthropic led.
03GPT-6 Astra launched Sept 3 (258 peak score), but the conversation surge drew on multiple threads: the ChatGPT/Codex LibreOffice bundling discovery (473), ChatGPT Work (338 and 235), the simultaneous OpenAI/Anthropic outage (397 and 168), and an ARC-AGI-3 benchmark (232).
04On hn_top during the turning week, OpenAI family stories (29) nearly doubled Anthropic family stories (15). On hn_new the split was roughly even (303 vs 314). The crossover is concentrated at the high-engagement tier.
05OpenAI's npm SDK edged past Anthropic's for the first time: 39.0M weekly downloads vs 38.0M. Both PyPI SDKs declined sharply over 28 days (OpenAI −42.6%, Anthropic −37.8%). Codex npm installs (20.4M) are within 5% of Claude Code (21.5M).

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