Altimor reported on 2026-04-06 that, for the first time, an open-source model…

Brief

Altimor reported on 2026-04-06 that, for the first time, an open-source model outperformed Sonnet 4.6 on their internal evaluations, pointing to Arcee.ai's new Trinity-Large-Thinking. Arcee.ai released Trinity-Large-Thinking on the Arcee API with open weights on Hugging Face under Apache 2.0, targeting developers and enterprises for inspection, post-training, hosting, distillation and ownership; "vibe testing" now begins.

title: @Altimor: Okay this one seems real. First time ever an OSS model beats Sonnet 4.6(!!) on our evals. Now begins...
author: @Altimor
contenttype: tweet
publication: Twitter/X
published: 2026-04-06T17:02:38+00:00
sourceurl: https://x.com/Altimor/status/2041199915943215163

word_count: 67

Okay this one seems real. First time ever an OSS model beats Sonnet 4.6(!!) on our evals. Now begins vibe testing, but this is promising.

Arcee.ai (@arcee_ai)

Today we're releasing Trinity-Large-Thinking.

Available now on the Arcee API, with open weights on Hugging Face under Apache 2.0.

We built it for developers and enterprises that want models they can inspect, post-train, host, distill, and own.

Video

— https://nitter.net/arcee_ai/status/2039369121591120030#m