The trick: Announced Not Shipped

Reflection calls Beam a 501B open-weight model.

Its own post says the weights come later this month.

Issue 366 October 20269 receipts3 min

Reflection introduces Beam as its first open-weight model, 501 billion total parameters with 23 billion active, competitive with GLM 5.2 on coding and agentic tasks.

Before you read on. Your call?

The same post says Beam is undergoing final red-teaming and that the weights, technical report and model card will be released later this month.

The twist

Hacker News commenters flagged an open model that is not yet open, and Turing Post reported in March that the model at the center of Reflection's pitch had not been released publicly.

501 billiontotal parameters in Beam

23 billionactive parameters in Beam

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The trick has a name

We call it Announced Not Shipped: claimed, never released. You'll see it again. Learn to spot it →

Say this in tomorrow's meeting“Reflection announced Beam as a 501B open-weight model, but the weights, model card and technical report are promised for later this month.”

Receipts

Supports reflection.ai: We are introducing Beam, Reflection’s first open-weight model.
Supports reflection.ai: Beam is a sparse Mixture-of-Experts model with 501 billion total parameters, 23 billion active
Context reflection.ai: Beam is undergoing final red-teaming and evaluations.
Context reflection.ai: We will release the weights, technical report, model card, and developer artifacts later this month.
Supports reflection.ai: competitive with larger open models like GLM 5.2 and approaching Qwen 3.8-Max on coding and agentic tasks
Context reflection.ai: Where frontier open models like Kimi K3 remain ahead on raw capability, Beam's advantage is efficiency at inference time.
Refutes news.ycombinator.com: Open model that is not yet open or widely accessible via API.
Refutes news.ycombinator.com: says open but no weights. Feels like a bid to get a buyout before the weights go public.
Context web.archive.org: the frontier open-weight model at the center of its pitch still has not been released publicly

Open the Receipts Pack → What each source proves, every figure traced, and what would change our verdict.