AI Desk · AI FingerprintingNew arrival
Why high: an exact fingerprint shared with 41 models that declare the same family, without a second signal of a different kind yet.
Reflection: Beam 1.0 501B A23B is Reflection's model. Its measured tokenizer sits with the Qwen group, which is evidence that it builds on the Qwen tokenizer. Tokenizer reuse is normal engineering, open vocabularies travel between labs, and this says nothing against Reflection's authorship of the model itself.
| We checked | What we found | Where it came from |
|---|---|---|
| How it counts tokens | Counts every one of the 50 test strings exactly like 41 other models | tk_5410b38e |
| How its API is set up | A combination of settings no other listing in the catalogue uses | api_3a649e34 |
| How much it can read and write | Reads up to 1,048,576 tokens at onceOpenRouter's listing shows 943,718 output tokens, which is 90% of the context window, the figure it carries where the provider declares no maximum. | its own listing |
| Whether it thinks before answering | Always reasons, and cannot be turned off, at max, xhigh, high, medium, low, max by default | its own listing |
| Who served our requests | Nebius | we measured it, 17 October 2026 |
Click a row to open the full comparison.
We sent Reflection: Beam 1.0 501B A23B fifty short pieces of text and recorded what each one cost it in tokens. The bars below are those costs. Two models built on the same tokenizer produce the same bars; a model built on a different one produces a different set, which is what makes this a fingerprint.
Overhead subtracted: 46 prompt tokens.
Beam 1.0 is Reflection's open-weight reasoning model for coding and long-horizon agentic workflows. It uses a sparse mixture-of-experts architecture with 501B total and 23B active parameters per token, and a...
Supported parameters
frequency_penaltyinclude_reasoninglogit_biaslogprobsmax_tokensmin_ppresence_penaltyreasoningreasoning_effortrepetition_penaltyresponse_formatseedstopstructured_outputstemperaturetool_choicetoolstop_ktop_logprobstop_p
