WhichAI / Models / Claude Mythos 5.1

Claude Mythos 5.1

· verified October 14, 2026

public paid api in Generator reasoning agents

Provider

Statuspublic

AA Intelligence Indexnot measured yet

Released2026-09-01

Context windown/a

Modalitiesn/a

API price $/1M (in / out)n/a

Speedn/a

AccessReleased September 1, 2026 alongside Fable 5.1 · availability varies by plan

The score shown is a WhichAI estimate from adjacent benchmarks, not an official measurement.

In one line

Shipped the same day as Fable 5.1 and aimed at technical and scientific work (52.6% on Terminal-Bench Science at launch). No index score published yet, so the figure here is an unmeasured estimate and this entry never enters a ranking.

Coding90

Reasoning93

Writing86

Agents & tools92

Category scores (0-100) are WhichAI blended ratings: public category leaderboards plus editorial judgment. Guidance, not official measurements.

Alternatives worth a look

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Ministral 3 8B 2512 (Mistral AI) · AA 5.5API $0.15/$0.15 per 1M tokens on OpenRouter · open weights · listed December 2, 2025

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Artificial Analysis Intelligence Index, official scale (the number published on artificialanalysis.ai), relayed by OpenRouter and refreshed automatically: last read October 14, 2026. 209 models carry a current official measurement. A value marked ~ is converted from an earlier snapshot because no current measurement is published; an unmeasured model is never ranked. Context, price, modality and listing dates come from the public OpenRouter model list (refreshed automatically on the live site; static copy retrieved October 3, 2026) and vendor pages. Missing values are not published or not yet verified - shown as -. Sources are linked inside the app (the Ranking chapter and About > Methodology).