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ModelActiveProprietaryfamily · Claude

Claude Fable 5.1

Anthropicplatform.claude.com/docs/en/models/fable-5-1/ove

For demanding reasoning and long-horizon agentic work

quality80

Updated 42 min ago · first seen 11 Sept 2026

model_01M293V7EK3CVA2J99BHKR8PHG

Context
1M tokens
T1 · 1 h ago
Released
1 Sept 2026
T1 · 1 h ago
Knowledge cutoff
Jun 2026
T1 · 1 h ago

As of

Rewind the record: see this entity's attributes exactly as AI Atlas knew them on a given day.

Claim history · Input modalities

2 claims · 1 properties1 conflictingShow all properties

Input modalitiesmodalities_input2conflicting claims

Claim history for Input modalities
ValueValid from → toStatusSourceConfidenceExtractor
image, textcurrentconflictingOpenRouter public model & pricing listingT2mediumdeterministic
text, imagecurrentcurrentClaude Developer Platform docsT1conflicteddeterministic

Claims are temporal and append-only: a new observation closes the previous claim (valid_to) instead of overwriting it. Conflicting claims from different sources are kept side by side and flagged — never averaged. Methodology →