Claude Code Fable 5.1 context capped at ~200K due to version bug

zaziszaz · ghdev · 2026-09-02

User reports that on Claude Code 2.1.252, the claude-fable-5-1 model is restricted to a 200K token context window, far below the expected 1M, despite the version meeting Help Center requirements. The client marks the model as disabled but still serves it. Measurements show other models (Opus 5, Sonnet 5) on the same environment handle 800K+ tokens. The analysis suggests the binary lacks the model ID, causing a fallback to a hardcoded default limit.

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