AI digest: 2026-10-13

Highlights

Meta Muse Wonder: Meta's strongest agent models so far, with cross-session "Active Memory". Like Muse Spark, they are API-only, with no open weights.
Hidden capabilities in model weights: a paper shows that capabilities can be hidden behind a cryptographic trigger so that capability evals provably cannot find them.
Claude open questions answered: Haiku 5.5 can disable thinking at effort high or below; Haiku 4.5 has no retirement notice yet (gap fill).

Muse Wonder: Meta's API-only agent models with Active Memory and Active Focus; no scores or prices yet.
Troubleshooting thinking (Claude API docs): per-model table of thinking modes, defaults, and rejected settings (gap fill).
Model deprecations (Claude API docs): lifecycle status and retirement dates; Sonnet 4.5 retires 2026-11-30 (gap fill).

AI Models Can Provably Hide Arbitrary Capabilities: encrypted backdoor circuits that resist all tested elicitation methods.
Thinking Inertia: "don't think" prompts do not reliably stop visible reasoning.

models/claude: thinking-disable rules per model; Haiku 4.5 and Sonnet 4.5 retirement status; two open questions resolved (gap filled).
models/open-weight: Muse Wonder confirms Meta's closed, API-first line.
agents/memory: Muse Wonder's Active Memory as a model-level feature.
fundamentals/reasoning-models: Thinking Inertia guidance; Claude thinking controls by model.
practices/evals: limits of capability elicitation.
practices/security: hidden model capabilities as a supply-chain risk.