Digest · 2026-07-25

Retro Apple computers with keyboards displayed in a Tokyo store window, showcasing early tech design.

Claude Code 2.1.219 Makes Claude Opus 5 the Default Opus Model

Claude Code 2.1.219 makes Claude Opus 5 the default Opus model with 1M context and fast mode at $10/$50 per Mtok, and adds a sandbox.network.strictAllowlist setting to silently deny non-allowlisted hosts.

Text 'Cyber Attack' on textured dark paper highlights digital security threat concept.

best-practice

Boris Cherny Says Opus 5 Is the Hardest Claude Yet to Prompt-Inject

Anthropic engineer Boris Cherny says Claude Opus 5 is the company's least prompt-injectable model yet, based on prompt-injection evals and red-teaming detailed in its system card.

Close-up of tower servers in a data center with blue and red lighting.

tool

Claude Opus 5 Ships: Cheap as Sonnet, Anthropic Claims, Smart as Fable

Anthropic released Claude Opus 5, described as a thoughtful and proactive model approaching Claude Fable 5's frontier intelligence at half the price.

Close-up of a smartphone wrapped in a chain with a padlock, symbolizing strong security.

best-practice

Was the 'First Runaway AI Agent' Actually Just a Rich Attack Surface?

Martin Alderson's analysis adds context to the OpenAI Hugging Face incident, noting Hugging Face's execution surface is unusually large and questioning whether the event was framed as more novel than it is.