Anthropic releases Claude Opus 4.7

The single strangest thing about Claude Opus 4.7 is what Anthropic chose not to ship. In the same materials that call 4.7 its most powerful generally available model, the company acknowledges an even more capable system — Claude Mythos Preview — that remains locked behind Project Glasswing, distributed to only about 40 vetted enterprise and government partners. The stated reason is safety: Mythos can autonomously discover and exploit zero-day vulnerabilities, a capability Anthropic is not willing to put on a public rate card.

That framing reshapes how to read 4.7. It is not simply the next iteration on a linear curve; it is a deliberately constrained sibling of a model the company believes is too dangerous to release broadly. Anthropic says it reduced cyber capabilities during training and added automatic detection and blocking of high-risk cybersecurity requests, pairing that with a new Cyber Verification Program for researchers who need access to the sharper edges. The result is a product that is explicitly less than what Anthropic could ship — a posture that will either look prudent or self-sabotaging depending on whether rival labs feel bound by the same line.

Opus 4.7's headline price is a non-event: $5 per million input tokens and $25 per million output tokens, exactly matching Opus 4.6. The quieter change is underneath. Anthropic shipped a new tokenizer that processes text more efficiently on the model side but produces roughly 1.0 to 1.35 times more tokens per input than the previous one, depending on content type. The rate card is flat; the meter runs faster.

For casual users this is invisible. For teams running high-volume agentic pipelines, it is a stealth price hike of up to 35% that will not show up in any press release. It also complicates apples-to-apples cost comparisons with Opus 4.6, GPT-5.4, and Gemini 3.1 Pro, because the denominator has quietly changed. The dynamic has already become a talking point in power-user communities, where tokenizer bloat sits alongside other concerns about whether the upgrade is as economical as the unchanged price tag suggests.

The early-partner testimonials are strong and specific. Cursor's Michael Truell reports CursorBench climbing from 58% on Opus 4.6 to 70% on 4.7. Rakuten's Yusuke Kaji says the model resolves three times more production tasks than its predecessor. Box's Yashodha Bhavnani cites a 56% reduction in model calls and a 50% reduction in tool calls on internal workflows. XBOW's Oege de Moor describes an internal visual-acuity benchmark jumping from 54.5% to 98.5%. These are the kinds of numbers that close enterprise deals.

The power-user reception has been sharply different. The most-engaged follow-up threads on r/ClaudeAI and r/ClaudeCode frame 4.7 as a regression rather than an upgrade, describing ignored configured preferences, ignored citation requirements, fabricated search behavior, unsolicited editorial refusals, and unusable per-session limits on Claude Max. Community concerns cluster around four items: tokenizer-driven effective price increases, stricter instruction-following that breaks prompts tuned for earlier Opus versions, the removal of the Extended Thinking toggle in favor of a non-controllable Adaptive Thinking behavior, and a reported drop on long-context MRCR v2 at 1M tokens from 78.3% to 32.2%. The split suggests 4.7 is optimized for the agentic, tool-heavy workloads enterprise partners stress-tested, while individual power users who had hand-tuned earlier Opus workflows are finding the new defaults disruptive.

On benchmarks Anthropic controls the narrative for, the numbers are unambiguous. SWE-bench Pro rises from 53.4% on Opus 4.6 to 64.3% on 4.7. SWE-bench Verified climbs from 80.8% to 87.6%, ahead of Gemini 3.1 Pro at 80.6%. Terminal-Bench 2.0 moves from 65.4% to 69.4%. MCP-Atlas tool use hits 77.3%, described as best-in-class. OSWorld-Verified computer use rises from 72.7% to 78.0%. CharXiv visual reasoning without tools jumps from 69.1% to 82.1%, and GPQA Diamond reaches 94.2%.

But the lead is narrower than the individual line items suggest. VentureBeat's Carl Franzen notes that on directly comparable benchmarks Opus 4.7 only leads GPT-5.4 seven-to-four, and BrowseComp has actually dropped 4.4 points from 83.7% to 79.3%, making 4.7 slightly weaker for research-heavy web browsing. Anthropic also flags a modestly weaker posture on harm-reduction advice about controlled substances versus 4.6. The shape of this release, in other words, is a focused push on coding, tool use, agentic computer use, and vision — paid for with trade-offs elsewhere and with a top-of-leaderboard position that rivals can plausibly reclaim within a single release cycle.