Anthropic 发布 Claude Sonnet 5，定价不变但 token 消耗增加

In separate announcements, Sonnet 5 was released today, and Fable/Mythos 5 were approved to be released again after some work with the government. The primary discussion around Sonnet 5’s efficiency was a damper on the excitement, driven by tokenizer changes and 3-6x more turn taking in benchmarks:Our newest staff writer is reporting on the ground from AIE, and you can catch swyx and other keynote speakers on the stream today:AI News for 6/29/2026-6/30/2026. We checked 12 subreddits, 544 Twitters and no further Discords. AINews’ website lets you search all past issues. As a reminder, AINews is now a section of Latent Space. You can opt in/out of email frequencies!AI Twitter RecapAnthropic launched Claude Sonnet 5 as its new default mid-tier frontier model, with immediate rollout across Claude, Claude Code, API, and ecosystem partners.Anthropic officially announced Claude Sonnet 5 as “our most agentic Sonnet yet,” emphasizing planning, browser/terminal tool use, and autonomous execution that previously “required larger and more expensive models” (@claudeai)Anthropic’s developer account said Sonnet 5 offers top-tier coding and tool-use performance at Sonnet pricing, with a 1M-token context window, and is the new default in Claude Code for Pro users and available on the Claude Platform including API and Managed Agents (@ClaudeDevs)Anthropic kept the standard list price at $3/M input tokens and $15/M output tokens, but introduced a promotional rate of $2/M input and $10/M output through Aug. 31 / Sept. 1 depending on the post (@kimmonismus, @ClaudeDevs, @ArtificialAnlys)Sonnet 5 surfaced first through leaks and client-side sightings: leakers claimed knowledge cutoff January 2026, $2/$10 promo pricing, and a 1M-context variant before launch (@kimmonismus); users then reported it appearing in the model selector, Claude Code 2.1.197, Anthropic GitHub, and finally going live in accounts including Germany (@kimmonismus, @scaling01, @scaling01, @kimmonismus)Anthropic simultaneously expanded platform support around the launch: Claude Desktop on Linux (Ubuntu/Debian beta) with Claude Code/Cowork/chat on paid plans, though Computer Use was not included in that Linux release (@ClaudeDevs, @ClaudeDevs)Anthropic also shipped Managed Agents updates—streaming session deltas, per-session overrides, webhook events, reverse pagination, credential injection scoping, and an observability tab with token/tool metrics—making the release as much platform/integration story as raw model story (@ClaudeDevs, @ClaudeDevs)Launch timeline and pre-release narrativeThe launch was preceded by a large rumor cycle centered on Sonnet 5 + Fable 5.Earlier app-string sleuthing suggested Anthropic was preparing to put “Fable 5” behind a separate usage-credit system billed outside existing plans, with identity verification language appearing nearby; that fed speculation that access would be gated and more regulated than existing plans (@kimmonismus)This triggered concern that Sonnet 5 might launch as the widely accessible but weaker companion to a stronger, more restricted Fable 5, possibly with regional access issues, especially in Europe (@kimmonismus)Additional rumor posts tied a potential Sonnet 5 release directly to a Fable 5 re-release, with some users explicitly saying they assumed Sonnet 5 would “at least” come with Fable news (@kimmonismus, @kimmonismus)After launch, that expectation went unmet. Multiple reactions framed the absence of Fable 5 as the real story: “instead we got sonnet 5” (@kimmonismus) and “It’s been 18 days since Fable 5 was banned” (@theo)Official positioning vs independent interpretationOfficial/vendor framingAnthropic and downstream partners framed Sonnet 5 around agentic capability, coding, tool use, and cost-performance.Official claim: Sonnet 5 is the “most agentic Sonnet yet” and can make plans, use browsers/terminals, and operate autonomously at a level that recently required larger models (@claudeai)Anthropic’s dev account positioned it as frontier-quality coding and tool use at Sonnet pricing, explicitly highlighting 1M context and broad platform availability (@ClaudeDevs)Anthropic-linked summary posts stressed that Sonnet 5 is safer than Sonnet 4.6 overall, with lower hallucination and sycophancy, and that cyber safeguards are on by default, while still acknowledging Opus remains stronger for serious cyber work (@kimmonismus)Anthropic also provided migration tooling/documentation, saying the claude-api skill helps tune prompts, recommend effort levels, and configure advisor mode for Sonnet 5 (@ClaudeDevs)Independent/third-party evaluation framingThird parties largely agreed Sonnet 5 is a real improvement over Sonnet 4.6, but disputed whether it merits a “5.0” naming step or its effective price/performance relative to Opus and peers.Cursor said Sonnet 5 is a meaningful step up on CursorBench: 57% vs 49% for Sonnet 4.6 (@cursor_ai)Cognition said Sonnet 5 outperforms Opus 4.8 on FrontierCode Extended, posting 53.8% score and 57.6% pass rate, while noting benchmark rankings may shift slightly after upcoming adjustments (@cognition, @cognition)Cline highlighted Opus 4.8-level performance on Terminal-Bench for less than half the cost, plus improved resistance to prompt-injection hijacks for “--yolo coders” (@cline)FactoryAI, Perplexity, Cursor, Devin, Droid, Agent Arena, and VS Code all quickly added support or availability announcements, indicating the ecosystem saw it as a relevant default model even where user enthusiasm was mixed (@FactoryAI, @perplexity_ai, @AravSrinivas, @code, @arena, @cognition)Technical detailsCore product specs and pricingContext window: 1 million tokens (@ClaudeDevs, @ArtificialAnlys)Standard pricing: $3/M input, $15/M output (@ClaudeDevs, @ArtificialAnlys)Promotional pricing: $2/M input, $10/M output until Aug. 31 / Sept. 1 depending on wording of the post (@kimmonismus, @ArtificialAnlys)Cache pricing: 25% premium for cache writes ($3.75/M), 90% discount for cache hits ($0.3/M), 5-minute TTL (@ArtificialAnlys)Effort settings: Sonnet 5 adds xhigh, for 5 effort levels total matching Opus 4.8: max, xhigh, high, medium, low (@ArtificialAnlys)Knowledge cutoff (rumored pre-launch): January 2026 (@kimmonismus)Benchmarks and measured deltasA key part of the discussion was that Sonnet 5 improved substantially over 4.6, but usually did not exceed Opus 4.8 on broad intelligence aggregates.CursorBench: 57% for Sonnet 5 vs 49% for Sonnet 4.6 (@cursor_ai)Artificial Analysis Intelligence Index: Sonnet 5 scores 53, a +6 over Sonnet 4.6, placing it #5 overall, roughly tied with GPT-5.5 high reasoning, but still behind Opus 4.7/4.8 (@ArtificialAnlys)Artificial Analysis token usage: Sonnet 5 used ~69k output tokens per task on average, about 40% more output tokens than Sonnet 4.6 (@ArtificialAnlys)Artificial Analysis task cost: at standard pricing, Sonnet 5 cost $2.29 per Intelligence Index task, about 2x Sonnet 4.6 and ~15% more than Opus 4.8, despite lower per-token price, because of higher token usage (@ArtificialAnlys)Agentic turns: Sonnet 5 used ~3x the agentic turns of Sonnet 4.6 on AA-Briefcase and GDPval-AA, and max effort used around 6x more turns than low effort on GDPval-AA (@ArtificialAnlys)CritPt frontier physics benchmark: Sonnet 5 scored 17%, +14 points over its predecessor, but still behind GLM-5.2, Claude Opus, Fable, and GPT-5.5 variants (@ArtificialAnlys)Artificial Analysis also reported notable improvements over Sonnet 4.6 on Terminal-Bench v2.1 (+9), Humanity’s Last Exam (+10), and SciCode (+7) (@ArtificialAnlys)Cognition’s FrontierCode Extended result: 53.8% score, 57.6% pass rate, ahead of Opus 4.8 in their current evaluation (@cognition)Max Bittker noted Runescape benchmark scores improved a lot over Sonnet 4.6, but were still behind nearby Pareto competitors such as GLM 5.2 and Gemini 3.5 Flash (@maxbittker)Tokenization and effective cost quirksOne underappreciated technical detail was the tokenizer/effective billing behavior.S