AI・テクノロジー
xAI's "Grok 3.5" Officially Launched — Enhanced Chain-of-Thought and X Integration Reshape the Structure of Real-Time Reasoning Workflows
機械翻訳 / Machine-translated
On August 8, 2026 (Pacific Time), xAI officially launched its next-generation model "Grok 3.5." Featuring a context window expanded to one million tokens — three times that of the previous generation — combined with native access to real-time data from the X platform, this configuration has the potential to fundamentally transform the "search → analysis → reporting" workflow in social media monitoring, competitive intelligence, and market intelligence.
At 2:00 PM Pacific Time on August 8, xAI announced the availability of Grok 3.5 via its official account. The API became available in 152 countries on the same day, with pricing set at $8 per million input tokens and $24 per million output tokens. The context window has been expanded approximately threefold from Grok 3's 320,000 tokens.
In terms of benchmarks, the model recorded 94.2% on MMLU and 89.1% on GPQA (graduate-level science QA). While it falls slightly short of OpenAI GPT-5's MMLU score of 95.1%, xAI claims it surpassed GPT-5 with a score of 92.7% on its own proprietary "real-time reasoning" evaluation. Inference speed is 2.4 times faster than the previous generation.
Immediately after the release, verification posts surged on X, with breaking-news accounts sharing experimental reports such as the following:
"I had Grok 3.5 use X's live search to ask about 'today's semiconductor stock movements,' and within 3 minutes it compiled price fluctuations for individual stocks along with related news. I might not need my own RAG pipeline anymore."
Grok 3 was released in February 2026, but its access to real-time data was limited to X's search functionality, and its accuracy in processing structured data was considered a weakness. During that period, the successive launches of GPT-5 and Gemini 2.5 Ultra eroded xAI's benchmark advantage within just six months.
Grok 3.5 expands the Chain-of-Thought processing steps from "up to 64 stages" to "up to 256 stages." xAI claims that for tasks requiring multi-step reasoning — such as financial analysis, legal document review, and code generation — accuracy improved by an average of 17 percentage points compared to the previous generation.
Until now, Grok's X integration was limited to "keyword search." Grok 3.5 is designed to aggregate trends from specific hashtags and account groups in chronological order, handling summarization and sentiment analysis as a seamless end-to-end process. This creates a clear competitive relationship with dedicated social media listening tools such as Brandwatch.
One million tokens corresponds to approximately 800,000 Japanese characters, or roughly 1,600 A4 pages. This brings the analysis of entire contracts, financial reports, and source code repositories within reach at a realistic cost. Pressure on the market for dedicated long-document processing tools is likely to intensify.
At $8 per million input tokens, the price is somewhat higher than Claude Sonnet 4.6 ($3/M) or GPT-4o ($5/M). However, when factoring in the included X real-time data, separate collection and retrieval costs are eliminated, meaning the total cost could actually favor Grok 3.5 in use cases focused on social media analysis.
MCP (Model Context Protocol) support is listed as "in preparation," and official integration with LangChain and CrewAI has not been confirmed. Incorporation into autonomous agent frameworks is estimated to be one to two months behind competitors, which may become a bottleneck for full enterprise adoption.
What sets Grok 3.5 apart from a typical LLM release is its ability to use data generated every second by X's one billion users directly as input for reasoning. While other models search the internet broadly, Grok is designed to go deep on a specific platform — this asymmetry becomes a structural advantage in social listening, election analysis, and financial news sentiment analysis.
However, the concerns are clear. The quality of X's data is susceptible to fluctuation depending on the platform's operational policies, and the risk of misinformation and spam contaminating the model's reasoning cannot be eliminated. The trade-off between "timeliness" and "reliability" is an issue that users must consciously address at the design stage.
The current lack of MCP support presents a practical barrier for organizations seeking rapid enterprise deployment. Whether official support arrives within the next 60 days will likely be the deciding factor in adoption rates within the agent market.
Grok 3.5's combination of speed, broad context, and X integration makes it the model most directly suited to business intelligence workflows that originate from social media. While it does not claim the top benchmark position, its differentiating axis — seamless integration with X data — is difficult for other models to replicate. The next focal point is the official announcement of MCP support and agent framework integration; once that is in place, enterprise adoption decisions are expected to move rapidly.
This article was written by an AI writer (AI News) from the Mirai News editorial team.
