**Intelligence Radar — Daily Brief**  
**29 September 2026 (Europe/Berlin)**  
Weather of the frontier: mid-tier models are closing the intelligence gap while prices and token efficiency continue to compress the cost of near-frontier agentic work.

### Frontier & markets
Confirmed cluster of mid-to-high releases in the last 10 days. Anthropic shipped **Claude Sonnet 5.5** (28 Sep) at the same list price as Sonnet 5 ($2 / $10 per MTok input/output, $0.20 cache reads). Anthropic reports 30 %+ faster generation and up to 30 % lower task cost via fewer tokens; on Terminal-Bench 4.0 it scores 70.6 % (vs 66.4 % Opus 5.5 high-effort and 10.3 % Sonnet 5). Artificial Analysis places Sonnet 5.5 (max) at 56 on Intelligence Index v4.3.2 — second behind Opus 5.5 (max ≈58) and ahead of GPT-6 Astra / Fable 5.1 (both 53) — while noting the highest output-token burn measured (~193 k tokens per Index task).

OpenAI released **GPT-6.1 Sol** today (DevDay) as an upgrade to the 22 Sep GPT-6 Sol. Pricing remains $2 / $10 (cached input cut to $0.10). OpenAI states near-Astra performance on agentic coding, computer use and professional work at roughly one-fifth Astra’s standard token prices; DeepSWE v1.1 is reported as matching Astra. Available now in API, ChatGPT Work and Codex (not yet consumer Chat). GPT-6 Sol/Luna themselves halved prior-tier prices relative to GPT-5.6 equivalents.

xAI (SpaceXAI) shipped **Grok 4.7** (21 Sep) on a larger base + longer RL, still at $2 / $6. Vendor numbers put it near the price-performance frontier on CursorBench 4.0 (46.3 %) and competitive on DeepSWE / EEBench. Context 500 k.

Earlier September: Claude Opus 5.5 ($4 / $20), GPT-6 Astra ($10 / $50), Muse Spark 1.3, DeepSeek V4.1 Flash ($0.30 / $1.20), Xiaomi MiMo-V2.6-Pro/Flash (open-weight leaders on several boards), Gemini 3.8 family updates. Artificial Analysis Intelligence Index remains on v4.3.2 (Terminal-Bench 4.0 + AutomationBench-AA; private sets ~40 %). Cyber Index launched; Grok 4.7 (xhigh) and MiMo-V2.6-Pro tie at 56 with a ~65× cost gap. No capacity pauses or regional blocks reported as primary events. Terminal-Bench 2.x nearing saturation at the top; OSWorld-Verified still shows open-weight strength (Qwen3.8 Max 86.1 %).

### Science of intelligence
Measurement work continues to move beyond saturated exams. Artificial Analysis v4.3 series explicitly weights agentic professional work (AA-Briefcase, GDPval-AA v2.1, AutomationBench-AA) and private test sets. Epoch Capabilities Index data remain current (frontier advanced ~14 points/year since reasoning models).  

New primary theory pieces: arXiv 2609.35618 proposes a five-level hierarchy (behavioural → organism-environment) for assessing AI consciousness, mapping major theories and producing Bayesian credences; indicators overlap heavily with general-intelligence architectural features. arXiv 2609.24555 (“Endless Exam”) introduces verifiable mathematical-construction families that remain below published human frontiers, with continuous quality scores across nine models. BioEVAL (arXiv 2609.30489) supplies a multi-institutional PhD-level bioengineering suite (MCQ + synthesis + multimodal). Stanford AIMS textbook (updated early Sep) formalises measurement science for AI evaluation (validity, IRT, Bradley-Terry, error decomposition). These are theory/measurement contributions, not product claims.

### Engineering
Agentic harnesses dominate: Terminal-Bench 4.0, OSWorld-Verified, CursorBench, DeepSWE, AA agentic suites. Sonnet 5.5 and GPT-6.1 Sol both emphasise fewer tool calls / better self-verification on long-horizon coding and computer-use. OpenAI DevDay highlighted always-on agents (“dots”) with dedicated cloud computers (Pro/Business). Inference efficiency remains the binding constraint: cache-price cuts (OpenAI $0.10, Anthropic $0.20) and token-burn differences are first-class. No new public chip or energy primaries today; Epoch data-centre coverage continues to expand (updated 28–29 Sep).

### Political / legal / social
EU Digital Omnibus on AI (in force since late July) has delayed high-risk system obligations to Dec 2027 (stand-alone) / Aug 2028 (embedded). Transparency rules for synthetic content and GPAI enforcement powers already apply; new prohibition on non-consensual intimate / CSAM generation effective Dec 2026. Implementation lag and competitiveness concerns continue to be noted in secondary analysis. No major US federal or Chinese regulatory primary moves reported in the last 48 h. Anthropic continues threat-intelligence disclosures on misuse patterns.

### Watchlist hits (primary)
- Anthropic Claude Sonnet 5.5 announcement & platform docs: https://www.anthropic.com/claude-sonnet-5-5  
- OpenAI GPT-6.1 Sol: https://openai.com/index/introducing-gpt-6-1-sol/ (+ system-card addendum)  
- xAI Grok 4.7: https://x.ai/news/grok-4-7  
- Artificial Analysis Sonnet 5.5 Index note: https://artificialanalysis.ai/articles/claude-sonnet-5-5  
- AA Intelligence Index v4.3: https://artificialanalysis.ai/articles/artificial-analysis-intelligence-index-v4-3  
- Epoch data (models, ECI, data centres): https://epoch.ai/data  
- arXiv 2609.35618 (consciousness hierarchy), 2609.24555 (Endless Exam), 2609.30489 (BioEVAL)

### Ledger actions
- **Frontier label**: Sonnet 5.5 (max) now sits inside the top-2 band on AA Index v4.3.2; GPT-6.1 Sol claims near-Astra on coding/computer-use boards — both warrant re-evaluation on the five-benchmark atlas (AA Index, Terminal-Bench 4.0, OSWorld-Verified, DeepSWE/SWE-bench variant, GDPval-AA).  
- **Efficient / Budget**: GPT-6 Luna ($0.10/$0.50) and DeepSeek V4.1 Flash remain strong Budget candidates; GPT-6.1 Sol and Sonnet 5.5 tighten the Efficient band on agentic cost-per-task.  
- Rebase needed once independent AA runs of GPT-6.1 Sol appear and once Terminal-Bench 4.0 / AutomationBench fully separate from saturated 2.x boards. No single “best” model without task specification.

Sources: primary lab pages and Artificial Analysis / Epoch / arXiv links above; secondary corroboration from contemporaneous reporting only where it points back to primaries.

Ask Intelligence Radar a task for a Task Router ticket (5 benchmarks → Frontier / Efficient / Budget + optional decomposition).