> Imported exploration, 2026-09-13. Source claims have not been independently verified by this repository. See [integration review](../docs/integration-review.md).

# Frontier ledger — September 2026

Last human pass: 13 September 2026. Prices and ranks rot quickly. Re-verify against Artificial Analysis, lab pricing pages, and Epoch before any purchase.

Figures below are **indicative public list prices** in USD per million tokens and recent public board readings. Effort settings change everything.

## Usable cluster (hosted)

| Model | Input / output $/M (list, public reports) | Role in Radar language | Availability note |
| --- | --- | --- | --- |
| Claude Fable 5.1 | ~$10 / $50; cache reads cut to ~$0.25 | Frontier-class; often joint AA lead | Generally available; Mythos 5.1 is restricted |
| GPT-6 Astra | reports vary; treat ~$10 / $50 as working assumption until card is stable | Frontier-class; computer-use / ARC-AGI-3 specialist claims | Rollout gated; Pro capacity incidents mid-Sep |
| Claude Opus 5 | ~$5 / $25 | Topnotch generalist; often Efficient vs Fable | Broad |
| GPT-5.6 Sol | promotional cuts reported (~$4 / $20 in some windows) | Topnotch; previous flagship | Broad |
| GPT-5.6 Terra | lower than Sol (reports ~$2.5 / $12–15) | Often Efficient inside OpenAI family | Broad |
| GPT-5.6 Luna | lower still | Sufficient / Budget for many knowledge tasks | Broad |
| Gemini 3.8 Flash | reports ~$0.75 blended class | Sufficient multimodal workhorse; sometimes Budget | GA 2 Sep; watch 2027 price-change notes |
| Grok 4.6 | reports ~$2 / $6 | Value hosted frontier-adjacent; long-horizon agents | Current xAI flagship |
| Muse Spark 1.3 | very low list vs US peers on some trackers | Watch for agentic coding efficiency | Closed Meta line |
| Claude Sonnet 5 | cheaper Claude tier | Sufficient for many writing/coding tasks | Broad |

## Open / exportable cluster

| Model | Role | Note |
| --- | --- | --- |
| Kimi K3 | often strongest open-weight intelligence reading | License and endpoint availability vary by region |
| Qwen3.8-Max | multilingual + strong general | Open-weight flagship path |
| DeepSeek V4-Pro / V4.1 Flash | Budget-to-Sufficient coding & general | V4.1 Flash: smaller active params, MIT, 1M context |
| GLM-5.3 / Flash | open-weight efficiency | Frequent Pareto mention on cost/intelligence |
| Mistral Medium 3.5 | EU-sovereign option | Not always peak score |

## Composite boards (do not mix versions)

- **AA Intelligence Index v4.3** (10 evals including Terminal-Bench 4.0 + AutomationBench-AA): Fable 5.1 max ≈ Astra max ≈ 53; Opus 5 max ≈ 51; Fable 5 ≈ 50; Muse Spark 1.3 max ≈ 48; Sol max ≈ 47. Cost per AA task reported far lower for Astra than Fable 5.1 in AA’s own methodology (~$3.26 vs ~$7.63 in one published comparison).
- **Epoch ECI:** GPT-6 Astra reported at the top of the current staircase (~169), then Fable 5 / Opus 5 cluster.
- **Coding / computer use:** SWE-bench Pro, DeepSWE, Terminal-Bench 4.0, OSWorld 2.0, Frontier Code 1.1 — Astra, Fable 5.1, Opus 5, SWE-2, Grok 4.6 trade blows depending on harness.

## Radar labels (how the Task Router will speak)

- **Frontier** — best expected success on the task’s five-benchmark blend, ignoring price. If two models are within noise, name both and pick the one with better availability.
- **Topnotch** — expected success within 10% *relative* of Frontier on that blend.
- **Efficient** — lowest expected *task* cost among Topnotch (tokens × list price × typical traces, not list price alone).
- **Sufficient** — judged able to complete the task to an acceptable bar (see METHOD).
- **Budget** — lowest expected task cost among Sufficient.

## Changelog

- 2026-09-13: v0.1 ledger from public boards. Not an audit.