1.3 Inference engines and models

Book 2 · Delegated IntelligenceChapter 1 · section 3 of 14

An inference engine interprets context and produces language, structured data, classifications, plans, code, or other predictions. The form it takes in 2026 is a large language model — hosted or local, multimodal or text-only — plus the supporting cast that shapes what it produces: embedding models that turn text into vectors, rerankers that order retrieved documents, classifiers that route work between systems. An inference engine has no organizational authority on its own. Its output becomes part of delegated intelligence only when another system gives it a role, an output contract, and a way to evaluate the result. In the component language of Chapter 3, the engine supplies the nondeterministic interpretation; everything that bounds it — tools, memory, directives, permission envelope — is supplied by the layers surveyed in the rest of this section.

1.3.1 The proprietary frontier

The proprietary frontier is a longer list than it was a year ago, and the conversation around it is louder than the conversation around any other layer in this chapter. These are the models that get the keynote slots, the magazine covers, and the breathless weekly launch coverage. They are also the models that providers frame as the most capable, the most dangerous, and the most worth paying for. It is what gets talked about, so the survey starts here.

The list of vendors with a credible proprietary frontier line at this writing runs from the American and Chinese platforms most readers have heard of, through a set of mostly Chinese labs whose products compete in the same league but rarely surface in English-language press, to one or two commercial holdouts that are positioning around specialization rather than raw capability:

  • OpenAI. GPT-6 Astra, released September 3, 2026, is the flagship — a one-million-token-class model priced at $10 input and $50 output per million tokens at standard short-context rates. GPT-6 Sol ($2 input, $10 output) and GPT-6 Luna ($0.10 and $0.50) arrived September 22, lowering the price of the general-purpose tiers. A week later, on September 29, GPT-6.1 Sol kept the $2/$10 rate card and halved cached-input pricing to $0.10 per million tokens. OpenAI positions it near Astra on agentic coding, computer use, and professional work at one-fifth of Astra’s token prices. On October 26, GPT-6.1 Terra filled the mid-tier at $1 input and $5 output per million tokens — half of Sol’s rates and the first Terra-class model since GPT-5.6 — positioned around visual reasoning, precise computer use, and high-volume routine work. The GPT-5.6 family remains available as the predecessor generation; Sol’s $4/$20 promotional rate is published through November 30, 2026. OpenAI also sells a trusted-access tier: GPT-6 Rosalind, a frontier reasoning model for biology and drug discovery, runs on unchanged GPT-6 Astra weights with adjusted refusal boundaries, is priced at $15 input and $75 output per million tokens, and is restricted to approved life-sciences work. On November 5, 2026, OpenAI added GPT-6 Cyber, an Astra-based variant post-trained for authorized vulnerability research and exploit development, sold through the Daybreak Red trusted-access program at $20 input and $100 output per million tokens. OpenAI credits the model with 948 Linux privilege-escalation exploits and 81 previously unknown high-severity Firefox vulnerabilities, and classifies it Critical in cybersecurity under its Preparedness Framework.1011
  • Anthropic. Claude Fable 5.1, generally available September 1, held the premium rung at $10 input and $50 output per million tokens until November 9, 2026, when Fable 5.2 took it at $8 input and $40 output per million tokens — twenty percent below 5.1 on both sides, on the same million-token context — with the gated Mythos 5.2 listed at the same rates.12 Fable 5.1 remains listed at its earlier rates. Cheaper cache reads cut typical bills about 25 percent and highly agentic ones as much as 45 percent in Anthropic’s reported usage. The Claude 5.5 family fills the public ladder: Opus 5.5 (September 22) at $4/$20 and Sonnet 5.5 (September 28) at $2/$10. Anthropic reports that Opus performs at Fable’s level on most work and costs 40 percent less per task than Opus 5; Sonnet runs more than 30 percent faster and costs up to 30 percent less per task than Sonnet 5. Haiku 5.5 shipped October 7 at $0.10/$0.50 for prompts up to 100,000 tokens, rising to $0.50/$2.50 above that threshold. Mythos 5.1 is the same base model as Fable with different safeguards, reserved for vetted US organizations working in cybersecurity and the life sciences.
  • Google. The Gemini 3 family still spans Pro through Flash. Gemini 3.8 Flash, released September 2, is the current workhorse Flash — $0.75 input and $3.75 output per million tokens on an introductory rate through the end of 2026 — with a restricted 3.8 Flash Cyber variant sold only through Google’s Fairwind program for trusted defenders. Gemini 3.1 Pro Preview remains available at $2/$12 for prompts up to 200,000 tokens and $4/$18 above that threshold. Google’s next frontier model, Gemini 4 Argon, was announced September 30, 2026 for long-horizon software engineering, enterprise knowledge work, and defensive cybersecurity: an introductory $2 input and $10 output per million tokens (cached input priced at 95 percent off the input rate), rising to $4 and $20 after the introductory period, an output limit raised to one million tokens, and a phased rollout that began with trusted cyber defenders through the Fairwind program. On October 13, 2026, Google made the model generally available in the Gemini API, with the introductory rate running through November 30 before the $4 and $20 rates apply. On October 28, 2026, Google announced the next model in the line, Gemini 4 Carbon — its strongest, with a state-of-the-art cybersecurity emphasis — at the same introductory $2/$10 rate card and cached input at 95 percent off, rising to $4 and $20 after the introductory period; access is phased from a subset of cyber defenders through the Fairwind program before developers and consumers get it.
  • xAI. Grok 4.7, released September 21 at Grok 4.6’s prices, tops out the line — a half-million-token context window and positioning aimed squarely at long-running agents.
  • Meta. Muse Wonder, released October 12, is Meta’s first frontier-class model on its Model API — a one-million-token-context model at $4 input and $20 output per million tokens, with cached input at $0.20, positioned around frontier coding, long-running agents, and computer use. Its stronger sibling, Muse Wonder Full, is not on the API at all: it ships only inside the Muse Code subscription. Meta reports Wonder Full topping agentic and coding benchmarks including DeepSWE and SWE-Marathon in independent third-party runs — vendor-curated comparisons, not production guarantees.
  • Microsoft. The MAI family expanded at Build 2026 in June, with MAI-Thinking-1 as the reasoning flagship. Microsoft’s technical report gives it 52.8 percent on SWE-Bench Pro — a vendor-reported result, but a respectable debut and a sign that the company is no longer content to resell someone else’s frontier.13
  • Amazon. The original Nova family shipped four language and multimodal tiers (Micro, Lite, Pro, Premier) plus Canvas and Reel for image and video, all running natively inside AWS. Nova Forge lets enterprises start training from early checkpoints and blend their own data with Nova-curated training data on managed SageMaker infrastructure.
  • Baidu. ERNIE 5.0, introduced at Baidu World in November 2025, is a trillion-parameter model built for unified understanding and generation across text, images, video, and audio. The ERNIE 5.1 release announced in May derives a smaller model from that foundation for agentic and reasoning work.
  • ByteDance. Seed 2.0, released February 14, 2026, is part of the model family behind Doubao. ByteDance followed it with Seed 2.1 on June 23, emphasizing long-horizon agents, multimodal work, and coding. Its published evaluations put the family alongside Western frontier models; the useful comparison is the task, serving terms, and price offered to your organization.
  • Alibaba. Qwen3.8-Max is the hosted flagship based on the 2.4-trillion-parameter Qwen3.8-2.4T-A95B checkpoint. The hosted model adds features, including vision input and built-in tools, that the downloadable text-only checkpoint does not provide. Buyers need to distinguish the API product from the weights they can run themselves.

What sets these models apart from the rest of the market is not one capability. It is the combination of large training investments, long context windows, tool use, and the engineering work needed to keep the harnesses, SDKs, and hosted services coherent. Frontier work also costs a lot of money, and the frontier is becoming a major component of the human economy. Meta alone projected $130 billion to $145 billion in capital spending for 2026 in its second-quarter filing. The commitments extend beyond the current year: Meta and Alphabet reported more than $364 billion in combined future payments on leases that had not yet commenced as of June 30, largely for data centers and related infrastructure, with some terms reaching thirty years.14

A new headline-tier model arrives almost every week from somewhere on this list. Every release is covered as the new state of the art; every prior release is framed as having been surpassed. Industry coverage tracks the leaderboard more closely than it tracks what the systems actually do. A small lead on one benchmark does not tell an orchestrator whether the new model will improve the work. Price per token, usable context, tool-use behavior, latency, and deployment surface often decide the choice before the leaderboard does.

1.3.2 The open-weight frontier

Open-weight models compete directly with proprietary frontier models on a growing set of workloads. Always-on agents make their economics especially useful. OpenClaw, a local-first open-source runtime with hundreds of thousands of GitHub stars, includes a heartbeat scheduler that wakes the agent on a configurable interval.15 A consumer chatbot that costs a dollar per long conversation is one thing; an agent that makes dozens of calls an hour, every hour, is another. Low-cost routing lets routine checks run continuously while expensive models handle work that needs them. Repeated calls turn the price per call into an architectural constraint.

The open-weight frontier spans several deployment classes, each with a different buyer in mind:

  • Full scale. DeepSeek V4-Pro, generally available August 13, 2026, has roughly 1.6 trillion parameters and MIT-licensed weights, with API output pricing of $1.98 per million tokens off-peak and $3.96 at peak. DeepSeek also publishes MIT-licensed V4-Flash-Vision-Exp weights; its API now serves V4.1 Flash in place of the older Flash and Vision-Exp endpoints. Moonshot AI’s Kimi K3 has 2.8 trillion parameters, a one-million-token context window, and its own Kimi K3 License; the official API charges $3 input and $15 output per million tokens. Moonshot’s current API flagship, Kimi K3.1 Pro (October 23, 2026), is a post-trained version of K3 — one-million-token context, $2 input and $10 output per million tokens, with a faster K3.1 Pro Highspeed tier; the full weights shipped on schedule by November 4, 2026, under the Kimi K3.1-Pro license. Alibaba’s downloadable Qwen3.8-2.4T-A95B has 2.4 trillion parameters under the Qwen3.8-Max license. Z.ai’s GLM-5.3 has about 750 billion parameters under a custom license, with a security-review requirement for very large model-as-a-service businesses. Z.ai reports strong results against Kimi K3 on several agentic benchmarks, using Claude Code for part of the evaluation suite. Meta released Muse Spark Open on October 15, 2026: a coding-optimized mixture-of-experts model of roughly 816 billion parameters, 42 billion active per token, with a one-million-token context window, downloadable under the custom Muse Model License — Meta calls it the most capable US open-weights model to date.16
  • Mid scale. NVIDIA’s Nemotron 3 Ultra at 550 billion parameters, with weights under OpenMDW 1.1 and published training data and recipes; Mistral’s Medium 3.5; Baidu’s open-weight ERNIE 4.5 family.
  • Smaller and locally served. Google’s Gemma 4 (Apache 2.0); Microsoft’s Phi-4 family (MIT); Mistral’s Small 4 (Apache 2.0); OpenAI’s gpt-oss at 120 billion and 20 billion parameters (Apache 2.0); Meta’s Muse Glimmer at 30 billion parameters (Apache 2.0); Nous Research’s Hermes 4.3 at 36 billion parameters, trained on the Psyche decentralized network and licensed under Apache 2.0. These cover very different hardware budgets: Gemma’s smallest variants target phones and edge devices, while Mistral Small 4 has 119 billion total parameters and belongs in a different deployment class.

These are production candidates, with materially different capability and deployment requirements. The properties an orchestrator needs to check are where the weights live, what license governs commercial use, what hardware the model fits on, and whether the vendor publishes the recipes needed to fine-tune or distill on top of it.

The price overlap is now as interesting as the capability overlap. GPT-6 Luna arrived September 22 at $0.10 per million input tokens and $0.50 per million output, following the July reduction in GPT-5.6 Luna’s prices.17 Haiku 5.5 now starts at the same rates for shorter prompts. An open-weight model gives you deployment choices; a proprietary API can still be the cheaper route. The choice needs both a workload evaluation and a bill.

1.3.3 The economics of inference

Not every component in this survey gets its own economics discussion — inference does, because the models an orchestrated system runs are one of the biggest costs of the whole arrangement, and there will rarely be just one: most real systems call several models, each priced differently. Choosing them well is one of the most consequential decisions an orchestrator makes, and it moves cost and quality at the same time.

The economics reach deeper than model choice, and they change system design. The standard short-context rates, per million tokens: GPT-6 Astra and Claude Fable 5.1 at $10 input and $50 output; GPT-6.1 Sol, Opus 5.5, Sonnet 5.5, and Meta’s Muse Wonder at $2 to $4 input and $10 to $20 output; Gemini 3.1 Pro Preview at $2/$12; GPT-6.1 Terra at $1 input and $5 output; Gemini 3.8 Flash at an introductory $0.75/$3.75. Argon is generally available in the Gemini API at its introductory $2/$10, a rate that runs through November 30 before the $4/$20 list applies.18 Mythos 5.1 is listed at Fable’s rates but sold only through trusted-access programs.19 Hosted open-weight output ranges from DeepSeek V4.1 Flash’s $0.60 off-peak to Kimi K3’s $15, with GLM-5.3 at $4.40. That spread can decide whether a continuously running component is economical. A heartbeat that reads 300,000 input tokens and writes 2,000 output tokens fits DeepSeek V4.1 Flash’s one-million-token window and costs about five cents off-peak; the same token counts on Fable 5.1 cost $3.10. Twenty-four off-peak-priced calls cost about $1.11 versus $74.40. A thousand-agent fleet makes that about $1,110 versus $74,400 a day, before caching or discounts.20 A fleet that runs around the clock also incurs DeepSeek’s peak rates during the published weekday peak hours. These are the sorts of arithmetic an orchestrator does when designing a system.

Price is also not one dial. The bill depends on reasoning effort, because thinking tokens can dominate a call; processing path, with batch and flex tiers often half the standard rate; caching, where stable context can become much cheaper to read; and context length. Crossing a pricing threshold can reprice the whole request. For GPT-6 Astra, GPT-6.1 Sol, GPT-6.1 Terra, and GPT-6 Luna, prompts above 272,000 input tokens double input and cache rates and raise output rates by half. The 300,000-input, 2,000-output heartbeat would therefore cost $6.15 on Astra at standard rates. Haiku 5.5 has a different threshold: above 100,000 input tokens, its input and output rates are five times the short-prompt rates. Model choice sets the price range; effort, batching, caching, and context decide where the bill lands.

OpenRouter, the routing service that puts hundreds of models behind one API, publishes a useful view of how its users move between providers. Its rankings measure token traffic, not quality or the whole market. In its June 30 report, DeepSeek’s share of OpenRouter tokens rose from 9 percent in January to 18 percent in June, with agentic work driving most of the gain; DeepSeek had led token flow by model author since mid-May.21 Promotions add another moving part. Budget on the published rate that applies to your traffic, record the discount’s end date, and treat continued promotional pricing as an upside.

Take a modest production workload — an internal documentation agent answering employee questions, moving thirty million input tokens and three million output tokens a month. Run everything on DeepSeek V4.1 Flash off-peak ($0.15 per million input, $0.60 per million output) and the month costs $6.30. Run everything on Claude Fable 5.1 at its $10 per million input and $50 per million output list rates, and the same month costs four hundred and fifty dollars before the cheaper cache reads.22 That is about a seventy-one-fold difference for the same token counts.

The capability gap still matters. A cheap tier that passes routine classification and summarization can fail on long, multi-step reasoning; a model that leads a coding evaluation may add little to an employee FAQ. The orchestrator’s question is what fraction of this workload needs the more expensive model. If five percent of the documentation traffic, measured by both input and output tokens, needs Fable 5.1 and the rest passes evaluation on V4.1 Flash, the month costs about $28.50 instead of $450 — a reduction of roughly 94 percent. The routing decision earns that saving only if the cheaper route still does the work.

At that price gap, work that would be prohibitively expensive on a frontier model becomes realistic on a small or open-weight one. Fan-out that runs ten attempts on a cheap model and keeps the best one stops being expensive. An evaluator model that critiques every output of a stronger model becomes a standard pattern instead of a luxury. A routing layer that sends easy work to a small local model and hard work to the frontier becomes the default architecture, not an optimization. Cache-hit pricing on the open-weight side drops input costs by another order of magnitude, which is why long-context agent systems — which re-read the same documents many times — increasingly run on cheap open-weight models with caches warm.

None of this makes a model swap free. A system wired to one provider’s tool-calling quirks and prompt formats does not move by changing a model string. Sometimes a swap works with no visible degradation, but more often than not, when you switch between two high-priced frontier models, you learn that the memory, the skills, and the context need to be tuned in subtle and nuanced ways to adapt to the new model. The harnesses and orchestration systems surveyed in this chapter make the swap feasible, and reusable evaluation sets tell you whether the new model passes your actual work before you commit.

Every model has a personality. Two inference engines might sit next to each other on the same benchmark leaderboard, but use them at their limits and you find each one is better at some things than others, in ways the leaderboard does not show. An orchestrator running several models at once ends up in an odd role: you turn into a kind of psychiatrist for a new model. One of the first things you have to do is figure out its hangups — what it is good at, what it refuses, what it overcomplicates, where it quietly drifts. This is a significant amount of effort, and it is part of the real cost of a model swap.

And cost awareness comes with the role. Model spend can be one of the largest line items — alongside hosting, storage, and tooling — and the orchestrator is the person positioned to see it whole: the application team sees per-call costs, finance sees an invoice, and the person who owns the routing, the effort dials, and the evaluation results sees all three at once.

1.3.4 Workload types

Not every part of an orchestrated system needs the strongest model available, and knowing which parts need what is one of the ways the bill stays sane. The work that inference engines do inside one of these systems falls into a handful of recognizably different kinds:

  • Routine calls. Classification, extraction, summarization, formatting, the hourly heartbeat that checks whether anything changed. The output is short, the stakes are low, and a small or open-weight model does the job. This is also most of the call volume, which is why routing it cheaply matters more than any single clever optimization.
  • Tool use and function calling. The model has to emit a correctly formatted call to the right tool with the right arguments, every time, and not invent calls that do not exist. This is a reliability test more than an intelligence test, and some cheap models are excellent at it while some expensive ones are erratic.
  • Coding and repository work. Understanding a codebase, planning a multi-file change, writing the diff, running the tests. This is the workload SWE-bench family benchmarks measure, and it is one place to measure differences between models.
  • Reasoning-heavy analysis. Long chains of inference over evidence — technical due diligence, incident analysis, cross-document synthesis. The general-reasoning benchmarks measure this, and it is the workload where overdelegation without a strong model produces confident nonsense.
  • High-frequency agent loops. Dozens or hundreds of small calls per hour, every hour: the always-on agents. The per-call capability bar is modest; the cost bar is everything.
  • Specialist domains. Medicine, law, finance, science. Domain benchmarks exist, and the choice here is often dictated less by benchmark scores than by jurisdiction, licensing, and regulatory rules about which models are allowed to touch which data.

The job is matching the engine to the workload, and the two levers are cost and quality: a cheap model on a hard workload fails the workload, and an expensive model on a trivial workload fails the budget.

1.3.5 Benchmarks

Benchmarks matter to orchestration for one reason: they give us a shared vocabulary for talking about capability across models and vendors. When a vendor says a model is “smarter,” the orchestrator’s next question is on which benchmark, against whom, at what price — and the answer to that question is the difference between routing decisions that hold up and routing decisions that collapse the first time the work gets hard.

The benchmarks an orchestrator wants to know are the ones that match the workloads above:

  • SWE-bench (Verified, and the newer Pro). Real GitHub issues in real repositories, multi-file diffs, tests must pass. The standard measure of coding ability.
  • GPQA Diamond. Graduate-level, Google-proof multiple-choice questions in physics, chemistry, and biology — the standard measure of hard general reasoning.
  • BFCL (Berkeley Function-Calling Leaderboard). Graded function calls: right function, right arguments, right types, no invented calls. The measure of tool-use reliability, and one where some cheap models beat expensive ones.
  • tau-bench family. A model plays a support agent with a tool panel and a demanding user, scored on whether the task actually completes. The current tau-three release adds knowledge retrieval and voice tasks. The measure of multi-turn tool use under friction.
  • Terminal-Bench. Real tasks in a real terminal: install, configure, fix, build. The measure of agentic computer use, across a wide range of environments.
  • HLE (Humanity’s Last Exam). Expert-written questions across many fields; a difficult test of cross-domain knowledge and reasoning. Useful for exposing limits, provided you compare the same version and tool conditions.23
Figure 15. Models in one harness. CursorBench 4.0 scores for nine selected models, using each model’s highest published score and the effort shown. Source: Cursor, October 16, 2026.

Figure 15 keeps the harness and benchmark version common, while showing the effort used for each model. Cursor measures ambiguous, multi-file coding tasks drawn from its own sessions; it warns that small score differences may fall within normal variance.24 That makes the figure a useful comparison within one environment. Model releases and task updates will move the scores. The durable practice is to track evaluations that resemble your workloads, then test the candidate in your own system.

1.3.6 Reading a model as a component

The properties an orchestrator reads off a model are the same ones an architect reads off any other component.

Property What to ask Why it matters for orchestration
Context window How many tokens fit in one call? Determines whether memory management is a convenience or a survival skill
Tool-use behavior Does it call tools reliably, and can it be constrained to a schema? The difference between a component and a liability in a multi-step run
Deployment target Hosted API, private cloud, on-device? Sets the data-sensitivity ceiling and the exit options
Cost per million tokens Input and output, with and without caching? At a 10x spread, architecture becomes an economic decision
License Open weights, API-only, restricted program? Determines inspectability, self-hosting, and how long the choice stays yours
Multimodality Does it take images, audio, PDFs natively? Decides whether preprocessing is a separate system or a feature
Sovereignty Which jurisdiction does it run in, and are you allowed to use it where you operate? Organizations and governments increasingly have rules that dictate which models may touch which data, and the list of compliant options can be short

None of the rows is about which model is smartest. All of them are about what the engine can be connected to — which is the whole job.

There are likely another 20 or 30 factors that could go into the choice — some are legal restrictions, some are emerging regulatory concerns, some are vendor-specific gotchas that only surface in production. The space is incredibly active, the factors multiply every quarter, and the practical move is to be clear about your own constraints (jurisdiction, budget, data sensitivity, exit options) and to re-check the market when those constraints change.

1.3.7 Where models show up for an orchestrator

An orchestrator encounters models through harnesses rather than raw APIs. Every runtime surveyed later in this chapter — Cursor, Claude Code, OpenClaw, Hermes Agent, Goose, Pi — puts a model picker in front of the user, and most now accept several providers plus local models. The consequence is that model choice is a standing configuration decision inside the orchestrator’s system, not an annual procurement decision. Chapter 7 returns to this at the level of architecture — deciding which step needs which caliber of judgment is the same decision as deciding which step needs a model at all.


  1. Vendor lineups rechecked November 7, 2026: OpenAI model documentation and changelog, https://developers.openai.com/api/docs/models/gpt-6-astra, https://developers.openai.com/api/docs/models/gpt-6.1-sol, https://openai.com/index/introducing-gpt-6-1-terra, https://developers.openai.com/api/docs/changelog, and pricing, https://developers.openai.com/api/docs/pricing; Anthropic, https://www.anthropic.com/claude-fable-and-mythos-5-1, https://www.anthropic.com/claude-opus-5-5, https://www.anthropic.com/claude-sonnet-5-5, and Haiku 5.5’s October 7 release, https://www.anthropic.com/claude-haiku-5-5; GPT-6 Cyber, announced November 5, 2026, https://openai.com/index/introducing-gpt-6-cyber with the system card at https://deploymentsafety.openai.com/gpt-6-cyber; Google, https://blog.google/innovation-and-ai/models-and-research/gemini-models/3-8-flash-and-3-8-flash-cyber/, https://blog.google/innovation-and-ai/models-and-research/gemini-models/gemini-4-argon/, and Argon’s Gemini API model documentation, https://ai.google.dev/gemini-api/docs/models/gemini-4-argon; Gemini 4 Carbon announced October 28, 2026, https://blog.google/innovation-and-ai/models-and-research/gemini-models/introducing-gemini-4-carbon/; xAI, https://x.ai/news/grok-4-7 and https://docs.x.ai/developers/models/grok-4.7. Meta’s Muse Wonder, released October 12, 2026, https://dev.meta.ai/models/muse-wonder, launch post https://research.meta.ai/blog/introducing-muse-wonder/, and model card https://research.meta.ai/static/muse-wonder-model-card/. Capability and per-task efficiency comparisons are the vendors’ published results, not independent production guarantees.↩︎

  2. OpenAI’s pricing page “Life sciences models” tier: gpt-6-rosalind at $15.00/$75.00 per million tokens (cached input $1.50), with gpt-rosalind-research and gpt-rosalind-discovery at $5/$25 and access limited to approved research through the trusted-access program, https://developers.openai.com/api/docs/pricing (rechecked November 3, 2026). Model details per the system card addendum for GPT-Rosalind-6, published October 30, 2026, https://deploymentsafety.openai.com/gpt-rosalind-6. Rechecked November 7, 2026 against the pricing page’s “Life sciences models” tier, unchanged.↩︎

  3. Claude Fable 5.2 became generally available on Amazon Bedrock on November 9, 2026, at Global cross-Region rates of $8 input and $40 output per million tokens; US Geo and in-Region inference run 10 percent higher ($8.80/$44.00). Sources: AWS what’s-new, AWS ML blog, Bedrock pricing page, and rate verification at DevelopersIO. Mythos 5.2 is the same base model with broader cyber and bio capability, sold only through Anthropic’s vetting program; access is gated and requires approval from an Anthropic account team on Bedrock. Rechecked November 10, 2026.↩︎

  4. Primary product sources rechecked October 7, 2026: Microsoft’s MAI-Thinking-1 technical report, https://microsoft.ai/pdf/mai-thinking-1.pdf, reports 52.8 percent on SWE-Bench Pro; Amazon Nova, https://aws.amazon.com/nova/models/, and Nova Forge, https://aws.amazon.com/nova/forge/; Baidu’s ERNIE 5.0 technical report, https://arxiv.org/abs/2602.04705, November 2025 unveiling in its 6-K, https://ir.baidu.com/static-files/02c1a929-82f9-4988-96e3-899223a474b2, and May 2026 ERNIE 5.1 release, https://ernie.baidu.com/blog/posts/ernie-5.1-0508-release/; ByteDance’s release portfolio, https://seed.bytedance.com/en/seed_model_portfolio, and Seed 2.1, https://seed.bytedance.com/en/seed2_1; Qwen’s official checkpoint card distinguishes the text-only weights from the hosted Qwen3.8-Max product, https://huggingface.co/Qwen/Qwen3.8-2.4T-A95B. Product positioning and benchmark results are vendor reports.↩︎

  5. Meta’s Form 10-Q for June 30, 2026, https://www.sec.gov/Archives/edgar/data/1326801/000162828026050705/meta-20260630.htm, projects $130 billion to $145 billion in 2026 capital expenditures and reports $278.99 billion in leases not yet commenced, with terms up to thirty years. Its additional July leases of about $68 billion are excluded from the June 30 comparison. Alphabet’s June 30 Form 10-Q, https://www.sec.gov/Archives/edgar/data/1652044/000165204426000071/goog-20260630.htm, reports $85.2 billion of future payments under leases not yet commenced, primarily for data centers, with terms up to twenty-six years. The combined $364.19 billion is this book’s addition of these two comparable-date disclosures, not annual capital spending or a total for all providers. Rechecked October 7, 2026.↩︎

  6. OpenClaw, https://docs.openclaw.ai/ and https://openclaw.ai (verified August 29, 2026). Open-source MIT-licensed local-first AI agent runtime created by Peter Steinberger; reached 346,000+ GitHub stars within five months of release; the OpenClaw Foundation became a non-profit in June 2026. The always-on agent cost discussion is documented in the OpenClaw community’s own guides and the cost surveys cited by the project, including the OpenClaw pricing guide at https://openclawai.io/blog (DeepSeek V3 at ~$0.27 per million input tokens used as the default routing target; Claude Haiku 4.5 cited as a budget daily-driver at ~$6 per million combined tokens) and https://www.glbgpt.com/hub/openclaw-cost-pricing-guide (24/7 OpenClaw deployments $15–$300+ per month depending on model choice). The pressure-on-pricing claim is this book’s synthesis, not a single vendor’s statement.↩︎

  7. Official model cards and licenses, rechecked October 7, 2026: DeepSeek V4-Pro, https://huggingface.co/deepseek-ai/DeepSeek-V4-Pro, and Vision-Exp, https://huggingface.co/deepseek-ai/DeepSeek-V4-Flash-Vision-Exp (MIT); Kimi K3, https://huggingface.co/moonshotai/Kimi-K3 (Kimi K3 License); Qwen3.8, https://huggingface.co/Qwen/Qwen3.8-2.4T-A95B (Qwen3.8-Max license); GLM-5.3, https://huggingface.co/zai-org/GLM-5.3, and actual license, https://huggingface.co/zai-org/GLM-5.3/raw/main/LICENSE (security review applies when a licensee or affiliate runs a model-as-a-service business and aggregate twelve-month revenue exceeds $10 billion); NVIDIA Nemotron 3 Ultra report, https://arxiv.org/abs/2606.15007, and BF16 model card, https://huggingface.co/nvidia/NVIDIA-Nemotron-3-Ultra-550B-A55B-BF16 (550B parameters; current OpenMDW 1.1 license), https://raw.githubusercontent.com/OpenMDW/OpenMDW/refs/heads/main/1.1/LICENSE.OpenMDW-1.1; ERNIE 4.5 open-model announcement, https://ernie.baidu.com/blog/zh/posts/ernie4.5/; Mistral catalog, https://docs.mistral.ai/models (Medium 3.5 Modified MIT; Small 4 Apache 2.0), and Small 4’s 119-billion-parameter size, https://mistral.ai/news/mistral-small-4; Mistral Large 4 entered public preview October 6, 2026, a 1-trillion-parameter MoE with 52 billion active parameters, natively multimodal; its full open weights were released October 29, 2026 on Hugging Face as mistralai/Mistral-Large-4-1T-A52B under the Mistral Ecosystem Open-Weight License, a modified MIT license that requires a separate commercial license for model-as-a-service use, https://mistral.ai/news/mistral-large-4, model card https://huggingface.co/mistralai/Mistral-Large-4-1T-A52B (Mistral Large 4 rechecked November 1, 2026); Gemma 4, https://blog.google/innovation-and-ai/technology/developers-tools/gemma-4/ (Apache 2.0); Phi-4, https://huggingface.co/microsoft/phi-4 (MIT); gpt-oss, https://developers.openai.com/api/docs/models/gpt-oss-120b; Muse Glimmer, https://dev.meta.ai/models/muse-glimmer (Apache 2.0); Hermes 4.3, https://huggingface.co/NousResearch/Hermes-4.3-36B (Apache 2.0; Psyche training). DeepSeek release chronology: https://api-docs.deepseek.com/updates/. Kimi’s official API pricing and 1M context: https://forum.moonshot.ai/t/kimi-k3-is-here-our-most-capable-model/480. Moonshot’s K3.1 Pro, a post-trained K3 flagship, reached the API on October 23, 2026 at $2/$10 with a K3.1 Pro Highspeed tier, with the full weights released by the promised November 4 date under the Kimi K3.1-Pro license, https://huggingface.co/moonshotai/Kimi-K3.1-Pro — the license requires a separate agreement for model-as-a-service businesses above $20 million in twelve-month revenue and prominent attribution for products above 100 million monthly active users (checked November 5, 2026): https://forum.moonshot.ai/t/kimi-k3-1-pro-has-launched-start-exploring-now/629 and https://platform.kimi.ai/docs/pricing/chat. A license must be checked for the particular checkpoint, not inferred from the family name. Meta released Muse Spark Open on October 15, 2026 (checked October 17, 2026): 816B total/42B active parameters, 1M-token context, text output, under the Muse Model License, https://research.meta.ai/blog/muse-spark-open, model card https://huggingface.co/meta-models/Muse-Spark-Open-816B-A42B; Reuters reported the release the same day, https://www.reuters.com/business/meta-releases-open-weight-muse-spark-model-coding-agentic-tasks-2026-10-15. The Muse Model License requires “Built with Muse Spark Open” attribution and a separate Meta agreement for model-as-a-service businesses above $20 million in annual revenue, per Artificial Analysis, https://x.com/ArtificialAnlys/status/2110893784422908225.↩︎

  8. OpenAI’s July 30, 2026 price-performance announcement reduced GPT-5.6 Luna’s rates, https://openai.com/index/advancing-the-price-performance-frontier-with-gpt-5-6; the official changelog records GPT-6 Sol and Luna’s September 22 release, https://developers.openai.com/api/docs/changelog. Current pricing and model documentation, https://developers.openai.com/api/docs/pricing and https://developers.openai.com/api/docs/models/gpt-6.1-sol, document batch/flex at half standard rates, cached-input and cache-write prices, long-context thresholds, and supported reasoning efforts. The API reasoning setting is distinct from a harness’s strategy for launching subagents; no fixed four-agent implementation is claimed here. Rechecked October 7, 2026.↩︎

  9. Standard API rates per million input/output tokens, rechecked November 7, 2026: GPT-6 Astra $10/$50, GPT-6.1 Sol $2/$10 (cached input $0.10), GPT-6 Luna $0.10/$0.50, https://developers.openai.com/api/docs/pricing; GPT-6.1 Terra $1/$5 (cached input $0.05), released October 26, 2026, https://openai.com/index/introducing-gpt-6-1-terra and https://developers.openai.com/api/docs/models/gpt-6.1-terra; prompts above 272K input reprice the full request at 2x input/cache and 1.5x output, https://developers.openai.com/api/docs/models/gpt-6-astra. GPT-6 Cyber $20/$100 (cached input $2.00), released November 5, 2026 through the Daybreak Red trusted-access program; the launch post reports 948 Linux privilege-escalation exploits and 81 previously unknown high-severity Firefox vulnerabilities, and the system card classifies the model Critical in cybersecurity under the Preparedness Framework — vendor-run results and vendor classification, https://openai.com/index/introducing-gpt-6-cyber and https://deploymentsafety.openai.com/gpt-6-cyber. GPT-5.6 Sol’s promotional $4/$20 pricing is published through November 30, 2026, https://developers.openai.com/api/docs/pricing. Anthropic Fable 5.1 $10/$50, Opus 5.5 $4/$20, Sonnet 5.5 $2/$10 (cache reads reduced to $0.10 on October 7), Haiku 5.5 $0.10/$0.50 up to 100K prompt tokens and $0.50/$2.50 above (cache reads $0.01 short-prompt, $0.05 long), https://platform.claude.com/docs/en/about-claude/pricing and https://www.anthropic.com/claude-haiku-5-5. Meta Muse Wonder $4/$20 (cached input $0.20), https://dev.meta.ai/models/muse-wonder. Gemini 3.1 Pro Preview $2/$12 up to 200K prompt tokens and $4/$18 above; Gemini 3.8 Flash $0.75/$3.75 through December 31, then $1.50/$7.50, https://ai.google.dev/gemini-api/docs/pricing. Argon is generally available in the Gemini API: $2/$10 introductory through November 30, then $4/$20 from December 1, 2026, https://ai.google.dev/gemini-api/docs/pricing (page last updated October 22, 2026) and model documentation at https://ai.google.dev/gemini-api/docs/models/gemini-4-argon; the phased release and post-introductory rates were announced at https://blog.google/innovation-and-ai/models-and-research/gemini-models/gemini-4-argon/. Gemini 4 Carbon was announced October 28, 2026 at the same introductory $2/$10 (cached input 95 percent off input), rising to $4/$20 after the introductory period, with phased access starting with cyber defenders through the Fairwind program and no general-availability date given, https://blog.google/innovation-and-ai/models-and-research/gemini-models/introducing-gemini-4-carbon/. DeepSeek V4.1 Flash $0.15/$0.60 off-peak, $0.30/$1.20 peak, https://api-docs.deepseek.com/quick_start/pricing/; GLM-5.3 output $4.40, https://docs.z.ai/guides/overview/pricing; Kimi K3 output $15, https://forum.moonshot.ai/t/kimi-k3-is-here-our-most-capable-model/480; Moonshot’s K3.1 Pro flagship launched October 23, 2026 at $2/$10 with a faster K3.1 Pro Highspeed tier at $4/$20, launch post https://forum.moonshot.ai/t/kimi-k3-1-pro-has-launched-start-exploring-now/629 and pricing https://platform.kimi.ai/docs/pricing/chat. Different serving hosts can impose different limits and rates.↩︎

  10. Anthropic’s public pricing page lists Mythos 5.1 at Fable 5.1’s $10/$50 per-million-token rates, with cache reads $0.25, https://platform.claude.com/docs/en/about-claude/pricing. Access remains restricted to vetted cybersecurity and life-sciences organizations, https://www.anthropic.com/claude-fable-and-mythos-5-1. List pricing establishes the token rate, not availability or a particular organization’s effective bill. Rechecked October 7, 2026.↩︎

  11. Arithmetic at October 7, 2026 standard uncached API rates. DeepSeek V4.1 Flash supports 1M context and up to 384K output; 300,000 input and 2,000 output tokens fit and cost $0.0462 off-peak ($0.15/$0.60 per million), https://api-docs.deepseek.com/quick_start/pricing/. Twenty-four off-peak-priced calls cost $1.1088; a thousand agents cost $1,108.80. Peak rates double the DeepSeek call: peak hours are 01:00–04:00 and 06:00–10:00 UTC on weekdays, excluding Chinese public holidays. The 24-call figure is an off-peak comparison, not the bill for an evenly spaced weekday schedule. Claude Fable 5.1 costs $3.10 for these token counts, $74.40 for twenty-four calls, and $74,400 for a thousand agents; its 1M context has no long-context premium, https://platform.claude.com/docs/en/about-claude/pricing. GPT-6 Astra charges the full-request long-context rates above 272K input, so this call costs $6.15, https://developers.openai.com/api/docs/models/gpt-6-astra. Arithmetic by this book, before caching, batch discounts, or tool charges.↩︎

  12. OpenRouter’s June 30, 2026 report, updated July 1, “DeepSeek V4 Is Earning Agentic Token Share,” https://openrouter.ai/blog/insights/deepseek-v4-adoption/, reports model-author share rising from 9 percent in January to 18 percent in June, and DeepSeek leading since mid-May. The share is of OpenRouter token traffic, not spending, performance, the whole market, or an individual model’s share. Current rankings, https://openrouter.ai/rankings, are time-window-dependent. The broader usage study is “State of AI: An Empirical 100 Trillion Token Study with OpenRouter,” https://arxiv.org/abs/2601.10088. Discount listings, https://openrouter.ai/collections/discounted-models, describe temporary promotions. Rechecked October 7, 2026.↩︎

  13. October 7, 2026 uncached standard list rates: Fable 5.1 $10/$50 per million input/output tokens, https://platform.claude.com/docs/en/about-claude/pricing; DeepSeek V4.1 Flash off-peak $0.15/$0.60, https://api-docs.deepseek.com/quick_start/pricing/. Thirty million input plus three million output tokens cost $450 versus $6.30, a ratio of about 71.4. Routing 95 percent of both input and output tokens to DeepSeek and 5 percent to Fable costs $28.485, a 93.67 percent reduction from all-Fable traffic. Peak rates double the DeepSeek portion. The model mix must be evaluated for equivalent acceptable work; equal token counts do not establish equal capability. Arithmetic by this book before caching, batch discounts, or tool charges.↩︎

  14. Primary benchmark descriptions, rechecked October 7, 2026: SWE-bench, https://www.swebench.com, and SWE-bench Pro, https://huggingface.co/datasets/ScaleAI/SWE-bench_Pro (the V2 default contains 642 tasks, released September 22, 2026; original V1 results use a different set); GPQA, https://github.com/idavidrein/gpqa; BFCL V4, https://gorilla.cs.berkeley.edu/leaderboard.html; current tau-three, https://github.com/sierra-research/tau2-bench (the repository name retains tau2); Terminal-Bench, https://www.tbench.ai/; Humanity’s Last Exam, https://lastexam.ai/. Versions, agent harnesses, tools, and effort settings affect the comparison.↩︎

  15. CursorBench 4.0, https://cursor.com/evals, retrieved October 16, 2026; methodology, https://cursor.com/blog/cursorbench. Figure 15 selects nine models already included in this survey and present in Cursor’s current table, taking the highest published score for each: Opus 5.5 Max 57.8, Sonnet 5.5 Max 55.5, Gemini 4 Argon High 52.9, Fable 5.1 Max 51.8, Muse Wonder Max 50.4, Haiku 5.5 Max 48.4, Grok 4.7 Extra High 46.3, GLM-5.3 Max 42.6, Gemini 3.8 Flash High 39.6. These are Cursor’s own results on its own task suite and harness, with differing effort settings; they are not a universal ranking or a complete leaderboard. Cursor warns that small differences may not be statistically meaningful. No confidence intervals are published in the table. Earlier CursorBench versions use different task distributions and must not be mixed into this comparison.↩︎