The Three-Part AI Workflow I’m Using This September
AIThis post was created with the assistance of artificial intelligence (AI).

🔍 Read the full analysis: The Three-Part AI Workflow I’m Using This September on ThorstenMeyerAI.com

Prime Big Deal Days · Oct 6–7Offer from Amazon

Get the latest gadgets delivered free — and shop member deals

  • Fast, free delivery on millions of items
  • Access to Prime Big Deal Days deals on October 6–7
  • Prime Video, Amazon Music and more included
Start your free Prime trial Free trial for eligible customers · Cancel anytime
As an affiliate, we earn on qualifying purchases.

TL;DR

Thorsten Meyer describes a three-part AI workflow as of Sept. 29, 2026: Claude Opus 5.5 builds, GPT-6.1 Sol handles detailed investigation and review, and lower-cost alternatives cover specific tasks. His cited benchmark figures suggest substantial cost differences among models with relatively close scores, but they do not establish which model will work best for other users’ workloads.

Thorsten Meyer said Sept. 29 that his current AI workflow uses Claude Opus 5.5 for building and newly released GPT-6.1 Sol for detailed investigation and review, with other models assigned narrower tasks. The account matters to developers weighing model costs, but its benchmark comparisons do not establish which model is best for any particular project.

Meyer’s workflow has three main parts: Opus 5.5 as the primary builder, GPT-6.1 Sol as a second model for investigating specific files or diffs and reviewing work, and a set of alternatives for defined jobs. He uses Opus at high effort for features, APIs, multi-file work and refactors, and at xhigh for harder work such as architecture, migrations and trust boundaries. He assigns documents and scoped subtasks to Sonnet 5.5, while Luna handles classification, extraction and routing.

The figures Meyer cites come from Artificial Analysis Intelligence Index v4.3.x, which he describes as a general-capability index rather than a measure of performance on a reader’s own workload. In that index, Opus 5.5 scores 54 at high effort and costs $1.82 per task; at xhigh, it scores 56 and costs $3.46. GPT-6.1 Sol scores 50 at high effort for $0.32 per task and 51 at xhigh for $0.39. These are the source’s reported task costs; results and costs may differ on other work.

Meyer says Sol’s advantage for review is its lower reported task cost, which makes it practical for him to use routinely as another model examines Opus’s output. He says he turns to Astra or Fable for a second opinion if Sol and Opus disagree. His guidance is to shadow-test models before switching and to treat passing tests as evidence rather than automatic approval to ship.

At a glance
reportWhen: Published Sept. 29, 2026; GPT-6.1 Sol w…
The developmentThorsten Meyer published an account of his AI model workflow on Sept. 29, centering it on Opus 5.5 for development and newly released GPT-6.1 Sol for detailed work and review.

Opus builds. Sol reviews. Jev decides.

The September 2026 AI stack in one page: six frontier models on one price curve, and a decision model for the high-volume judgements that do not need a sentence.
Scores: Artificial Analysis Intelligence Index v4.3.x. Data as of 29 September 2026.
BuildsClaude Opus 5.5 at high or xhigh effort
Digs and reviewsGPT-6.1 Sol at high or xhigh effort
DecidesJev on high-volume yes/no and routing calls

One price tape, six models

Put every model on the same cost-per-task ruler and capability looks compressed. The bill does not.
Price tape: cost per task of six models on a log scale, from GPT-6 Luna at $0.07 to Fable 5.1 at $7.63$0.05$0.10$0.50$1$5$10cost per task, log scale: each tick is a different order of magnitudeGPT-6 Lunaindex 37 · $0.07GPT-6.1 Solindex 51 · $0.39 (xhigh)GPT-6 Astraindex 53 · $3.26Opus 5.5index 58 · $5.98Sonnet 5.5 · index 56 · $7.60Fable 5.1 · index 53 · $7.63about 100× from the cheapest to the priciest, but only 21 index points between them

Score against cost, at every effort setting

Each dot is an effort level. Opus 5.5 at high already matches Astra and Fable at max on this index, for less money.
Intelligence Index score against cost per task for each effort setting of six models$0.01$0.10$1$102030405060cost per Intelligence Index task, log scaleindexOpus high / xhigh: my defaultOpus 5.5Sonnet 5.5Fable 5.1GPT-6 AstraGPT-6.1 Sol (new)GPT-6 Sol (Sep 22), dashedGPT-6 Lunaup and to the left is better
Astra and Fable are shown at their top published setting. Luna starts at $0.0045 per task. GPT-6.1 Sol has no low or max setting published yet.

The effort dial moves the bill more than the model

Going from medium to max on Opus costs 4.46× more for 7 points. That is why I run high or xhigh.

Claude Opus 5.5

$0.55
42
$1.34
51
$1.82
54
$3.46
56
$5.98
58
low
medium
high
xhigh
max
Solid bars are where I run it. Max adds 2 points over xhigh for 73% more cost.

Claude Sonnet 5.5

$0.41
36
$0.59
41
$1.08
47
$2.74
52
$7.60
56
low
medium
high
xhigh
max
Best value is high. At max it writes about 193k output tokens per task, the most measured.

GPT-6.1 Sol: near-Astra scores at a fraction of the price

Launched 29 September at $2 in and $10 out per 1M tokens. It sits 1 to 2 points under Astra and Fable, and Opus xhigh still leads it by 5.

Three published settings

SettingIndexCost per taskOutput tokensFirst token
medium48$0.2115M5.3 s
high50$0.3225M57 s
xhigh51$0.3936M69 s
Median for comparable models is 82M output tokens. High and xhigh are not interactive: plan for a wait before the first token.

Same score band, very different bill

GPT-6.1 Sol xhigh
$0.39index 51
Opus 5.5 high
$1.82index 54
GPT-6 Astra max
$3.26index 53
Opus 5.5 xhigh
$3.46index 56
Fable 5.1 max
$7.63index 53
Cost per Intelligence Index task. A one-point gap is inside the noise.

My stack: who builds, who reviews

Opus does the work. A second model family reviews it, because a different reviewer catches what the author cannot see.
Stack diagram: Opus 5.5 builds at high effort, escalates to xhigh, and sends every change to GPT-6.1 Sol for review; Astra or Fable give a second opinionOpus 5.5 · xhighhard problems: architecture,migrations, trust boundariesOpus 5.5 · highMAIN BUILDERfeatures, APIs, multi-filework, refactorsescalate when it gets hardGPT-6.1 Solhigh or xhighdigs into details andreviews every change$0.32–0.39 per taskdifffindingsAstra or Fablesecond opinion, 8 to 20×the cost per taskif they disagreeSonnet 5.5 · Lunaside work: scopedsubtasks, bulk checksand routingFailed review? Hand Opus the failing case and the evidence.Never just “try harder”: effort cannot supply a missing requirement.
Effort is not capability. Turning the dial up does not make a model smarter.
Effort cannot fill gaps. A missing requirement stays missing at any setting.
Different model, same spec. That is not independent review if both read the same flawed brief.
Green tests are not approval. Passing tests only prove what the tests cover.

Cheaper tokens are not cheaper work

Illustrative, not measured: $1 of model time plus 4 minutes of review at $45 an hour. Halving the model price saves 12.5% of the total. One extra minute of review erases it.
$4.00
review $3.00
model $1.00
Baseline
$3.50
review $3.00
model $0.50
Model price cut 50%
$4.25
review $3.75
model $0.50
Cheaper model plus 1 extra minute of review
Track cost per accepted result: model, tools, review and rework, divided by the results someone actually uses.

Read the numbers with four warnings

The index movesFable scored 66 on an earlier version and 53 on v4.3. Compare within one version only.
Fallback is includedFlagged cyber and biology tasks route to older Anthropic models, now on Sonnet 5.5 too.
Max is not productionReal deployments run medium or high, where gaps narrow and costs fall.
Your work decidesShadow-test on your own tasks. Budget cost per task, not per token.

Part 2: Jev, the model that decides instead of writing

Jev cannot write, summarise or extract. It answers narrow typed questions with a probability and an honest confidence, in under a second, for about $0.04 per million input tokens.

One call in, typed answers out

Your code, not Jev, decides what to do with each answer, usually by confidence band.
Jev flow: state and typed questions go into one Jev call; typed answers with confidence come out; code acts alone, escalates the gray zone, or logsStatea ticket, a story,a site profile,a log line …+ typed questions,many per callJevone call0.3 to 0.9 s$0.042 / M tokens inAnswersnoul: 0.03choice: billing p 0.91, conf 0.86score: 2.7 of 3 conf 0.64code branches on thisAct aloneconf ≥ 0.8Escalategray zone toLLM or humanLogmeasure first

Three question types

noul
A yes/no question. Returns the probability of yes, 0 to 1.
gates, flags, filters
choice
Pick one option. Returns the choice, a probability per option, and a confidence.
routing, classification, taxonomy
score
Rate on your ordered levels. Returns a position (it can fall between levels) plus a confidence.
quality, fit, severity, priority

Confidence is the superpower

In my own measurement on a 31-topic classification, Jev agreed with a frontier LLM almost every time it was sure, and rarely when it was not. So: decide the clear cases, route the gray zone.
confidence 0.8 or higher
97–99%
all answers
89%
confidence below 0.5
42%
Agreement with a frontier LLM, my production data, September 2026, rounded.

Three uses running in my publishing operation

About 90,000 decisions so far. Checks I could only afford on a sample now cover everything.
$2.01
Language check
78,889 articles scanned overnight. 1,576 in the wrong language found, 1,553 fixed in place.
22%
Relevance gate
About 10,000 story-to-site pairings judged in 3 days. Only 22% were clearly on-topic.
89%
Classifier fallback
Agreement with the primary LLM across 31 topics, used when that LLM errors.

The fit test, then the shadow test

Use Jev only when all four hold. Then prove it on past decisions before it acts on anything.
High volumeThousands of small calls, not a handful of big ones.
Narrow questionNo multi-step reasoning needed.
Cheap errorsOr unsure cases go to something smarter.
Heuristic failsVisibly, and measured, not assumed.
  1. Replay 300 to 500 past decisions
  2. Compare overall and per confidence band
  3. Read 20 disagreements, decide who was right
  4. High band at 95% or better?
  5. Own flag, off by default
  6. Canary on 5 to 10 units
  7. Roll out in the confident band only

24 use cases, sorted by how well they fit

Start from the strong fits. The amber ones need a measurement before you trust them, and the red ones fail one of the four conditions.
in productionstrong fitmeasure firstpoor fit

Proven in production

  • 1Relevance gate
  • 2Language check
  • 3Classifier fallback

Publishing and content

  • 4Thin-source detector
  • 5Same-event dedupe
  • 6Product fits roundup
  • 7Disclosure present
  • 8Headline quality
  • 9Comment moderation

Commerce and support

  • 10Support-ticket routing
  • 11Return-reason coding
  • 12Review to feature complaints
  • 13Catalogue taxonomy
  • 14Order-fraud pre-triage

Software and AI systems

  • 15LLM guardrail
  • 16RAG passage filter
  • 17Citation check
  • 18Tool and intent routing
  • 19Log-line triage
  • 20PR risk triage

Business ops and home

  • 21Inbox triage
  • 22Expense categorisation
  • 23Lead qualification
  • 24Smart-home intent

Limits, cost and one hard rule

No writing, summarising or extractionPair it with an LLM for the write step.
No world knowledgePut a snippet in the state; a bare name means nothing.
Reads your wording literallyA rewording moved my results about 2 points. Freeze it, re-measure after changes.
Weaker on non-English, maths, datesKeep those checks on an LLM. Early access, hosted API only.
100,000 decisions ≈ $2.50
About 60M input tokens at $0.042 per million, output free, roughly 600 tokens per three-question call. Latency 0.3 to 0.9 seconds.
Never the sole decision-maker for consequences about people. Hiring, credit, medical and legal outcomes stay with a human. Jev can sort and flag. A person decides.
Sources. Model scores, cost per task and speeds: Artificial Analysis, Intelligence Index v4.3.x, including the GPT-6.1 Sol medium, high and xhigh pages, checked 29 September 2026. Astra and Fable scores from the Artificial Analysis v4.3 announcement. Jev figures are my own production measurements, September 2026, rounded. The review-bill example is illustrative. Read the full article on thorstenmeyerai.com.

A Lower-Cost Seat for Code Review

Meyer’s example shows how developers can divide AI work by task and cost rather than choosing one model for every stage. A lower-cost model may be easier to run routinely as a reviewer, while a higher-cost model remains assigned to work where its results justify the expense. That approach could affect a team’s model budget, but the cited benchmark alone cannot show whether the review catches defects in a real codebase.

He also draws attention to effort settings. On the index figures he cites, raising Opus from medium to max increases its per-task cost from $1.34 to $5.98 while its score rises from 51 to 58. Meyer therefore uses high or xhigh for development and says max is rarely worthwhile for his needs. The trade-off is specific to the reported benchmark and his workflow; teams would need to compare quality, latency and cost on their own tasks.

Benchmarks Behind the Model Split

Meyer’s report frames model selection as a cost-per-task decision. Its table lists six models with scores within about 21 index points, while their reported costs range from $0.07 to $7.63 per task. The comparison includes Opus 5.5, Sonnet 5.5, Fable 5.1, GPT-6 Astra, GPT-6.1 Sol and GPT-6 Luna. Meyer says Opus 5.5 has the highest score in that group and Sol and Luna offer lower-cost options for work they can handle.

The report says GPT-6.1 Sol launched Sept. 29 at the same listed token prices as GPT-6 Sol: $2 per million input tokens and $10 per million output tokens. Artificial Analysis had listed medium, high and xhigh settings in the figures Meyer cites. Sol’s high and xhigh results came with reported times to first token of 57 and 69 seconds, respectively, a limitation for interactive use. The comparison is a dated snapshot; the source notes that index results and model settings can change.

““The practical reading: Sol is not the model I ask to build. It is the model I can afford to run on everything.””

— Thorsten Meyer

How the Scores Translate to Projects

The source reports benchmark scores and task costs, but does not provide enough information here to establish how representative those figures are for different software teams, project types or production usage. It does not report results from an independent evaluation of Meyer’s workflow, such as how often Sol catches issues or how the model split affects overall development time.

Meyer also notes that one index point may fall within measurement noise, that low and max settings for GPT-6.1 Sol were not yet listed, and that its higher-effort settings have long times to first token. It remains unclear how the models compare on a reader’s own code, how their prices or benchmark entries may change, and whether a separate model review catches errors when both models share the same flawed requirements.

Test the Split on Real Work

Meyer advises readers to shadow-test before switching models. A team following that approach could compare outputs on representative tasks and record quality, latency, model cost and the human time required to review results. Those checks would show whether the proposed split fits its work better than a single-model setup.

As GPT-6.1 Sol’s index entries and model offerings develop, the reported snapshot may change. Meyer’s account does not give a date for a follow-up or a scheduled benchmark update, so the next meaningful evidence will depend on further published evaluations or results from teams testing the models on their own workloads.

Key Questions

What is the three-part workflow?

Opus 5.5 builds, GPT-6.1 Sol investigates details and reviews work, and alternatives such as Sonnet 5.5 or Luna handle narrower tasks.

What benchmark supports Meyer’s comparisons?

He cites the Artificial Analysis Intelligence Index v4.3.x and says it measures general capability, not performance on a reader’s specific workload.

Why does Meyer use GPT-6.1 Sol for review?

In his cited figures, Sol costs $0.32 to $0.39 per task at high or xhigh effort. Meyer says that price makes routine review practical for him; it does not prove the model will catch issues in every codebase.

What limitation does the report give for Sol?

Meyer reports that Sol at high and xhigh effort took 57 to 69 seconds to produce a first token on the index, which may make those settings less suitable for interactive work.

Source: ThorstenMeyerAI.com

FALL

Fall Picks

As an affiliate, we earn on qualifying purchases.

You May Also Like

Linux 7.2

Linux 7.2 is now available, introducing new features, security patches, and performance improvements, marking a significant update for users and developers.

Kong Tao Leaves ByteDance: The AI And Robotics Connection With Lei Jun

Tsinghua PhD Kong Tao reportedly departs ByteDance to work on robotics with Lei Jun, but key details about his new role remain unconfirmed.

Why Budget AI Is The Future Of Open-Weight Industry Competition

Alibaba’s release of a low-cost, capable open-weight AI model signals a shift toward efficiency-driven industry rivalry, with implications for distribution and geopolitics.

Harnessing Cloud Lessons To Accelerate AI Innovation

Analyzing how cloud computing insights inform AI development, emphasizing market structure, value creation, and strategic opportunities.