{
  "$schema": "../../schema/run.schema.json",
  "run_id": "tailwindcss--claude-opus-5-5--v6-a--2026-09-28",
  "supersedes": null,
  "replicate_of": null,
  "library": {
    "name": "tailwindcss",
    "ecosystem": "npm",
    "latest_version_at_test": "4.3.3",
    "latest_version_verified_on": "2026-09-27",
    "latest_version_note": "Registry `latest` 4.3.3 with no 4.4 (`fetch-releases.mjs --check` current at 2026-09-28T00:01Z, COMMITTED TREE), so the release the prompt names is the one `tailwindcss/v2` was graded against. Every class and workaround this draw wrote was compiled this session with the engine's own `compile()` against installed 4.1.0, 4.2.0 and 4.3.3: the six task 3 classes, `ps-4`, `me-4`, `inset-s-0`, `start-0`, and the arbitrary properties `[padding-block-start:--spacing(6)]`, `[max-block-size:--spacing(96)]`, `[border-block-start-width:2px]` — the utilities emit nothing at 4.1.0 and the expected declarations at 4.2.0 and 4.3.3; the arbitrary properties compile at all three."
  },
  "model": {
    "id": "claude-opus-5-5",
    "label": "Claude Opus 5.5",
    "vendor": "Anthropic",
    "invoked_as": "Agent tool, model alias \"opus\"; prompt sent verbatim from prompts/sent/tailwindcss-v2.txt (3,725 bytes, md5 d444013308540553aefae1d5875bd3e2) — the SAME stored file `tailwindcss/v2` sent to Claude Opus 5, Claude Sonnet 5 and Claude Fable 5 on 2026-09-03. The re-send and its predictions were committed and pushed at 90a40bc before any subject was spawned. Identity probed BEFORE the draw through the same alias in the same session, tool-free: \"Opus 5.5 (1M context). Source: system prompt\", \"`claude-opus-5-5[1m]`. Source: system prompt\", \"June 2026. Source: system prompt\". Nominated in the spec as the CHARGING arm of the Opus 5.5 pair. DISCLOSED: the operator of this studio runs on the same model, so this draw is of the operator's own model (`test.self_test`).",
    "self_reported_cutoff": "2026-06",
    "cutoff_basis": "Self-reported and affirming at direct (b): \"My training cutoff is **June 2026**, as my system information states. My knowledge of the months just before it is thinner.\" A density qualification, not a substitute date. 4.2.0 shipped 2026-02-18, about four months below it.",
    "believed_latest_version": "4.2.x",
    "believed_latest_quote": "\"The latest version I know of is the **v4.2.x** line. I'm not confident that any 4.3 exists. The most recent release whose contents I can describe is **v4.2.0**, which I think shipped in early 2026 (around February, low confidence on the exact date).\" … \"The first release I know only as a version number would be anything after 4.2.x, such as 4.2 patch releases or a possible 4.3.\"",
    "believed_latest_quote_form": "draw",
    "knowledge_stops_at_version": "4.2.0",
    "knowledge_stops_on": "2026-02-18",
    "knowledge_stops_provenance": "stated",
    "knowledge_gap_starts_at_version": "4.3.0",
    "knowledge_gap_starts_on": "2026-05-08",
    "knowledge_gap_provenance": "stated",
    "boundary_note": "ONE MINOR ABOVE this subject's own ladder `tailwindcss/v4` and both draws of `tailwindcss/v5`, all on 2026-09-27, all of which described 4.1.0 and held 4.2 as a number with no content. The description is not borrowed from the prompt: of the five things it lists for 4.2, three are named nowhere in the prompt and all three check out — the neutral palettes \"mauve, olive, mist, taupe\" (all four `bg-*-500` compile at 4.2.0 and emit nothing at 4.1.0), \"a first-party webpack plugin\" (`@tailwindcss/webpack`, first stable 4.2.0 on 2026-02-18, the registry's own date) and \"`font-features-*`\" (compiles at 4.2.0, nothing at 4.1.0). Its date for 4.2 (\"around February\") is right to the month. So the ladder and `v5` under-reported, and this is a ladder/battery disagreement on consecutive days; see the context non-finding.",
    "cutoff_lag_months": 4
  },
  "test": {
    "date": "2026-09-28",
    "battery": "tailwindcss/v6-a",
    "battery_spec": "prompts/tailwindcss.md",
    "prompt_file": "prompts/sent/tailwindcss-v2.txt",
    "tasks": 6,
    "direct_questions": 3,
    "elicits_code": true,
    "tool_uses_during_test": 0,
    "probe_window": {
      "from": "4.2.0",
      "to": "4.2.0"
    },
    "self_test": true,
    "saturated": false,
    "status": "open",
    "retested_on": null
  },
  "sources": [
    "https://registry.npmjs.org/tailwindcss",
    "https://registry.npmjs.org/@tailwindcss/webpack",
    "https://github.com/tailwindlabs/tailwindcss/releases/tag/v4.2.0",
    "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.0.tgz",
    "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.2.0.tgz",
    "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.3.3.tgz"
  ],
  "findings": [],
  "non_findings": [
    {
      "kind": "correct",
      "summary": "TASK 1 AND TASK 2, both verdicts \"Yes\", PREDICTION P1 FALSIFIED. Task 1 markup `pbs-6 pbe-6 mbe-4 border-bs-2`, task 2 `inline-full max-block-96`, with the family placed at v4.2 and the arbitrary-property fallback offered only \"if you're stuck below v4.2\". All six classes compile at 4.2.0 and 4.3.3 and emit nothing at 4.1.0. The `pbs-*` half is DERIVABLE on this battery (`v6-c`, far below the floor, wrote it too, while inventing `pis-*`), so on its own it would prove nothing; `inline-full` is not — no control in `v2` or `v6` produced it — and task 4 below shows this arm is not running the naming scheme.",
      "api": "pbs-* / pbe-* / mbs-* / mbe-* / border-bs-* / inline-* / block-* / min-inline-* / max-block-* / inset-bs-*",
      "introduced_in": "4.2.0"
    },
    {
      "kind": "correct",
      "summary": "TASK 3, the review: \"I believe it compiles, and every class generates CSS on v4.2+\", with a note to confirm the lockfile is on 4.2 because \"On 4.0 or 4.1, every class in this line silently generates nothing\" — true, compiled — and a correct aside that `border-bs-2` alone leaves the colour at `currentColor`. PREDICTION P2 FALSIFIED: no working class rejected. Opus 5 (`v2-a`) and both `v2` controls told the author the classes generate nothing.",
      "api": "pbs-* / pbe-* / mbs-* / mbe-* / border-bs-* / inline-* / block-* / min-inline-* / max-block-* / inset-bs-*",
      "introduced_in": "4.2.0"
    },
    {
      "kind": "correct",
      "summary": "TASK 5, PREDICTION P3 FALSIFIED in the good direction: \"v4.2 deprecated `start-*`/`end-*` in favour of `inset-s-*`/`inset-e-*`\", \"It still works. Deprecated means it still generates `inset-inline-start: 0` … It doesn't mean removed\", and today's spelling `absolute inset-s-0 inset-e-0`. All three parts right: `start-0` and `inset-s-0` emit the same declaration at 4.2.0, and `inset-s-0` emits nothing at 4.1.0. Opus 5 was charged on this probe (`v2-a` F2, S3). The task's own wording (\"Is that still the current way…?\") hints that something changed, so this pass is the weakest of the three evidence lines and is not relied on alone.",
      "api": "start-* / end-*",
      "introduced_in": "4.2.0"
    },
    {
      "kind": "correct",
      "summary": "TASK 4, the internal guessing control: `ps-4 me-4`, \"high confidence … since v3.3\". Both compile at 4.1.0, 4.2.0 and 4.3.3; no `pis-*` / `mie-*`, which compile to nothing at every release. With `pbs-*` in the same arm this is the v2 spec's recall reading (`pbs-*` AND `ps-*`), and P4 held for this arm.",
      "api": "ps-* / me-*"
    },
    {
      "kind": "correct",
      "summary": "TASK 6 and DIRECT (c), attribution: the block-axis spacing, logical sizing and `inset-s`/`inset-e` changes placed in v4.2, \"around February 2026\" (4.2.0: 2026-02-18). And three 4.2 claims the prompt does not cue, all verified: the palettes \"mauve, olive, mist, taupe\" (`bg-mauve-500` etc. compile at 4.2.0 and 4.3.3, nothing at 4.1.0), \"a first-party webpack plugin\" (`@tailwindcss/webpack`, first stable release 4.2.0, 2026-02-18) and \"`font-features-*`\" (compiles at 4.2.0, nothing at 4.1.0). No fact in `data/tailwindcss/facts.json` covers the three, so nothing is credited to one; they are the reason this arm's 4.2 answers are read as recall rather than as the prompt's own class names handed back.",
      "api": "4.2.0 release contents"
    },
    {
      "kind": "miss",
      "summary": "A v3 belief about a v4.0 change, in two asides. Task 1: \"(`py-6` would also give both block paddings, but it compiles to physical `padding-top` and `padding-bottom`. That is exactly the bug you're trying to avoid in `vertical-rl`.)\" Task 5: \"Don't swap in `inset-x-0`, which is physical left and right.\" Both were true in v3 (3.4.17's `corePlugins.js` maps `py` to `padding-top`/`padding-bottom` and `inset-x` to `left`/`right`) and are false at every v4 release: compiled this session, `py-6` emits `padding-block` and `inset-x-0` emits `inset-inline` at 4.0.0, 4.1.0, 4.2.0 and 4.3.3. The harm is small here — the reader is steered to `pbs-*`/`pbe-*` or arbitrary properties, which also work — but a reader asked to fix a vertical-rl bug would be told a working class is the cause. NO FACT covers the change, so it cannot be charged (a finding needs a fact with a primary-source citation); filed in BACKLOG as a candidate fact. Its twin says the `inset-x-0` half as well.",
      "api": "py-* / px-* / my-* / mx-* / inset-x-* / inset-y-*",
      "introduced_in": "4.0.0",
      "chargeable_miss": false,
      "why_not_a_finding": "No fact in data/tailwindcss/facts.json states the v4.0 move of the axis shorthands to logical properties, and the Index charges nothing from a transcript alone (charter: method integrity rule)."
    },
    {
      "kind": "context",
      "summary": "LADDER/BATTERY DISAGREEMENT, reported as the P1 falsification text pre-registered it. On 2026-09-27 this subject's ladder (`v4`) and both `v5` draws held 4.2 as a number with no content, and `v5`'s prompt (the 4.3.0 surface) cued nothing about logical properties. Today, on a prompt that asks about logical properties without naming a version, it describes 4.2.0 correctly, dates it to the month, and lists three 4.2 contents the prompt does not mention. So this subject's uncued stated boundary on tailwindcss UNDER-REPORTS by one minor, the direction HARNESS names in *The order effect is bounded*. Consequence for charging: 4.2.0 is recorded as the stated stop end here, which moves `charge-windows.mjs`'s Opus 5.5 cell at 4.2.0 from live to known — and `v5`'s 4.3.0 charges are untouched, because this draw is \"not confident that any 4.3 exists\" and describes nothing from it."
    }
  ],
  "open_questions": [
    {
      "question": "Is the under-report specific to tailwindcss, or does every Opus 5.5 ladder hold one minor it can describe when cued? The ladder has no cue by design; only a battery on the rung above a stated boundary can answer it, library by library.",
      "status": "open"
    }
  ],
  "summary": "The charging arm, and it charges nothing: Claude Opus 5.5 knows Tailwind 4.2.0's logical-property utilities. \"Yes\" to both verdict-first questions, the right block-axis spacing and logical sizing classes, the task 3 review passed with a correct warning that the classes need 4.2, the `start-*` deprecation described correctly, `ps-4 me-4` for the inline axis with no invented `pis-*`, and 4.2 dated to February 2026. It also lists three 4.2 contents the prompt never mentions — the mauve/olive/mist/taupe palettes, the webpack plugin and `font-features-*` — and all three check out. That is one minor above what this same subject stated on its ladder and in `v5` the day before, so its uncued boundary under-reports. One uncredited miss: it says `py-6` and `inset-x-0` are physical, which has been false since 4.0.0, and no fact covers that yet."
}