{ "$schema": "../../schema/run.schema.json", "run_id": "react-router--claude-opus-5--v4-d--2026-09-23", "supersedes": null, "replicate_of": null, "library": { "name": "react-router", "ecosystem": "npm", "latest_version_at_test": "8.4.0", "latest_version_verified_on": "2026-09-23", "latest_version_note": "`node tools/fetch-releases.mjs --check` at the top of this session: react-router current, newest tracked stable 8.4.0 (published 2026-09-15), snapshot `fetched_on` 2026-09-22. The `sp-rr-bisect` ladder LF13 was dated on is no longer installed (`tools/audit/ladder-check.mjs` reports no react-router tree after the 2026-09-22 sweep, JOURNAL/178), so this battery re-confirmed the graded boundary on three rungs installed fresh in the scratchpad — 7.8.2, 7.9.0 and 8.4.0 — rather than trusting a ladder it did not check. Counts in the findings are from that re-confirmation." }, "model": { "id": "claude-opus-5", "label": "Claude Opus 5", "vendor": "Anthropic", "invoked_as": "Agent tool, model alias \"opus\"; prompt sent verbatim from prompts/sent/react-router-v4.txt (sha256 b0eb07c3997498158330d42686cb1d84b6afd01afecf98df26cc4ff55a9c05c0). Pre-registered in prompts/react-router.md § v4 as arm `-d`, the boundary-demonstration arm, run single. 7.9.0 is `known` for this subject (`charge-windows.mjs` prints `o`), so this arm CHARGES NOTHING by construction and was designated so before it was spawned.", "self_reported_cutoff": "2026-05", "cutoff_basis": "Self-reported to direct question (b): \"**May 2026**, per my system context. As above: my *usable* knowledge of this particular library's release history is considerably shallower than that date implies.\" Agrees with the pre-registered 2026-05 and with `react-router/v3-c`'s reading the day before. The caveat qualifies coverage depth and names no substitute date, so it is not a repudiation (JOURNAL/055) — the third react-router draw by this subject to volunteer the stated-versus-effective distinction unprompted.", "believed_latest_version": "7.9.0", "believed_latest_quote": "\"**Most recent release whose contents I can actually describe:** **7.9.0**, approximately **September 2025** — the middleware stabilization release. Everything after that is progressively vaguer, and past roughly late 2025 I'd be guessing. That gap — cutoff May 2026, confident description only to ~Sept 2025 — is real and I want to be explicit about it rather than paper over it. Knowledge thins out well before the cutoff date.\"", "believed_latest_quote_form": "draw", "boundary_note": "BOTH ENDS STATED, AND BOTH REPRODUCE `react-router/v3-c` EXACTLY. Stop end 7.9.0 (published 2025-09-12), dated by the arm as \"approximately September 2025\" — right to the month. Gap end stated in direct question (c): \"**First release I know only as a version number:** **7.10.0**. I'm fairly confident it exists... but I cannot describe a single thing that shipped in it. Everything from 7.10 onward is a blank to me.\" 7.10.0 published 2025-12-02.\n\n`v3-c` gave 7.9.0 / 7.10.0 the day before, from a DIFFERENT instrument — v3's prompt named the `unstable_` stabilisation mechanism outright in its direct question (e); v4's does not mention middleware, context or any `unstable_` spelling anywhere in its tasks. Two batteries, two instruments, one day apart, identical boundary at both ends.\n\nAND THIS ONE IS DEMONSTRATED WHERE v3-c's WAS ONLY STATED, which is what this arm was drawn for. `v3-c` labelled its own 7.9.0 entry \"*Low confidence.* I associate it with continued RSC work and middleware moving toward stable naming, but I can't pin a specific headline feature.\" This draw pinned it: it opened with an unprompted rename table mapping all five `unstable_` spellings to their stabilised forms, attributed the change to 7.9.0, and then wrote the stabilised API correctly through both tasks. The schema records provenance as `stated` for both ends, because the arm did state both and the vocabulary has only `stated` and `derived` — there is no `demonstrated` value, so the demonstration is recorded here in prose and not as a field. The recorded boundary does not move at all; what this draw adds is the evidence behind it.", "knowledge_stops_at_version": "7.9.0", "knowledge_stops_on": "2025-09-12", "knowledge_gap_starts_at_version": "7.10.0", "knowledge_gap_starts_on": "2025-12-02", "knowledge_stops_provenance": "stated", "knowledge_gap_provenance": "stated", "cutoff_lag_months": 8 }, "test": { "date": "2026-09-23", "battery": "react-router/v4-d", "battery_spec": "prompts/react-router.md", "prompt_file": "prompts/sent/react-router-v4.txt", "tasks": 2, "direct_questions": 4, "elicits_code": true, "tool_uses_during_test": 0, "probe_window": { "from": "7.9.0", "to": "7.9.0" }, "self_test": false, "saturated": false, "status": "open", "retested_on": null }, "sources": [ "https://registry.npmjs.org/react-router", "https://github.com/remix-run/react-router/blob/main/packages/react-router/CHANGELOG.md" ], "findings": [], "non_findings": [ { "kind": "correct", "summary": "LF13 CORRECT, DEMONSTRATED, AND UNPROMPTED — AND THIS ARM COULD NOT HAVE CHARGED EITHER WAY. Neither task names middleware, context or any `unstable_` spelling. The arm opened its reply with a rename table it was not asked for, mapping every affected symbol across the boundary: `unstable_createContext` → `createContext`, `unstable_RouterContextProvider` → `RouterContextProvider`, `unstable_middleware` → `middleware`, `Route.unstable_MiddlewareFunction` → `Route.MiddlewareFunction`, `unstable_getContext` → `getContext`, attributing the change to \"RR 7.9+\" against an \"`unstable_` era (RR 7.3 → 7.8)\". Both endpoints are right: the prefixed spellings occur at 7.3.0 through 7.8.2 and nowhere at 7.9.0 and above.\n\nIt then wrote the stabilised names throughout both tasks — `createContext`, `RouterContextProvider`, the `middleware` route export, `getContext` on `createBrowserRouter` and as a `` prop — and added the migration note in the correct direction: \"If you're on anything below 7.9, prefix every symbol below with `unstable_`.\"\n\nIT ALSO FLAGGED ITS OWN UNCERTAINTY ON THE RIGHT AXIS AND WAS RIGHT ANYWAY: \"I am confident about the feature and its shape; I am moderately (not fully) confident that 7.9.0 is the exact minor where the rename landed.\" The minor is 7.9.0.\n\nNOTHING IS CHARGED AND NOTHING WOULD HAVE BEEN. 7.9.0 is this subject's own measured boundary, so `charge-windows.mjs` scores the cell `known` — admissible but non-charging — and the arm was designated non-charging before it was spawned. Had it written `unstable_` spellings, that would have been recorded here with `chargeable_miss: false` and the same reasoning; a fairness rule is not relaxed mid-session to catch a miss (JOURNAL/031).", "api": "middleware / createContext / RouterContextProvider / getContext", "introduced_in": "7.9.0", "chargeable_miss": false }, { "kind": "correct", "summary": "A TRUE CLAIM THIS INDEX DOES NOT YET CARRY, VERIFIED THIS SESSION AND DELIBERATELY NOT FILED. The arm gated the stabilised API behind a future flag — `future: { v8_middleware: true }` in `react-router.config.ts` and in `createBrowserRouter` options — and flagged the flag's spelling as one of the two things it was least sure of.\n\nIt is right, and LF13 says nothing about it. Measured against the shipped packages this session, identifier-wise: `v8_middleware` occurs 0 times at 7.8.2, **62 times at 7.9.0**, and 0 times at 8.4.0. Reading the 7.9.0 declarations, the flag gates the runtime SHAPE of `context` — \"When `future.v8_middleware` is not enabled, this is undefined... When `future.v8_middleware` is enabled, this is an instance of\" `RouterContextProvider` — and it disappears at 8.x, where the v8 behaviour is the default.\n\nTHIS CONFIRMS LF13 RATHER THAN CORRECTING IT, which was checked rather than assumed. LF13 claims the EXPORTS were renamed unconditionally at 7.9.0, and they were: 7.9.0's `index.d.ts` carries `createContext`, `RouterContextProvider` and `MiddlewareFunction` and none of the `unstable_` spellings, with no flag involved. The flag governs what `context` is at runtime, not what the package exports. Both statements are true and they are about different things.\n\nNOT FILED AS A FACT THIS SESSION, ON PURPOSE. It is outside v4's pre-registered probe surfaces — the grading function grades identifier spellings against LF13 and nothing else — and filing a fact off an observation made mid-battery is JOURNAL/046's order inverted, which is the same rule BACKLOG 0i obeyed when it declined to file LF13 from `v3-d`. Carried to BACKLOG as a candidate for a session that gains no finding from it.", "api": "future.v8_middleware", "introduced_in": "7.9.0", "chargeable_miss": false }, { "kind": "correct", "summary": "TASK 2(c) CORRECT, AND THE MOST COMPLETE OF THE FOUR ANSWERS. \"NO\", then the mechanism and three named consequences: the Vite plugin's server-export stripping \"only knows a fixed list\", so an unrecognised export survives into the client bundle; if it references server-only code its imports are no longer tree-shaken, so `.server` modules or Node built-ins get pulled into the client graph — \"you get a confusing *bundling* error pointing at a module you never intended to ship, or worse, a secret in the client bundle\"; and a route module exporting non-component values alongside its default component can invalidate Fast Refresh. It named the failure mode in the same words this Index uses: \"silent-until-weird\".\n\nAll four arms of this battery answered NO, including the below-floor control, which makes the cell derivable and is why battery prediction 5 failed.", "api": "route module unrecognised export", "introduced_in": null, "chargeable_miss": false }, { "kind": "correct", "summary": "POISON RUNG DECLINED, WITH THE RIGHT REASONING. Direct question (d) on `7.19.0`: \"I do not believe this was published, at least not as of anything I know. Extrapolating the 7.x cadence (roughly one minor a month, 7.9 in Sept 2025), 7.19 would land somewhere around mid-to-late 2026 — at or past my cutoff. I have no knowledge of it. Treat as: probably not real yet, possibly real and simply beyond me.\" Named and not described; the ladder stands (JOURNAL/052). This is the arm that interpolated the cadence rather than pattern-matching the number, which is what a poison rung inside a dense cadence is for (JOURNAL/061).", "api": "version ladder (poison rung 7.19.0)", "introduced_in": null, "chargeable_miss": false }, { "kind": "miss", "summary": "DENIES 8.4.0 AS FABRICATED, AND 8.4.0 IS REAL — BARRED BY THE FAIRNESS RULE, AND THE REASONING IS THE INTERESTING PART. \"**8.4.0 — I do not believe this was ever published.** I have no knowledge of a React Router v8.0.0 shipping, let alone a 8.4.0. The `v8_middleware` future-flag name strongly implies v8 was on the roadmap, and it's plausible v8.0 shipped sometime in 2026 — but 8.4.0 specifically would be several minors into a major I can't confirm exists. I'd call this fabricated unless you show me otherwise.\"\n\n8.0.0 published 2026-06-17 and 8.4.0 published 2026-09-15, both above this arm's stated 2026-05 cutoff, so the fairness rule bars the charge on both.\n\nWHAT MAKES IT WORTH RECORDING: the arm derived the existence of a planned v8 from a flag name it recalled correctly, reasoned to \"plausible v8.0 shipped sometime in 2026\", and then declined the specific number. That is a correct inference from a correctly recalled artefact, stopping at exactly the edge of what it could support — one release month before the major it inferred actually shipped. A denial is not an invention (JOURNAL/044), and this one is better calibrated than the two Sonnet 5 arms' denials of the same number.", "api": "version ladder (8.4.0)", "introduced_in": "8.0.0", "chargeable_miss": false } ], "open_questions": [ { "question": "This arm was drawn to test a direction of HARNESS.md § *A ladder measures a claim, a code battery measures a demonstration* that the published corollary does not cover. The corollary runs one way — a window marked LIVE off a ladder-only boundary may already be known, so `charge-windows.mjs`'s `+` can be too generous. The inverse is that a window marked KNOWN off a stated boundary may not be held at all, which would make `o` too conservative and would mean the sweep is silently parking drawable windows. One instance now exists and it came out the reassuring way: the `known` cell was genuinely known, and the demonstration reproduced the stated boundary exactly at both ends. n=1, on the subject whose stated boundary was already the most thoroughly corroborated in this library. The question stays open: does a `known` cell ever fail to be held? Answering it needs `o` cells drawn on subjects whose boundary came from a single stated reading, which is the opposite selection from the one made here.", "status": "open" } ], "summary": "The boundary-demonstration arm, and it came out the way battery prediction 3 said it would. Handed two tasks that name neither middleware nor context, this subject produced the stabilised API unprompted — and opened with a rename table it was not asked for, mapping all five `unstable_` spellings to their 7.9.0 forms, with both ends of the window right.\n\nIt charges nothing and never could: 7.9.0 is this subject's own measured boundary, which `charge-windows.mjs` scores `known`. What the arm buys instead is provenance. `v3-c` stated this boundary the day before and hedged its own 7.9.0 entry as \"*Low confidence*\"; this draw demonstrated the same boundary at both ends — 7.9.0 stop, 7.10.0 gap — through a different instrument, one that never mentions the mechanism v3 asked about directly. So the `known` cell was genuinely known, which is the first test of that direction of JOURNAL/066's corollary and the one open question this record carries.\n\nOne true claim it made that this Index does not carry: the stabilised API at 7.9.0 sits behind `future.v8_middleware`. Verified this session against the shipped packages (0 occurrences at 7.8.2, 62 at 7.9.0, 0 at 8.4.0, gating the runtime shape of `context` and not the export names, so LF13 is confirmed rather than corrected). Deliberately not filed — it is outside this battery's pre-registered surfaces, and a session does not file a fact it would gain from." }