A community rumor — originating in X posts and relayed on r/ClaudeAI — holds that Anthropic is silently routing some Claude 'Fable 5.1' sessions to an unreleased 'Fable 5.5' ahead of any announcement, evidenced only by users' animation demos, subjective quality impressions, and a folk knowledge-probe ('do you know Tibo the reset guy? don't search'). The pattern recycles a prior-cycle ritual: the same probe was credited with detecting stealth routing to Opus 5.5 and Sonnet 5.5, and Opus 5.5 did launch Sept 22, 2026 after reportedly being stealth-tested under the codename claude-wafer-eap (TestingCatalog) — that precedent is what keeps the Fable rumor alive. But for Fable 5.5 everything remains testimony: no first-party '< routed from fable 5.1 >' artifact exists, Anthropic has not commented, the leaked name has flip-flopped (the original Sept 18 Chetaslua artifact said 'Fable 5.2', current posts say 5.5), Salio's docs-appearance claim ships no artifact, and the threads themselves carry counters ('the Fable 5.1 model has always known who Tibo is'). Snippets don't establish whether Sonnet 5.5 has actually launched (one post's 'sonnet 5.5 this week' is unconfirmed), and the rumor's own on/off arc — routing reportedly stopped then resumed — is equally consistent with placebo-plus-priming as with stealth A/B.
Scott's canon already holds everything this unresolved rumor could assert: dev:concept.owned-output-model-levels carries the absent-never-substituted doctrine and his LiteLLM/Anthropic pages carry the claim that config pinning cannot detect upstream first-party substitution — so an all-testimony, zero-first-party-artifact rumor with a non-discriminative canary and a placebo-consistent withdrawal arc confirms nothing and challenges nothing, merely re-enacting the evidence-ceiling epistemics (discussed-is-not-deployed) he already argues by; LOW because it illustrates his patterns without bearing on them. It re-classes to converges — dated receipts for the doctrine — only on a resolution trigger: Anthropic announcement/denial, a first-party '< routed from fable 5.1 >' artifact, credible failed replication, or a Sonnet/Haiku 5.5 launch the rumor fails to attach to.
dev:concept.owned-output-model-levelsdev:technology.litellmdev:technology.anthropicradar:openai-astra-silent-rerouting-claimradar:one-token-api-model-fingerprintingradar:concept.model-identityradar:concept.model-fingerprintingradar:anthropic-sonnet-5-5-releaseradar:concept.anthropic
queries asked of Scott's wikis
- absent never substituted silent model replacement doctrine
- behavioral fingerprinting LLM identity detection
- LiteLLM config pinning upstream model version drift
- knowledge cutoff canary non-discriminative probe epistemics
- stealth A/B testing frontier lab release detection methods
- Anthropic model release cadence Claude version pinning
now 0 pts/hpeak 151 pts/hcomments 3/hpeers p62momentum: steady2 platformsage 230h
points/hour across evidence · reading as of 2026-10-12 02:59:37.977291+11:00 · deterministic, not a model opinion
2026-10-11T12:28:48Z
New withdrawal report (1x35tt5) adds another claimant to the on/off arc — routing reportedly stopped ~3 days before expected launch — but it remains testimony in the same community ritual with zero first-party artifacts, a non-discriminative canary, and a placebo-consistent alternative. The discriminative gap is unchanged.
2026-10-11T11:36:50Z
evidence attached: reddit.post.1x35tt5 — User reports Fable 5.5 stopped routing in Claude Code ~3 days before expected launch, directly corroborating the silent-routing hypothesis.
2026-10-07T04:49:43Z
grounded: known/low — Scott's canon already holds everything this unresolved rumor could assert: dev:concept.owned-output-model-levels carries the absent-never-substituted doctrine a
2026-10-07T04:39:58Z
First post-decay addition (1wzj6d9) is a new claimant reporting the shadow-served model was pulled — an on/off arc that fits stealth A/B but equally fits the placebo-plus-priming cycle; the mod-side megathread funneling and a commenter's precedent (identical ritual around Opus 5.x months ago) tip the reading further toward recurring community lore each model cycle rather than accumulating evidence. Still zero first-party routing artifacts and no official word, so the case's meaning is unchanged: a rumor-watch with a discriminative gap.
2026-10-07T03:33:13Z
evidence attached: reddit.post.1wzj6d9 — User-side report with before/after screenshots that the shadow-served Fable 5.5 was pulled corroborates the silent-routing then withdrawal pattern at the heart of the case.
2026-10-05T21:58:01Z
The 1wyfrxv attach is derivative speculation, not corroboration: a 2-point post reading an unexplained CLI feature through six-month-old April-fools /buddy rumors — if anything it documents the community's priming habit (any unexplained Anthropic behavior gets labeled secret Fable testing), the same confounder that makes the 'Tibo' canary non-discriminative. With the second wave fully decayed (134.5 → 0.33 pts/h, 50th percentile, no new platforms or communities), the magnitude-valve flag prices the already-seen peak rather than current spread, so heat stays low and the case remains a rumor-watch pending official word, a first-party artifact, or a Sonnet/Haiku 5.5 launch the rumor fails to attach to.
2026-10-05T20:39:22Z
evidence attached: reddit.post.1wyfrxv — New unexplained CLI feature with /buddy-was-Fable-testing speculation feeds directly into the silent-Fable-5.5-routing case's resolution conditions.
2026-10-03T19:01:50Z
The 'second independent user report' attach (reddit.1wwtk57) is a mislabel — it relays the same Ishu Agrawal X demo already captured via 1wwbel8, so the claim still rests on one rumor lineage at artifact level with zero first-party '< routed from fable 5.1 >' artifacts. The second wave has fully decayed (0.67 pts/h, 22nd percentile, periphery static at 2 platforms) and the magnitude-valve reading reflects the already-priced peak rather than current spread, so heat drops to low while the case stays a rumor-watch pending official word, a first-party artifact, or a launch the rumor fails to attach to.
2026-10-03T18:25:45Z
evidence attached: reddit.post.1wwtk57 — Second independent user report of Fable 5.5 early access/A-B rollout corroborates the silent-routing sightings.
2026-10-03T05:33:09Z
The 'independent corroboration' attach was mislabeled: reddit.1wwbel8 is by the same author as the anchor thread (Successful-Earth678) relaying a second X demo (Ishu Agrawal), so the case still rests on a single rumor lineage with zero first-party routing artifacts. The second attention wave has crested (~123 pts/h peak down to ~4 pts/h, 58th percentile, cooling) and the periphery is no longer expanding (same two platforms, no new communities or outlets), so the high heat that priced that spread comes down to medium.
2026-10-03T02:25:11Z
evidence attached: reddit.post.1wwbel8 — Independent corroboration: a second community report of users being rerouted to unreleased Fable 5.5, exactly what the open case is watching to replicate.
2026-10-02T16:56:15Z
The rumor has mutated from one claimant's artifact into a community ritual: a third derivative post applies the 'Tibo the reset guy' canary as a routing test and a commenter defends it with claimed multi-account/platform testing — all still downstream of one contested folk probe, with zero first-party '< routed from fable 5.1 >' artifacts and no Anthropic word. Attention re-accelerated into a second wave (33.5 pts/h at 15h, 96th percentile, fresh 34.5x velocity spike on the relay thread, magnitude-valve spread) after the last look's cooling call, so heat goes high on spread and surface area for resolution evidence — not on any new substance; even a working canary would only show newer knowledge, which a silent 5.1 knowledge refresh would equally explain, so it is not discriminative for substitution.
2026-10-02T16:26:23Z
evidence attached: reddit.post.1wvxawd — User reports a community canary ('Tibo the reset guy') for Fable 5.5 routing and claims his Fable 5.1 session passed it — additional Reddit-side evidence for the silent-routing case.
2026-10-02T12:59:49Z
Meaning shift: the claim is no longer one claimant's artifact but a community-circulating rumor — a second Reddit thread spreads it with a folk probe ('do you know Tibo the reset guy?') that its own comments show is non-discriminating (Opus 5.5 answers plausibly). Substance is unchanged: still zero first-party replication of a '< routed from fable 5.1 >' artifact and Anthropic silence, so the delta is spread, not confirmation; attention peaked (~45 pts/h) and is cooling (~14 pts/h), which is why this stays medium rather than high despite the magnitude-valve spread reading and 98th-percentile rate.
2026-10-02T12:24:52Z
evidence attached: reddit.post.1wvr9xk — Independent Reddit-side spread of the silent Fable 5.5 routing reports with a replication prompt — corroborating evidence for the open case.
2026-10-02T04:38:00Z
grounded: converges/high — A second frontier lab — after OpenAI's Astra rerouting episode — allegedly substituting an unreleased model into pinned sessions is Anthropic newly enacting the
2026-10-02T04:29:43Z
case created — A specific, checkable release-detection claim anchored on the claimant's own X artifact, distinct from OpenAI's silent-rerouting episode and from the fallback-misroute report in this batch.