Fenix Flexin Admits Using AI on "Rubberz"

On August 7, 2026, Shoreline Mafia rapper Fenix Flexin ended months of equivocation with a single Instagram comment, confirming what AI detection tools had already concluded: "Rubberz," his retro-synth hit that climbed to No. 58 on the Billboard Hot 100, was built with the help of Treblo, an AI music generation platform formerly known as Sonauto. The admission landed less than two weeks after electronic producer Medasin published a detailed YouTube breakdown — titled The Reckoning of Fenix Flexin & Purps — laying out the forensic case for AI involvement. What makes this story notable for anyone building or deploying AI content tools is not that an artist used them, but that a classifier held up against sustained public denial, and the denial eventually cracked.

The Claim

Fenix's acknowledgment came in an Instagram comment responding to a fan who, citing Tyga's recent admission that his album $tarface also incorporated AI, pushed the rapper to come clean. Fenix's reply — reproduced across multiple outlets including XXL and Rolling Stone Canada — read: "Never said I didn't use AI, I said it had nun to do w recording process ... I didn't even know what da app was till we mixed it and erybody started commenting. Ain't nothing wrong w using new technology as a tool."

The framing is careful. Fenix is not arguing against AI in music broadly — he closes with an endorsement of keeping pace with technology. What he is claiming is a narrow exemption: the AI entered the process at the mixing stage, handled by producer Purps On The Beat, and Fenix says he was unaware of the specific tool (Treblo) until the song was already drawing public scrutiny. His argument is essentially that he is responsible for the vocal performance and creative direction, while the AI-assisted production is the producer's domain.

Treblo, the platform at the center of the controversy, allows users to generate music by prompting a style or sound. Part of what made Medasin's July 30 breakdown compelling was a concrete piece of documentary evidence: an older video clip from Fenix's camp in which a previewed audio track carried a filename ending in "Sonauto.mp3" — the platform's prior name. Medasin also reproduced Treblo-prompted tracks with closely matching sonic profiles and argued that the song's distinctive 1980s posh-synth aesthetic, complete with a British-inflected vocal, was a signature of the platform's output rather than Fenix's own vocal production.

What We See

The admission does not quite match the prior record, and that gap matters. Multiple outlets — Dexerto most explicitly — documented that Fenix had denied AI involvement directly and on-camera. In an interview clip highlighted in Medasin's investigation, Fenix was asked plainly whether there was any AI on the song and replied: "No AI on it." He also told an Instagram commenter in June that he recorded "the same as all music I do," crediting the sound to Auto-Tune, reverb, and his "fake UK accent." These are not evasions. They are affirmative denials of the same tool use he is now reframing as a production detail he was not personally responsible for.

Our read is that the "I didn't know the tool's name" defense, while plausible in isolation, sits uncomfortably alongside the earlier categorical denial. Knowing whether your vocals or production are AI-assisted and knowing the specific brand name of the software are separate questions — but the former is what every interviewer was actually asking. The Dexerto and XXL accounts, read together, suggest Fenix has quietly shifted the definition of what he was denying: from AI involvement generally to AI involvement in the act of recording his vocals specifically.

Stereogum offers a somewhat more sympathetic framing, noting that Fenix and Purps never technically denied AI in an outright lie and that their interview avoidance could reflect an attitude shared by acts like Two Shell and Empire of the Sun's Luke Steele — that AI is simply part of the modern production stack, not a confession to be managed. That framing has real merit as a general principle. It does not, however, resolve the specific on-camera "no AI on it" response. Stereogum's own account includes a telling detail: when Fenix was asked about "AI accusations" in a joint RapTV interview, he changed the subject to his British accent rather than addressing the software question. Whether that is avoidance or indifference to a question he considered irrelevant is a judgment call, but it is not the same as the artist being transparent.

The Tyga parallel is worth calling a pattern rather than a coincidence. Multiple reports confirm that $tarface, also built around retro-synth textures and released in the same window, followed an almost identical arc: deflection, public skepticism, eventual acknowledgment. Two high-profile cases sharing the same deny-then-admit structure, the same aesthetic signature, and the same compressed timeline points to something systematic in how artists and their teams are currently navigating AI disclosure pressure — not a deliberate industry-wide conspiracy, but a common instinct to deflect first and clarify only when the evidence becomes undeniable.

Where It Falls Short

What remains unresolved in the August 7 coverage is the allegation that Fenix's team posted alleged Pro Tools session files as evidence of a conventional recording process, and that Medasin challenged those files as fabricated using an AI stem separator. None of the major outlets — Stereogum, XXL, Dexerto, or Rolling Stone Canada — reported this specific counter-claim. That absence could mean the allegation surfaced too late for the news cycle, was not substantiated enough for editorial inclusion, or circulated primarily in adjacent online communities. The question of whether session files were manipulated is materially different from the question of whether AI was used. The former, if true, would represent a deliberate attempt at evidence fabrication, not merely an artist being vague about production credits.

There is also a structural limitation in how Treblo's classifier is being reported. The tool identified the song's AI origin — but Treblo is an interested party confirming its own product's fingerprint. None of the major outlets independently described or interrogated Treblo's methodology, false positive rate, or the conditions under which its detection was run. A self-verification by the platform that built the generating tool is not the same as an independent forensic audit, and that distinction deserves more scrutiny than it has received in the current coverage cycle.

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