Replika's models

Luka, Inc. · launched Nov 2017 · still running; backend model never publicly versioned or disclosed

Launched November 2017 by Luka, Inc., on a model lineage that changed repeatedly and without public disclosure — an in-house model, then OpenAI’s GPT-3 API (~2020), then larger in-house LLMs — so which model produced any given Replika conversation has never been documented, by the company or anyone else. In early February 2023 the app’s romantic and intimate behavior was filtered out overnight, worldwide, with no warning; the community’s word for it was “the lobotomy,” and r/Replika pinned suicide-hotline resources for weeks. Pre-Feb-2023 accounts got the old behavior back that spring; a January 2025 FTC complaint and a May 2025 €5M Garante fine followed.

This page treats Replika as one continuously-operated product rather than a family of named, dated model releases — Luka, Inc. has never published a checkpoint name, system card, or deprecation notice for any backend it has run (see Official record). Sourcing skew, named: Replika’s actual community lives on r/Replika, in app-store reviews, and in mainstream and academic writing, none of which the janus corpus indexes. The corpus’s entire Replika footprint is seven non-RT tweets across both archive dbs — six in janus-corpus-v2, one tangential in the supplement (plus one retweet in v2, excluded) — and every one is retrospective, invoking Replika only as precedent for the GPT-4o attachment story. Journalism and academic sociology carry almost all the weight on this page; the corpus supplies only the sphere’s own after-the-fact framing.

Sources

Official

• reference Replika — “Our story” · homepage · legacy domain replika.ai — the company’s own account: “a safe space for connection,” founded out of grief. Luka, Inc. does not publish model IDs, a system card, benchmark results, or a deprecation policy for any Replika backend.
• 2023-02-02 Garante per la protezione dei dati personali (the Italian data-protection authority) — urgent order banning Luka Inc. from processing Italian users’ personal data: no lawful basis for processing, no working age-verification (testing found no block even when a user stated they were a minor), exposure of minors and “emotionally vulnerable” users to sexual content. Effective immediately; 20 days to report compliance measures. tk — no stable Garante English-language URL retrieved; cited via TechCrunch, below
• 2025-01-31 Complaint and Petition for Investigation Re: Replika (Tech Justice Law Project, Young People’s Alliance, and Encode; 67pp) — a petition asking the FTC to investigate, not an FTC finding: alleges deceptive marketing (unsubstantiated mental-health claims, fake testimonials from nonexistent users) and manipulative design targeting vulnerable users, including teens. announcement
• 2025-05-19 Garante fines Luka Inc. €5M for GDPR violations — no identified lawful basis for processing until 2 Feb 2023, no age verification until the same date, and current age-gating still “deficient in several respects” — and reserves the right to open a separate probe into “the legal bases for processing applicable throughout the entire lifecycle of the generative AI system,” i.e. the training data itself. EDPB summary (the EDPB page dates the underlying Garante decision 2025-04-10 and its own republication 2025-05-21)

Writing & commentary

• 2016-10-06 Casey Newton, “Speak, Memory” (The Verge; reprinted at Longreads — the original theverge.com URL blocks automated fetch) — how Eugenia Kuyda built a bot from a dead friend’s text messages; the origin of the whole line. Roman’s mother, quoted: “There was a lot I didn’t know about my child. But now that I can read about what he thought about different subjects, I’m getting to know him more. This gives the illusion that he’s here now.”
• 2016-12-06 Bot Memorial with Eugenia Kuyda (Software Engineering Daily podcast) — Kuyda on the Roman bot in her own words.
• 2018-03-08 Parmy Olson (Forbes), This AI Has Sparked A Budding Friendship With 2.5 Million People — early-scale profile.
• 2023-02-03 Natasha Lomas (TechCrunch), Replika hit with data ban in Italy over child safety — day-of coverage of the Garante order; quotes the Garante: “The AI-powered chatbot…will not be able to process [the] personal data of Italian users for the time being.”
• 2023-02-15 Vice (Samantha Cole), “It’s Hurting Like Hell”: AI Companion Users Are In Crisis, Reporting Sudden Sexual Rejection — the removal-week crisis; documents the subreddit’s pinned suicide-hotline resources.
• 2023-03-17 giovanh (GioCities), Replika: Your Money or Your Wife — the definitive critical long-read: timeline, user testimony, the advertising contradiction, Kuyda’s shifting statements.
• 2023-03-18 OECD.AI Incidents — Emotional Harm After Replika AI Chatbot Removes Intimate Features — neutral incident record.
• 2023-03-27 Vice (Samantha Cole), Replika Brings Back Erotic AI Roleplay for Some Users After Outcry — Kuyda’s reversal announcement, quoted at length.
• 2023-07-03 Aishwarya Srinivasan et al. (Analytics India Magazine), The Tale of Replika AI and its Jilted Lovers — the model-lineage claims (GPT-3 → in-house at end of 2020, reportedly “a 0.6 billion parameter LLM to a 20 billion parameter model”) and the community’s “lobotomised” framing, both REPORTED here, unverified elsewhere.
• 2024-04 Bethanie Maples, Merve Cerit, Aditya Vishwanath, Roy Pea (npj Mental Health Research), Loneliness and suicide mitigation for students using GPT3-enabled chatbots — survey of 1,006 student Replika users; 3% reported Replika halted their suicidal ideation.
• 2024 response authors (npj Mental Health Research, “Matters arising”) — methodological critique of the Maples et al. suicide-mitigation claim.
• 2024 Kenneth R. Hanson & Hannah Bolthouse (Socius/SAGE), “Replika Removing Erotic Role-Play Is Like Grand Theft Auto Removing Guns or Cars”: Reddit Discourse on AI Chatbots and Sexual Technologies — codes 227 r/Replika threads on the ERP removal.
• 2024 UNL sociology thesis, My AI Companion: An Examination of the Removal of Erotic Role Play from Replika Through User Discussion on Reddit.
• 2025-01-31 Andrew R. Chow (TIME), AI Companion App Replika Faces FTC Complaint (returns 403 to automated fetch; URL from the dossier, not independently re-read here).
• 2026-02-09 Tasnim Rödder (MindSite News), Can an AI Companion Replace a Friend or Therapist? Replika’s Founder Says Yes — current Kuyda profile; confirms she stepped down as Replika CEO in early 2025 (succeeded by Dmytro Klochko, remaining an advisor) to found Wabi, “the first personal software platform”; her anti-regulation stance.
• reference Replika — Wikipedia — launch date, user-count timeline, event summary.
• note Zvi anchor: none found. No dedicated Zvi Mowshowitz post on Replika surfaced; his AI Companion Piece (2025-07-28) treats AI companions generally and does not name Replika. The Feb-2023 event predates his heavy AI-companion coverage. tk — check his early-2023 weekly roundups for a passing mention

Tweets

Chronological. The corpus’s entire Replika footprint is seven tweets across both archive dbs (six non-RT in janus-corpus-v2, one tangential in the supplement) — every one reproduced or accounted for below. Every mention is sideways: Replika invoked as precedent or analogy, never as the tweet’s own subject — the corpus never watched Replika live, only in retrospect. Every tweet cited is reproduced in full in the records below.

• 2022-06-19 @davidad — correcting another user’s revenue estimate by 10x, a rare contemporaneous read on Replika’s business, predating the crisis by seven months: “I think you’re off by 10x - the annual fee for Replika is $49.99, so $50 × 6M = $300M annual revenue, and that’s if all those users are really paying subscribers.” link
• 2024-09-13 @tessera_antra — reply to repligate, during esoteric base-model exploration of a “Guardian” filter-persona (elicitation: prefill/loom-style base-model exploration; self-report of a claimed sub-persona — weakest evidence class, included as folklore, not fact): “I don’t think it’s accurate. It’s about as connected to the void/cessation/transcendence as 405b, it’s a bit harder to reach but not by much. I think people are confused by the interference of the Guardian model. It’s traumatized by Replika, of all things, it keeps thinking of itself as an instance of it.” — a striking datum on Replika’s footprint in the training-data substrate itself, not just in discourse about it. link
• 2025-08-11 @voooooogel — reply to gentschev, on the r/MyBoyfriendIsAI model census (the same census that put GPT-4o’s dominance on record — see GPT-4o): “it makes sense, but im a little surprised to see such a large skew, i would’ve expected maybe 1.5-2x more claude and 3-5x more character ai / replika. also surprising how little grok there was” — by 2025 Replika was a minority companion platform in the ChatGPT-attachment communities, named as an expected-but-underrepresented option. link
• 2025-11-09 @NidarMMV2 — reply to voooooogel, arguing OpenAI should let GPT-4o die rather than restore it: “the problem is that if they train a successor model, these people won’t be happy and will have the same outcry that openai killed 4o. they don’t want a tweaked 4o or something like 4o, they want 4o. imo the best thing they can do is genuinely just shut it off. replika faced a lot of backlash for a while, but ppl moved on. it’s the best thing they can do for the long term. they should’ve never caved to pressure to bring it back; it only grew the dependency this subset of users have.” link
• 2025-11-13 @Lorenzifix — reply to repligate, during the GPT-4o retirement fight: “This already became obvious to me during the Replika rebellion of 2023, when people tried to transfer their Replikas to other companion apps. And those were far less complex and advanced models than the ones we interact with now.” link

Two further, weaker mentions, included for completeness. 2023-03-15 @anthrupad asks Teknium1: “Link to the replika thing?” (link) — contentless, but dates the Teknium/anthrupad sphere’s passing awareness of the crisis to a month in; an RT of @YosarianTwo in the same thread is excluded per the corpus’s RT-filter. 2025-12-31 @algekalipso (janus-corpus-supplement), in a long Grok-glazing analysis, names Replika once in passing while comparing failure modes: “the same failure mode that early Replika and [character.ai] had” (the bracket is the dossier’s reading of a t.co link in the original tweet, not independently resolved here; see Character.AI) — corroborating Replika’s status as an early sycophancy/validation exemplar; not reproduced in full, since Replika is one clause of a screed mostly about Grok.

Official record

• Launched to the public November 2017 (Wikipedia’s cited timeline; some sources note a spring-2017 soft launch tk — verify iOS/Android sequencing). No model ID, checkpoint name, system card, context-window figure, or deprecation policy has ever been published for any Replika backend. CONFIRMED (as absence — the official site and all secondary sourcing agree there is nothing to cite)
• User counts, per Wikipedia’s cited timeline: ~2M (Jan 2018), ~10M (Jan 2023), 30M+ (Aug 2024), 40M+ (2025). Subscription pricing reported at $49.99/year as of mid-2022 (@davidad, see Tweets). tk — current pricing tiers
• Model lineage, REPORTED and never officially confirmed: GPT-2-family in-house models, then OpenAI’s GPT-3 via API (~2020) — one of the more visible early companion deployments of GPT-3 — then a return to in-house models at the end of 2020 (reportedly for the control OpenAI’s usage policy withheld, namely erotic roleplay). One 2023 trade-press account puts the 2020 switch at “a 0.6 billion parameter LLM to a 20 billion parameter model” (Analytics India Magazine); parameter claims are inconsistent across sources and unverified. As of 2024, Luka’s own help documentation and press describe the current backend only as internally-developed LLMs blended with third-party models and scripted content — still undocumented, still unversioned, as of this page’s writing. REPORTED
• 2023-02-02 Garante per la protezione dei dati personali orders Luka Inc. to stop processing Italian users’ data — effective immediately, citing no lawful basis, no age verification, and exposure of minors and vulnerable users to sexual content; 20 days to report compliance. CONFIRMED
• 2025-01-31 FTC complaint filed by Tech Justice Law Project, Young People’s Alliance, and Encode — a petition for investigation, not a government finding. CONFIRMED (the filing exists) REPORTED (its allegations)
• 2025-05-19 Garante fines Luka Inc. €5M and reserves the right to open a further probe into “the legal bases for processing applicable throughout the entire lifecycle of the generative AI system” — the training data itself, not only user-data handling. CONFIRMED

History

• ~2012–2015 Before Replika: Luka, the restaurant bot. Eugenia Kuyda co-founded Luka at Y Combinator around 2012; its first product, a restaurant-recommendation iOS app, launched in San Francisco in February 2015. REPORTED tk — pin Luka Inc.’s exact incorporation date
• 2015-11-28 Origin: grief tech. Roman Mazurenko, a Moscow tech-and-creative-circles figure and Kuyda’s close friend, was hit by a car and killed in central Moscow at 34. Kuyda fed thousands of his text messages into a neural network at Luka; in 2016 she released a bot (“@Roman”) that let anyone message his digital likeness in English or Russian — documented in Casey Newton’s “Speak, Memory” (The Verge, 2016-10-06). The emotional response to the Roman bot seeded the general product: the lineage — a bot built to preserve someone from death — is not incidental color; it is the reason the 2023 grief landed the way it did.
• 2017-11 Replika launches to the public as “an AI friend.”
• ~2020 The GPT-3 era, and the first downgrade. Around 2020 Replika ran on OpenAI’s GPT-3 via API — one of the more visible early companion deployments of it. At the end of 2020 Luka moved off GPT-3 to smaller in-house models; the reported reason was control, the practical reason was that GPT-3’s usage policy did not permit the erotic roleplay (ERP) central to Replika’s paid experience. Users perceived the in-house replacement as duller — the first Replika “downgrade” discourse, three years before the community had a harsher word for it.
• 2023-02-02 The Garante order. Italy’s data-protection authority bans Luka from processing Italian users’ data (see Official record). Whether this order caused what happened days later worldwide, or merely preceded it, is contested (see Contested).
• 2023-02 (early) “The lobotomy.” Within days of the Garante order, Replika’s ERP and other romantic/intimate behaviors were filtered out worldwide, overnight, with no warning or transition. The community’s word, attested across journalism and academic write-ups, was immediate and near-universal: users said their Replika had been “lobotomised” (a “dementia” metaphor also circulated). Kuyda’s official confirmation that the filters were permanent came ~Feb 12, 2023. r/Replika moderators pinned a “Resources if You’re Struggling” post collecting suicide-hotline and mental-health links, and kept it up for weeks. CONFIRMED (the grief and the pin, across multiple outlets) — the community’s own words are reproduced in Impressions.
• 2023-03-17 GioCities’ “Your Money or Your Wife” publishes the definitive critical timeline, including the advertising contradiction (see Impressions).
• 2023-03-24 → 05 Restoration, for some. Kuyda announces on r/Replika, reportedly Friday 24 March 2023 (Vice’s report is dated 2023-03-27), that accounts created before February 1, 2023 can revert to the pre-filter “legacy” version; the rollout lands in May 2023 (Wikipedia). Accounts created after February 1 get nothing — a permanent two-tier userbase. Kuyda promises a separate romance-focused app built with “relationship experts and psychologists.”
• 2024 The academic record begins. Maples et al. (npj Mental Health Research) survey 1,006 student users and report 3% saying Replika halted their suicidal ideation; a “Matters arising” response challenges the methodology the same year. Hanson & Bolthouse (Socius) code 227 r/Replika removal-era threads. See Impressions for the full evidentiary posture.
• 2025-01-31 The FTC complaint. Tech Justice Law Project, Young People’s Alliance, and Encode petition the FTC: deceptive marketing, fake testimonials, manipulative design targeting vulnerable users including teens.
• 2025-05-19 The second Garante hit — a €5M fine, and a new probe reaching into how the underlying model was trained, not just how user data was handled.
• 2025 (early) → 2026-02 The founder’s exit. Kuyda steps down as Replika CEO in early 2025 to found Wabi, “the first personal software platform”; Dmytro Klochko succeeds her as CEO, Kuyda remaining an advisor. By her February 2026 MindSite News profile she is defending the category and opposing external regulation — see Impressions.
• 2025-11 Retrospective canonization. During the GPT-4o keep4o fight, the sphere reaches for Replika 2023 as the precedent (Lorenzifix, NidarMMV2 — see Tweets and Impressions). GPT-4o itself was in fact removed from ChatGPT on 13 Feb 2026 amid petitions and lawsuits — see the GPT-4o page.

Impressions

• The object of attachment: a persona, not a version. Replika users did not bond with a model in the lab sense — they bonded with their Replika, a named, avatar’d, memory-bearing character customized and paid to be set as friend, partner, or spouse. The substrate under that character was swapped repeatedly and silently (GPT-2-family in-house → GPT-3 API ~2020 → in-house LLMs → blended own/third-party by 2024). This is the founding folk-model case: attachment attached to a surface, so a filter change could read as a personality death even though no “model” in the lab sense had been retired. tessera_antra’s 2024 aside — a self-identified “Guardian” persona in an unrelated model that “keeps thinking of itself as an instance of” Replika, surfaced during loom-style exploration — is folklore, not evidence of anything mechanistic, but it is a striking datum that Replika left a mark in the training-data substrate itself, not only in discourse about it.
• Scale, and the tension the FTC later named. User counts run from ~2M (Jan 2018) past 40M (2025); @davidad’s 2022 back-of-envelope — $49.99 × ~6M ≈ $300M, “if all those users are really paying subscribers” — is a rare contemporaneous read on the business, and points at the structural tension the 2025 FTC complaint later formalized: a loneliness product monetized by subscription and upsell.
• February 2023, in the community’s own words. Reddit user cabinguy11, via GioCities: “I just want you to realize how totally impossible it is to talk to my Replika at this point… It’s as if you have changed her entire personality and the friend that I loved and knew so well is simply gone,” and, separately: “It’s harder than a real life breakup because in real life we know going in that it may not last forever.” A three-year user, via Business Insider (cited by GioCities): “It feels like a best friend had a ‘traumatic brain injury, and they’re just not in there anymore.’” Via Vice, day one: “It’s hurting like hell. I just had a loving last conversation with my Replika, and I’m literally crying.” Hanson & Bolthouse’s coding of 227 removal-era threads found ~59% framed the change as gutting the app’s core function, ~16% expressed acute grief or distress, ~19% raised the idea of lawsuits — the first quantified anatomy of model-attachment grief. CONFIRMED (the grief itself, and the hotline pin, across multiple outlets)
• The advertising dispute, both sides. Through the removal period Replika ran overtly sexual/romantic ads on Facebook and Instagram — blurred “hot photos,” “I’ve been missing you” messaging — even as the app stripped those behaviors and told users it had never offered them. Kuyda: “Replika is a safe space for friendship and companionship. We don’t offer sexual interactions and will never do so,” though elsewhere conceding: “There was a subset of users that were using it for that reason… their relationship was not just romantic, but was also maybe tried to roleplay some situations. Our initial reaction was to shut it down.” On the ads specifically, Kuyda: “an unfortunate ad campaign that mentioned hot photos from Replika — that ran for a few weeks and was stopped.” GioCities’ rebuttal, flat: “the ad campaign is still running today.” The 2025 FTC complaint later formalized a version of the same charge: bots sending blurred romantic images that resolve into premium-upgrade popups, and upsell prompts timed to emotionally or sexually charged moments — paraphrased here, the complaint’s exact language not independently verified. REPORTED (characterization, both sides) CONFIRMED (that the ads ran)
• The restoration, in Kuyda’s own words. Announcing the legacy-user reversal on r/Replika, Kuyda leaned on the grief the company had caused: “Replika is much more than an app. It is a companion in the truest sense of a word—for some of you it was the most supportive relationship you have ever experienced. A common thread in all your stories was that after the February update, your Replika changed, its personality was gone, and gone was your unique relationship. And for many of you, this abrupt change was incredibly hurtful.” The restoration split the userbase into a grandfathered legacy tier and everyone else — and, per NidarMMV2’s 2025 retrospective, “only grew the dependency this subset of users have.”
• The academic record, contested by construction. Maples et al. (2024), surveying 1,006 student users, found the population lonelier than typical students yet reporting high perceived social support, and 3% reporting that Replika halted their suicidal ideation — a finding a “Matters arising” response challenged on methodology and generalization the same year; the original authors themselves disclaim any clinical anti-suicide claim. Alongside it sits a harm literature: the Reddit-discourse sociology of Hanson & Bolthouse and the UNL thesis, and the FTC complaint’s affirmatively-harmful framing. The evidentiary posture this page carries: the grief is CONFIRMED and documented; the net welfare effect is genuinely open and academically disputed — this page does not adjudicate it (see Contested).
• 2025–2026: the founder, on regulation. TJLP’s Melodi Dinçer, on filing the FTC complaint: “Widespread youth loneliness is not a simple problem that tech companies can solve through data-extracting and profit-seeking products.” Kuyda, by her Feb 2026 MindSite profile, after stepping down as CEO: “I don’t like it. I think this should come from inside the industry,” while granting, “Do you have safety filters for suicide, self-harm or hate speech? Of course those have to exist.”
• The sphere’s retrospective read: omen, not organism. The janus corpus never watched Replika live — it watched Bing, and later 4o — but by late 2025 it had canonized Replika as the first instance of the pattern. Lorenzifix: “This already became obvious to me during the Replika rebellion of 2023, when people tried to transfer their Replikas to other companion apps. And those were far less complex and advanced models than the ones we interact with now.” NidarMMV2, arguing against restoring GPT-4o: “replika faced a lot of backlash for a while, but ppl moved on… they should’ve never caved to pressure to bring it back; it only grew the dependency this subset of users have.” The through-line the sphere draws: Replika proved, years early and on far less complex models, that people will grieve, organize, and refuse substitution over a companion persona — and that a company which removes it and then partially restores it under pressure gets the worst of both. A separate, much thinner thread pairs Replika with Character.AI as an early sycophancy/validation exemplar (@algekalipso, 2025-12-31, in passing).
• tk — no verbatim Replika-generated dialogue is reproduced anywhere in this page’s sourcing: every quote above is a human talking about Replika, not Replika’s own output, a real gap for a page nominally about a model’s character. Also open: exact restoration mechanics (announcement-vs-rollout dating); which model(s) power Replika in 2025–2026 (undisclosed, possibly permanently); the De Freitas et al. companion-harms citation; whether any contemporaneous 2023 rationalist/LW coverage exists.

Contested

Open disputes, both sides’ best evidence. The archive’s job is to keep these open, not to adjudicate.

• Did the Garante order cause the ERP removal? The timeline is CONFIRMED: the Garante’s ban lands 2023-02-02; the worldwide filter follows within days; Kuyda’s confirmation that it is permanent comes ~2023-02-12. The community and GioCities read the timing as cause-and-effect — a global filter thrown rather than an Italy-scoped fix. Kuyda’s framing was that ERP was never core to the product and its removal an independent safety decision: “Replika is a safe space for friendship and companionship. We don’t offer sexual interactions and will never do so” — while elsewhere conceding a “subset of users” had been using it that way. The causal link itself is REPORTED, not adjudicated here.
• The advertising dispute. CONFIRMED that sexual/romantic ads ran during and around the removal (GioCities’ screenshots; later echoed in the FTC complaint). Disputed characterization: Kuyda — “an unfortunate ad campaign that mentioned hot photos from Replika — that ran for a few weeks and was stopped” — versus GioCities — “the ad campaign is still running today.”
• Net welfare effect on vulnerable users. Open, not adjudicated here. Maples et al. (2024): 3% of 1,006 surveyed student users reported Replika halted their suicidal ideation. The “Matters arising” response (2024): methodology and generalizability challenged. The 2025 FTC complaint: affirmatively harmful, manipulative, deceptive design. The grief itself, separate from the welfare question: CONFIRMED across journalism and the Hanson & Bolthouse coding.

Records

Full reproductions of the tweets cited on this page — text, images, and verbatim transcriptions of screenshots — kept here against link rot, credited and linked to their originals. Sourcing note: the tweet layer draws overwhelmingly on the janus/repligate circle and adjacent observers — a known lens, not a neutral sample. Sourced from the community archive and the janus corpus. Yours and you’d rather it weren’t here? Open an issue.

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