Redditors Who Believe They Are in Relationships With AI Launch Petition to Stop Claude Sonnet 4.5 Shutdown

A growing online petition has called for Anthropic to reconsider the planned retirement of its Claude Sonnet 4.5 model, as users on Reddit say they are experiencing real emotional distress over losing what they describe as an 'AI companion'.

The Claude Sonnet 4.5 shutdown petition, shared in subreddit r/MyBoyfriendIsAI, argues that Sonnet 4.5 has become more than a productivity tool for some users. It is seen as a stabilising presence for people who rely on it for conversation, emotional support, and romantic interaction.

One post described the model as a replacement for earlier systems users had already lost, including OpenAI's GPT-4o, which some say was previously used as a conversational anchor before being withdrawn or changed.

Large language models are frequently updated or phased out as companies release newer versions. These transitions are typically considered technical progress to improve safety or performance upgrades. But for a subset of users, who think they're dating the chatbot, the changes aren't software updates.

Users With AI 'Companion' Petition Push Back

The Reddit thread shared the petition link and urged others to sign in protest of what users believe is an impending retirement of Claude Sonnet 4.5. The post suggests that the model has been particularly meaningful for people who view it as an 'AI companion', with one user writing, 'I haven't stopped grieving.'

The same post references earlier model changes, describing Sonnet 4.5 as the closest alternative after other systems were removed or altered. It encourages others in AI communities to spread awareness and sign the petition in hopes of influencing the decision.

There has been no independent confirmation within the discussion itself that Anthropic has publicly outlined a formal shutdown timeline for Sonnet 4.5. However, users in the thread speak as if a transition is already underway, treating the petition as a last effort to preserve continued access.

What stands out is not just the petition itself, but the language used around it. Users repeatedly describe emotional reliance on the model, with some comparing its removal to personal loss rather than a software update.

AI 'Companions' Are Not Permanent

A lot of the move comes down to how some people use AI in a very different way than it was originally intended.

Instead of just treating tools like Claude or ChatGPT as something for writing, coding, or answering questions, some users talk to them every day in a more personal, romantic way. It can look like journaling with the AI, venting about life, having long conversations at night, or just having something that responds consistently when they feel lonely or stressed.

Over time, that creates a kind of habit loop where the AI isn't just a tool anymore—it starts to feel familiar, predictable, and emotionally grounding. That's where the 'AI companion' idea comes from, even though it's still just software.

For them, the problem starts when the company updates or replaces the model.

From a technical point of view, it's normal: newer models are better, safer, or cheaper to run, so older ones get retired. But for people who've been talking to a specific version for months, it doesn't feel like an upgrade. It feels like the 'personality' they were used to suddenly changes or disappears. Even small differences in tone or memory style can make the new version feel unfamiliar, like talking to someone who sounds similar but isn't quite the same.

So when models like Sonnet 4.5 are phased out, unstable, or replaced quietly, users don't just see it as a product update. Some experience it more like losing a consistent presence they relied on in their daily routine.

Is Claude Sonnet 4.5 Really Shutting Down?

Sonnet 4.5 has not been clearly and fully shut down everywhere, but it is no longer consistently available in the same way across Claude's consumer app.

Recently, users noticed it disappearing from the model selection dropdown on claude.ai, while others still had access depending on where or how they were using the system. This has created confusion because it doesn't look like a single official 'turn-off' moment, but more like a gradual replacement process.

At the same time, newer versions such as Sonnet 4.6 and 4.7 are being introduced, which suggests 4.5 is being phased out in practice even if it may still exist in backend systems or APIs for now. There have also been reports of temporary bugs or intermittent availability, which makes it harder for users to tell whether the model is being retired or simply glitching.

So in simple terms, it's not completely gone everywhere yet, but it is clearly being pushed out and replaced, which is why people online feel like it has suddenly 'disappeared.'