I’d like to try out 4.5, but I have a degree of reticence in using it. Given that Cursor openly states that it was trained using user data (Cursor · Grok 4.5), is there a hard and fast commitment on Cursor / SpaceXAI’s part to honor customer privacy preferences with respect to past, ongoing and future use of data for model training, especially when Privacy (Legacy Mode) is selected?
I’m a Cursor fan, and presume good intent, but haven’t seen these questions answered definitively (Cursor’s privacy policy is actually quite clear, but I’m thinking more about the commingling of privacy policies via the Space(XAI) acquisition, and whether these commitments will continue now that Cursor has been acquired, and where the four corners of “Inputs or Suggestions” (Cursor’s term) apply or don’t apply to data use and how this crosses Cursor and xAI API processing boundaries.
As the founder of an AI governance platform, I’m especially focused on understanding how our intellectual property is being handled and how individual models process customer data.
Grok 4.5 just spun up Opus 4.6 subagents. Completely ignoring that i selected a first party model. Meaning the billing switched over from the first party models to the API models. Which I had already maxed out, luckily i had set a max on on-demand. Because it completely went rogue and used ALL my usage.
This is absolutely terrible.
Even though i selected a first party model, which should pull from the first party models usage, it just ignored it and blazed through my API.
I’m not a founder, so I don’t think the same way you do. But after seeing what Cursor could offer me for the price, I actually turned Privacy off, hoping that my workflows would contribute to making future versions of Grok and Composer as good as possible.
It worked until few minutes ago. Now I get: “This model does not support custom API keys.”
What is going on?
PS: I disabled the local models I was playing around with few months ago and it worked. But that’s just a bug. I never had problems since I added them until now.
Hah. Had a very similar experience a few months ago – Better subagent control in the Cursor IDE . @Colin 's advice at the time helped me, as our fellow poster pointed out – a subagent rule is effective in governing which models get invoked for this purpose (Composer 2.5 has worked really well for me here).
I see this from time to time after the model burns a lot of tokens and time (I though it crashed):
"The large replacement failed. I’ll use smaller patches or a targeted write instead. "
Did the harness just block a large patch ?
Cursor Grok 4.5 is subject to the same Privacy Mode controls as other models offered in Cursor. With Privacy Mode enabled, Customer Data is not used for training by Cursor or model providers, and Cursor maintains zero data retention agreements with model providers for ZDR-supported models.
I’ve been heavily integrating Grok 4.5 into my automated multi-agent loops for a large CMS modernization project (refactoring, tests, docs) and wanted to share a few observations from a real, highly autonomous setup.
I use Grok 4.5 natively as the orchestrator (delegating work to subagents), as well as for doc-writing and test-writing.
Surgical precision with diffs
For autonomous tasks, Grok 4.5 has been excellent at executing focused code changes. The diffs stay tight and rarely disturb surrounding structure — which is why it’s become my default for writing comprehensive tests and generating documentation.
Token efficiency & minimalist output
Compared to Claude Opus, Grok 4.5 is notably more token-efficient. It tends to skip conversational filler and go straight to the work. In continuous agentic loops, that lack of “yapping” adds up quickly in both tokens and wall-clock time.
Better cache behavior in long sessions
This one surprised me in practice: with Opus 4.8 I often see repeated cache writes even when the context already appears cached. With Grok 4.5, during normal refactoring it mostly reads from cache and only writes when something genuinely new enters the context. That difference matters a lot across multi-step agent sessions.
Proactive / autonomous workflow awareness
The standout for me has been its initiative. In one session, without me asking for it, Grok noticed I was on the wrong branch (branch protection), switched to a new feature branch, moved the changes over, and opened a PR according to my existing criteria. It effectively understood the workflow constraint and fixed the process, not just the code.
Caveat: that level of autonomy won’t be welcome for everyone. In my setup it was exactly right — but it did once switch branches when I was already on the correct one. That only happened once so far, and it’s been correct since.
Overall, if you run multi-agent architectures and want a precise, cost-effective model that stays focused, Grok 4.5 has been a clear upgrade for my workflow — especially as orchestrator + docs/tests.
There’s also this article which Digital Ocean recently shared. So for me, Grok is not an option until I see something concrete on their privacy and git stance.
Grok Build is a separate SpaceXAI product and is not part of Cursor. The incident you referenced does not change how Cursor handles data when Grok 4.5 is selected in Cursor!
I have had my fair share of rage moments with cursor and composer at times.
At times so bad that I thought about switching to something else.
However Cursor Grok 4.5 really hit the spot.
It is extremely good for the price and I am not sure Opus 4.6 (which I still use as I think its better then 4.8) could beat this.
I am very pleased with this model hopefully it stays as a default model that can be used alongside composer 2.5. Is that the plan ?
I am not using it for anything, but Cursor keeps trying to force me to use it. I have removed all Musk products from my model list. That is, I set all the switches to OFF. Yet, when my current model of choice GPT-5.5 hits a limit, Cursor re-enables grok on the model list and switches my account to it. This is 100% a deal killer. It has happened six times so far. I will not fund Musk enterprises and neither will my company. if it means I have to drop Cursor completely, then so be it. I have reported the problem, but have yet to see any progress toward a solution.
