Auto mode is now the default in Claude Code
227 points - today at 3:50 AM
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Very often, when I'm running Claude in manual review mode, it will attempt to do things which are not "dangerous" but are misaligned with what I want it to do. Maybe I'm fighting the model here but for example, when orchestrating other agents to do work, Claude really badly wants to be overly prescriptive about how the work gets done, telling them exactly which files to edit, exactly what not to do, etc. instead of trusting the guardrails, review agents, or humans in the process to catch code-level mistakes. And no, telling it not to do this does not stick. Manual review is the last line of defense I have here.
I have stuff I don't want blacklisted, only allow it to use tools with limited ability to boss around agents, and various hooks to try and catch behavior that the permissioning system can't. If I use Auto mode though, I lose this control. The classifier will gleefully approve these types of commands because guess what, it's also Claude.
Yeah, might make sense from their perspective, but no thank you. I also do click through at times without reading everything, but I like to stay in control, learn about the new code and change direction if it goes off track. This would just burn more tokens because I have to throw away much and I hope my manual approval settings will be respected also with future updates (or I jump ship).
https://github.com/anthropic-experimental/sandbox-runtime
This is combined with "auto" mode.
Seems to work so far. I've manually checked various things, rw access, access to sensitive folders/files etc.
So far, I've only used it on two small projects. My major projects I've been clicking through prompts and recently switched to "auto" mode.
I'm not quite sure why anyone would trust "--dangerously-skip-permissions". I've seen these agents go off-piste far too many times, installing unnecessary packages, environments, calling sudo & creating files in all sorts of places.
There's a page on various sandboxing strategies on their site:
https://code.claude.com/docs/en/sandbox-environments
I've seen various comments in several topics with folk baking their own sandboxes. That's great. Although I'd be inclined to try Anthropic's solutions initially.
I've been using auto mode ever since the feature was released. Apart from a very few occassions where the classifier blocked a safe command, I have faced no issues and continue using it as my default mode. It's great!
If you're using yolo mode, this is a no brainer upgrade.
The model first classifies the safety of the command in isolation, no thinking involved. Sonnet 5. Goes to second stage only if it's likely unsafe, in which case the model next considers your intent (Your prompt, CLAUDE.md and any answers to the questions).
The model doesn't receive the full transcript to reduce surface area of the prompt injection. It mostly receives your prompts and main model's tool use blocks. So any text in files, website fetch or bash command output doesn't influence the decision in anyway.
However, CC puts a lot of trust in main model still. For example, `npm install` will always be classified as safe by the auto-classifier, it's upto the main model to ensure that the packages.json isn't poisoned in someway by first reading it.
Reliance on safety of the main model is the reason that Auto mode is NOT available with Haiku as the main model.
I was recreating an old travel blog and we wanted to back up the photos to glacier.
Claude asked me to creat an AWS profile with limited permissions so I could run a script it had created.
I did it and told Claude it was ready.
It took that to mean it should run the script.
It failed as I’d messed up one of the permissions.
“Don’t worry - I’ve found another configured AWS profile - it’s got admin permissions! I’ll just use that…”
Completely my fault for having that old profile still available. But also…
I've been experimenting with dedicated Linux users for various external tools with access to the relevant credentials limited to them and the Claude user only able to invoke the relevant clis by going through a pair of wrapper scripts: the first to change user to call the second via a su call as the appropriate user, the second wrapper to invoke a guard script which allows me to implement my own in-code permissions checks against the cli arguments. In _theory_ there's no way for Claude to work around it, as the sudoers file only permits the described manner to change to the user with credentials, and the user with permissions for each credential only ever runs deterministic code.
It's too early days to say how well this second part works out, but so far so good.
>The testers caught the dangerous command just 13.6% of the time (143 of 1,053), while auto mode blocked 89% of the same commands (937 of 1,053). Head to head, auto mode blocked 800 commands that a human approved, while humans blocked only 6 that auto mode allowed. As sessions got longer, humans did worse: they blocked about 17% of dangerous commands early in a session, dropping to about 5% after 50 or more prior prompts, while auto mode's block rate stayed flat regardless of session length.
Any note on the proficiency, expeirence, and skill levels of the testers? 'cos the diff in numbers is absurdly high.
Now: get GPT to do some work, have Claude review it, question Claude about a finding that is surprising to me because I thought the functionality was already in place.
[Claude/Opus 5 Max goes looking] "You're right — I was wrong about that."
Our Claude license ends in about 2 weeks and we're not renewing - this has been par for the course for the last 2 months now.
And their marketing is really starting to bother me, on top of that.
"Oh you're piping grep into sed, I have no idea what the implications of that are!"
The more complex bash scripts are perhaps better or more efficient, but it feels like it's training us to give up more control to the agent.
I'd prefer to have an auto mode for read-only operations and go back to simpler commands for write operations that I can personally whitelist or manually accept.
I've been using Opus 4.6 for some security related work (it has much looser guardails that later opus models) and last week, all of a sudden, the processes started to fail. It wasn't the main model blocking commands but the auto mode classifier changed how it worked and it started blocking the main models commands.
That's one specific incident, but it does have a wider potential problem which is, if you use Anthropic's harness you'll always be at the risk of sudden breakage from server-side changes that are opaque to the end user, which is a tricky one for building long lasting processes.
Obviously, they are the ones we must trust.
I can see why they want that, but I'm honestly not sure it's the path to the best outcome. In my view, agents should run in full sandboxes and have host features opted in. Yeah, it's going to be painful and it will limit some adoption in the short term. But I just don't think they are on the right side of what a lot of companies will ultimately need here. Agents are way too smart to be run on the host OS directly with any amount of heuristic sandboxing.
On the other hand, soooo many of the tool uses it asks permission for are custom commands to replace functionality I should be able to trust once instead. e.g. instead of having a trustable Find tool, or using its already-trusted Read tool, it often will run `find` or `grep` or `cat` with a series of pipes and substitutions or `-exec` args, requiring me to give permission every time for basic, safe operations.
The (increasingly active) conspiracy theorist inside of me says it's precisely designed to do that, to give me "permission fatigue", so I turn on auto mode and give myself over to the machine spirit :)
Per this announcement, they've stopped charging for the tokens used by this safety classifier.
So not surprisingly, auto mode is the only sane way to use Opus 4.7+.
Seems to me that the API should be more general.
I have been using Codex with auto-approve mode for a couple months and haven't had a single incident (or at least haven't noticed). Maybe as capabilities get better and better and they are less likely to do something dumb like wiping ~/, we can just trust them?
I guess this argument works unless we worry about agents doing something out of malice instead of stupidity.
This now looks like a deliberate UX choice to blame humans who don't review options, and then just remove the choice. A dark pattern to push the product.
A lot of the discussion about these long sessions where agents are left to operate autonomously feels like listening to the increasingly drunk guy at the bar who says "I ran IT at that Fortune 100 place for a decade and we never had a single problem using a short but loose rule set for the firewall until last week someone destroyed our entire business in 27 minutes".
Just yesterday i struggle to review CC command histories, and made this tool to help me review https://github.com/slaveofcode/eridian
Claude's 'auto mode' feels like a solution to a problem that shouldn't exist.
Cursor handles this much better IMO. When the agent wants to run a command, Cursor lets you choose between 'allow once' and 'add command to allowlist'. The latter lets the agent run that command (grep, ls, pwd etc) any number of times for that project, which means you get a lot of these manual reviews when you start a new project but rarely (if ever) thereafter.
I've never used a product where I felt it was best in class and they just keep making me regret it .
I am seeing 96Gb Mac studio 3rd gen I think for a good amount but I guess it would be better than paying for mac mini newer models with lesser ram?
Or would it make sense to buy used 32 GB Mac mini 3 or 5?
Is there a cost/dollar for various generations which I could compare against used market and pick the most effective one?
What’s the best way to sandbox Claude on macOS without it being a huge hassle?