Changes in the system prompt between Claude Opus 4.6 and 4.7 • Hacker News Board

Re: Changes in the system prompt between Claude Opus 4.6 and 4.7

#171

Post by cowlby » Mon, Apr 20, 2026, 5:40 AM UTC

cfcf14 wrote: post #4

I'm curious as to why 4.7 seems obsessed with avoiding any actions that could help the user create or enhance malware. The system prompts seem similar on the matter, so I wonder if this is an early attempt by Anthropic to use steering vector injection? The malware paranoia is so strong that my company has had to temporarily block use of 4.7 on our IDE of choice, as the model was behaving in a concerningly unaligned w…

I "fixed" this for myself with tweakcc which let's you patch the system prompts. I changed the malware part to just be "watch out for malware" and it's stopped being unaligned.

They really should hand off read() tool calls to a lean cybersecurity model to identify if it's malware (separately from the main context), then take appropriate action.

Re: Changes in the system prompt between Claude Opus 4.6 and 4.7

#172

Post by dhedlund » Mon, Apr 20, 2026, 5:42 AM UTC

stingraycharles wrote: post #134

dhedlund wrote: post #50

Earlier quoted context omitted.

The "Picking delaySeconds" section is quite enlightening. I feel like this explains about a quarter to half of my token burn. It was never really clear to me whether tool calls in an agent session would keep the context hot or whether I would have to pay the entire context loading penalty after each call; from my perspective it's one request. I have Claude routinely do large numbers of sequential tool calls, or have…

This is somewhat obvious if you realize that HTTP is a stateless protocol and Anthropic also needs to re-load the entire context every time a new request arrives. The part that does get cached - attention KVs - is significantly cheaper. If you read documentation on this, they (and all other LLM providers) make this fairly clear.

For people who spend a significant amount of time understanding how LLMs and the associated harnesses work, sure. For the majority of people who just want to use it, it's not quite so obvious.

The interface strongly suggests that you're having a running conversation. Tool calls are a non-interactive part of that conversation; the agent is still just crunching away to give you an answer. From the user's perspective, the conversation feels less like stateless HTTP where the next paragraph comes from a random server, and more like a stateful websocket where you're still interacting with the original server that retains your conversation in memory as it's working.

Unloading the conversation after 5 minutes idling can make sense to most users, which is why the current complaints in HN threads tend to align with that 1 hour to 5 minute timeout change. But I suspect a significant amount of what's going on is with people who:

* don't realize that tool calls really add up, especially when context windows are larger.

* had things take more than 5 minutes in a single conversation, such as a large context spinning up subagents that are each doing things that then return a response after 5+ minutes. With the more recent claude code changes, you're conditioned to feel like it's 5 minutes of human idle time for the session. They don't warn you that the same 5 minute rule applies to tool calls, and I'd suspect longer-running delegations to subagents.

Re: Changes in the system prompt between Claude Opus 4.6 and 4.7

#173

Post by dannyw » Mon, Apr 20, 2026, 5:48 AM UTC

wongarsu wrote: post #123

clickety_clack wrote: post #80

Earlier quoted context omitted.

You can train a tokenizer on old data just like you can train a model on old data.

But you can't use an old model with a new tokenizer. Changing the tokenizer implies you trained the model from scratch

A little bit of post-training will fix that. Folks on /r/LocalLLaMa have been making effective finetunes with diff. tokenizers for years.

Re: Changes in the system prompt between Claude Opus 4.6 and 4.7

#174

Post by renewiltord » Mon, Apr 20, 2026, 5:49 AM UTC

echelon wrote: post #60

rzmmm wrote: post #48

Earlier quoted context omitted.

The alignment favors supporting healthy behaviors so it can be a thin line. I see the system prompt as "plan B" when they can't achieve good results in the training itself. It's a particularly sensitive issue so they are just probably being cautious.

I want a hyperscaler LLM I can fine tune and neuter. Not a platform or product. Raw weights hooked up to pure tools. This era of locked hyperscaler dominance needs to end. If a third tier LLM company made their weights available and they were within 80% of Opus, and they forced you to use their platform to deploy or license if you ran elsewhere, I'd be fine with that. As long as you can access and download the full r…

Yeah, same. So long as they give me everything and cannot enforce their license I don’t mind if they require a license. Ideally the weights should be available even if I only ever run inference once (or perhaps no times). I’m willing to pay 0.99€ for this - lifetime of course.

Re: Changes in the system prompt between Claude Opus 4.6 and 4.7

#175

Post by fnord123 » Mon, Apr 20, 2026, 6:01 AM UTC

gck1 wrote: post #56

embedding-shape wrote: post #6

> The new section includes: When a request leaves minor details unspecified, the person typically wants Claude to make a reasonable attempt now, not to be interviewed first. Uff, I've tried stuff like these in my prompts, and the results are never good, I much prefer the agent to prompt me upfront to resolve that before it "attempts" whatever it wants, kind of surprised to see that they added that

I even have a specific, non-negotiable phase in the process where model MUST interview me, and create an interview file with everything captured. Plan file it produces must always include this file as an artifact and interview takes the highest precedence. Otherwise, the intent gets lost somewhere in the chat transcript.

Are these your own skills files or are you using something off the shelf like bmad or specify-kit?

Re: Changes in the system prompt between Claude Opus 4.6 and 4.7

#176

Post by stingraycharles » Mon, Apr 20, 2026, 6:04 AM UTC

cowlby wrote: post #170

I'm fascinated that Anthropic employees, who are supposed to be the LLM experts, are using tricks like these which go against how LLMs seem to work. Key example for me was the "malware" tool call section that included a snippet with intent "if it's malware, refuse to edit the file". Yet because it appears dozens of times in a convo, eventually the LLM gets confused and will refuse to edit a file that is not malware.…

These aren't as much tricks as just one layer of defense. But prompting is useless, as you can use the API directly without these prompts.

I run claude code with my own system prompt and toolings on top of it. tweakcc broke too often and had too many glitches.

Re: Changes in the system prompt between Claude Opus 4.6 and 4.7

#177

Post by esperent » Mon, Apr 20, 2026, 6:05 AM UTC

jrvarela56 wrote: post #169

The past month made me realize I needed to make my codebase usable by other agents. I was mainly using Claude Code. I audited the codebase and identified the points where I was coupling to it and made a refactor so that I can use either codex, gemini or claude. Here are a few changes: 1. AGENTS.md by default across the codebase, a script makes sure CLAUDE.md symlink present wherever there's an AGENTS.md file 2. Skill…

I've been doing the same except that I'm done with Claude. Cancelled my subscription. I can't use a tool where the limits vary so wildly week to week, or maybe even day to day.

So I'm migrating to pi. I realized that the hardest thing to migrate is hooks - I've built up an expensive collection of Claude hooks over the last few months and unlike skills, hooks are in Claude specific format. But I'd heard people say "just tell the agent to build an extension for pi" so I did. I pointed it at the Claude hooks folder and basically said make them work in pi, and it, very quickly.

Re: Changes in the system prompt between Claude Opus 4.6 and 4.7

#178

Post by stingraycharles » Mon, Apr 20, 2026, 6:10 AM UTC

xpct wrote: post #160

stingraycharles wrote: post #133

Earlier quoted context omitted.

You do realize that similar biases are also present in the training data?

Sure, but now we have to remodel whatever bias we want for our use case with every new release because the system prompt changes, whereas the underlying data does not.

Underlying data changes all the time, as do training methodologies / preferences.

You do realize that these LLMs are trained with a metric ton of synthetic examples? You describe the kind of examples / behavior you want, let it generate thousands of examples of this behavior (positive and negative), and you feed that to the training process.

So changing this type of data is cheap to change, and often not even stored (one LLM is generating examples while the other is training in real-time).

Here's a decent collection of papers on the topic: https://github.com/pengr/LLM-Synthetic-Data

Re: Changes in the system prompt between Claude Opus 4.6 and 4.7

#179

Post by dockerd » Mon, Apr 20, 2026, 6:13 AM UTC

jrvarela56 wrote: post #169

The past month made me realize I needed to make my codebase usable by other agents. I was mainly using Claude Code. I audited the codebase and identified the points where I was coupling to it and made a refactor so that I can use either codex, gemini or claude. Here are a few changes: 1. AGENTS.md by default across the codebase, a script makes sure CLAUDE.md symlink present wherever there's an AGENTS.md file 2. Skill…

How do you share the context/progress of goal across agents?

Re: Changes in the system prompt between Claude Opus 4.6 and 4.7

#180

Post by jrvarela56 » Mon, Apr 20, 2026, 6:48 AM UTC

esperent wrote: post #177

jrvarela56 wrote: post #169

The past month made me realize I needed to make my codebase usable by other agents. I was mainly using Claude Code. I audited the codebase and identified the points where I was coupling to it and made a refactor so that I can use either codex, gemini or claude. Here are a few changes: 1. AGENTS.md by default across the codebase, a script makes sure CLAUDE.md symlink present wherever there's an AGENTS.md file 2. Skill…

I've been doing the same except that I'm done with Claude. Cancelled my subscription. I can't use a tool where the limits vary so wildly week to week, or maybe even day to day. So I'm migrating to pi. I realized that the hardest thing to migrate is hooks - I've built up an expensive collection of Claude hooks over the last few months and unlike skills, hooks are in Claude specific format. But I'd heard people say "ju…

I'm leaning in this direction. Recently slopforked pi to python and created a version that's basically a loop, an LLM call to openrouter and a hook system using pluggy. I have been able to one-shot pretty much any feature a coding agent has. Still toy project but this thread seems to be leading me towards mantaining my own harness. I have a feeling it will be just documenting features in other systems and maintaining evals/tests.