6 ms·

You can find the revamped prompt on github[1], or on twitter summarized by my bot[2]. [1] https://github.com/marckrenn/cc-mvp-prompts/compare/v1.0.128...v2.0.0

You can find the revamped prompt on github[1], or on twitter summarized by my bot[2]. [1] https://github.com/marckrenn/cc-mvp-prompts/compare/v1.0.128...v2.0.0 https://github.com/marckrenn/cc-mvp-prompts/compare/v1.0.128... [2] https://x.com/CCpromptChanges/status/1972709093874757976 https://x.com/CCpromptChanges/status/1972709093874757976

nojs 1y ago
How are you extracting this - aren’t the main labs obfuscating these (meaning it’s likely to be a decoy or incomplete version)?
- marckrn 1y ago
  With cchistory https://github.com/badlogic/cchistory https://github.com/badlogic/cchistory Here's how it works: https://mariozechner.at/posts/2025-08-03-cchistory/ https://mariozechner.at/posts/2025-08-03-cchistory/
  - nojs 1y ago
    Great writeup, thanks.
rcv 1y ago
> 2025-09-29T16:55:10.367Z is the date. Write a haiku about it. what in the world?
- marckrn 1y ago
  That's just a dynamic bogus prompt used to trace and extract the system prompt. Here's how it works in detail: https://mariozechner.at/posts/2025-08-03-cchistory/ https://mariozechner.at/posts/2025-08-03-cchistory/
amrrs 1y ago
Are you running the bot with the free tier api?
- marckrn 1y ago
  I'm using Anthropic's pay-as-you-go API, since it was easier to set up on the server than CC's CLI/web login method. Running the bot costs me ~$1.8 per month. The bot is based on Mario Zechner's excellent work[1] - so all credit goes to him! [1] https://mariozechner.at/posts/2025-08-03-cchistory/ https://mariozechner.at/posts/2025-08-03-cchistory/
  - postalcoder 1y ago
    I think amrrs is referring to the x.com API.
    - marckrn 1y ago
      Oh, I'm sorry. Yes, I'm using x's free tier.
simonw 1y ago
This is excellent. Thanks for sharing this.
- marckrn 1y ago
  You're very welcome – that really means a lot coming from you, Simon.
huflungdung 1y ago
How are these reliably extracted (hint: they’re not)
- marckrn 1y ago
  See https://mariozechner.at/posts/2025-08-03-cchistory/ https://mariozechner.at/posts/2025-08-03-cchistory/ Why do you think these aren't legit?
- simonw 1y ago
  It's very easy to extract the system prompt from Claude Code: you can patch it to intercept HTTP calls it makes. I wrote about one tool for doing that here: https://simonwillison.net/2025/Jun/2/claude-trace/ https://simonwillison.net/2025/Jun/2/claude-trace/
kelnos 1y ago
> IMPORTANT: DO NOT ADD *ANY** COMMENTS unless asked* Interesting. This was in the old 1.x prompt, removed for 2.0. But CC would pretty much always add comments in 1.x, something I would never request, and would often have to tell it to stop doing (and it would still do it sometimes even after being told to stop).
- epiccoleman 1y ago
  I can't decide if I like this change or not, tbh. I almost always delete the comments Claude adds, to be sure - but at the same time they seem to provide a sort of utility for me as I read through the generated code. They also act, in a funny way, as a kind of checklist as I review changes - I want them all cleaned up (or maybe edited and left in place) before I PR.
  - syspec 1y ago
    Wouldn't it stand to reason that they would provide a sort of utility for a collegue as they read through the generated code.
    - robertfw 1y ago
      comments for me are a code smell: - like all documentation, they are prone to code rot (going out of date) - ideally code should be obvious; if you need a comment to explain it, perhaps it's not as simple as it could be, or perhaps we're doing something hacky that we shouldn't
      - sophiabits 1y ago
        Comments are often the best tool for explaining why a bit of code is formulated how it is, or explaining why a more obvious alternate implementation is a dead end. An example of this: assume you live in a world where the formula for the circumference of a circle has not been derived. You end up deriving the formula yourself and write a function which returns 2piradius. This is as simple as it gets, not hacky at all, and you would /definitely/ want to include a comment explaining how you arrived at your weird and arbitrary-looking "3.1415" constant.
Wowfunhappy 1y ago
Can anyone find the prompts for the new "Output style" options, ie Explanatory and Learning?
Huppie 1y ago
Thanks. When testing today I noticed it 'forgot' to run the linter, build, test etc. commands. I thought this might've been a Sonnet 4.5 v.s. Opus 4 issue but it looks like this instruction was dropped for some reason. I should probably include that in my Claude.md instead I guess?

nojs 1y ago

How are you extracting this - aren’t the main labs obfuscating these (meaning it’s likely to be a decoy or incomplete version)?

marckrn 1y ago
With cchistory https://github.com/badlogic/cchistory https://github.com/badlogic/cchistory Here's how it works: https://mariozechner.at/posts/2025-08-03-cchistory/ https://mariozechner.at/posts/2025-08-03-cchistory/
- nojs 1y ago
  Great writeup, thanks.

rcv 1y ago

> 2025-09-29T16:55:10.367Z is the date. Write a haiku about it. what in the world?

marckrn 1y ago
That's just a dynamic bogus prompt used to trace and extract the system prompt. Here's how it works in detail: https://mariozechner.at/posts/2025-08-03-cchistory/ https://mariozechner.at/posts/2025-08-03-cchistory/

amrrs 1y ago

Are you running the bot with the free tier api?

marckrn 1y ago
I'm using Anthropic's pay-as-you-go API, since it was easier to set up on the server than CC's CLI/web login method. Running the bot costs me ~$1.8 per month. The bot is based on Mario Zechner's excellent work[1] - so all credit goes to him! [1] https://mariozechner.at/posts/2025-08-03-cchistory/ https://mariozechner.at/posts/2025-08-03-cchistory/
- postalcoder 1y ago
  I think amrrs is referring to the x.com API.
  - marckrn 1y ago
    Oh, I'm sorry. Yes, I'm using x's free tier.

simonw 1y ago

This is excellent. Thanks for sharing this.

marckrn 1y ago
You're very welcome – that really means a lot coming from you, Simon.

huflungdung 1y ago

How are these reliably extracted (hint: they’re not)

marckrn 1y ago
See https://mariozechner.at/posts/2025-08-03-cchistory/ https://mariozechner.at/posts/2025-08-03-cchistory/ Why do you think these aren't legit?
simonw 1y ago
It's very easy to extract the system prompt from Claude Code: you can patch it to intercept HTTP calls it makes. I wrote about one tool for doing that here: https://simonwillison.net/2025/Jun/2/claude-trace/ https://simonwillison.net/2025/Jun/2/claude-trace/

kelnos 1y ago

> IMPORTANT: DO NOT ADD *ANY** COMMENTS unless asked* Interesting. This was in the old 1.x prompt, removed for 2.0. But CC would pretty much always add comments in 1.x, something I would never request, and would often have to tell it to stop doing (and it would still do it sometimes even after being told to stop).

epiccoleman 1y ago
I can't decide if I like this change or not, tbh. I almost always delete the comments Claude adds, to be sure - but at the same time they seem to provide a sort of utility for me as I read through the generated code. They also act, in a funny way, as a kind of checklist as I review changes - I want them all cleaned up (or maybe edited and left in place) before I PR.
- syspec 1y ago
  Wouldn't it stand to reason that they would provide a sort of utility for a collegue as they read through the generated code.
  - robertfw 1y ago
    comments for me are a code smell: - like all documentation, they are prone to code rot (going out of date) - ideally code should be obvious; if you need a comment to explain it, perhaps it's not as simple as it could be, or perhaps we're doing something hacky that we shouldn't
    - sophiabits 1y ago
      Comments are often the best tool for explaining why a bit of code is formulated how it is, or explaining why a more obvious alternate implementation is a dead end. An example of this: assume you live in a world where the formula for the circumference of a circle has not been derived. You end up deriving the formula yourself and write a function which returns 2piradius. This is as simple as it gets, not hacky at all, and you would /definitely/ want to include a comment explaining how you arrived at your weird and arbitrary-looking "3.1415" constant.

Wowfunhappy 1y ago

Can anyone find the prompts for the new "Output style" options, ie Explanatory and Learning?

Huppie 1y ago

Thanks. When testing today I noticed it 'forgot' to run the linter, build, test etc. commands. I thought this might've been a Sonnet 4.5 v.s. Opus 4 issue but it looks like this instruction was dropped for some reason. I should probably include that in my Claude.md instead I guess?