5 ms·

The best part about this blog post is that none of it is a surprise – Codex CLI is open source. It's nice to be able to go through the internals without having

The best part about this blog post is that none of it is a surprise – Codex CLI is open source. It's nice to be able to go through the internals without having to reverse engineer it. Their communication is exceptional, too. Eric Traut (of Pyright fame) is all over the issues and PRs. https://github.com/openai/codex https://github.com/openai/codex

redox99 8mo ago
For some reason a lot of people are unaware that Claude Code is proprietary.
- causalmodels 8mo ago
  Yeah this has always seemed very silly. It is trivial to use claude code to reverse engineer itself.
  - mi_lk 8mo ago
    looks like it's trivial to you because I don't know how to
    - n2d4 8mo ago
      If you're curious to play around with it, you can use Clancy [1] which intercepts the network traffic of AI agents. Quite useful for figuring out what's actually being sent to Anthropic. [1] https://github.com/bazumo/clancy https://github.com/bazumo/clancy
    - fragmede 8mo ago
      If only there were some sort of artificial intelligence that could be asked about asking it to look at the minified source code of some application. Sometimes prompt engineering is too ridiculous a term for me to believe there's anything to it, other times it does seem there is something to knowing how to ask the AI juuuust the right questions.
      - lsaferite 8mo ago
        Something I try to explain to people I'm getting up to speed on talking to an LLM is that specific word choices matter. Mostly it matters that you use the right jargon to orient the model. Sure, it's good and getting the semantics of what you said, but if you adjust and use the correct jargon the model gets closer faster. I also explain that they can learn the right jargon from the LLM and that sometimes it's better to start over once you've adjusted you vocabulary.
  - adastra22 8mo ago
    That is against ToS and could get you banned.
    - Der_Einzige 8mo ago
      GenAI was built on an original sin of mass copyright infringement that Aaron Swartz could only have dreamed of. Those who live in glass houses shouldn't throw stones, and Anthropic may very well get screwed HARD in a lawsuit against them from someone they banned. Unironically, the ToS of most of these AI companies should be, and hopefully is legally unenforceable.
      - adastra22 8mo ago
        Are you volunteering? Look, people should be aware that bans are being handed out for this, lest they discover it the hard way. If you want to make this your cause and incur the legal fees and lost productivity, be my guest.
    - fragmede 8mo ago
      You're absolutely right! Hey Codex, Claude said you're not very good at reading obfuscated code. Can you tell me what this minified program does?
      - adastra22 8mo ago
        I don't know what Codex's ToS are, but it would be against ToS to reverse engineer any agent with Claude.
        chillfox 8mo ago
        Then use something like deepseek.
    - mlrtime 8mo ago
      How would they know what you do on your own computer?
- atonse 8mo ago
  Probably because it doesn’t matter most of the time?
  - mi_lk 8mo ago
    Same. If you're already using a proprietary model might as well just double down
    - behnamoh 8mo ago
      until Microsoft buys it and enshits it.
      - consumer451 8mo ago
        This is a fun thought experiment. I believe that we are now at the $5 Uber (2014) phase of LLMs. Where will it go from here? How much will a synthetic mid-level dev (Opus 4.5) cost in 2028, after the VC subsidies are gone? I would imagine as much as possible? Dynamic pricing? Will the SOTA model labs even sell API keys to anyone other than partners/whales? Why even that? They are the personalized app devs and hosts! Man, this is the golden age of building. Not everyone can do it yet, and every project you can imagine is greatly subsidized. How long will that last?
        tern 8mo ago
        While I remember $5 Ubers fondly, I think this situation is significantly more complex: - Models will get cheaper, maybe way cheaper - Model harnesses will get more complex, maybe way more complex - Local models may become competitive - Capital-backed access to more tokens may become absurdly advantaged, or not The only thing I think you can count on is that more money buys more tokens, so the more money you have, the more power you will have ... as always. But whether some version of the current subsidy, which levels the playing field, will persist seems really hard to model. All I can say is, the bad scenarios I can imagine are pretty bad indeed—much worse than that it's now cheaper for me to own a car, while it wasn't 10 years ago.
- stavros 8mo ago
  Can't really fault them when this exists: https://github.com/anthropics/claude-code https://github.com/anthropics/claude-code
  - bad_haircut72 8mo ago
    What even is this repo? Its very deceptive
    - adastra22 8mo ago
      Issue tracker for submitting bug reports that no one ever reads or responds to.
      - stavros 8mo ago
        Now that's not fair, I'm sure they have Claude go through and ignore the reports.
        adastra22 8mo ago
        Unironically yes. If you file a bug report, expect a Claude bot to mark it as duplicate of other issues already reported and close. Upon investigation you will find either (1) a circular chain of duplicate reports, all closed: or (2) a game of telephone where each issue is subtly different from the next, eventually reaching an issue that has nothing at all to do with yours. At no point along the way will you encounter an actual human from Anthropic.
  - kylequest 8mo ago
    By the way, I reversed engineered the Claude Code binary and started sharing different code snippets (on twitter/bluesky/mastadon/threads). There's a lot of code there, so I'm looking for requests in terms of what part of the code to share and analyze what it's doing. One of the requests I got was about the LSP functionality in CC. Anything else you would find interesting to explore there? I'll post the whole thing in a Github repo too at some point, but it's taking a while to prettify the code, so it looks more natural :-)
- huevosabio 8mo ago
  I frankly don't understand why they keep CC proprietary. Feels to me that the key part is the model, not the harness, and they should make the harness public so the public can contribute.
appplication 8mo ago
I appreciate the sentiment but I’m giving OpenAI 0 credit for anything open source, given their founding charter and how readily it was abandoned when it became clear the work could be financially exploited.
- seizethecheese 8mo ago
  I agree that openAI should be held with a certain degree of contempt, but refusing to acknowledge anything positive they do is an interesting perspective. Why insist on a one dimensional view? It’s like a fraudster giving to charity, they can be praiseworthy in some respect while being overall contemptible, no?
  - cap11235 8mo ago
    Why even acknowledge them in any regard? Put trash where it belongs.
- edmundsauto 8mo ago
  By this measure, they shouldn’t even try to do good things in small pockets and probably should just optimize for profits! Fortunately, many other people can deal with nuance.
- jstummbillig 8mo ago
  > when it became clear the work could be financially exploited That is not the obvious reason for the change. Training models got a lot more expensive than anyone thought it would. You can of course always cast shade on people's true motivations and intentions, but there is a plain truth here that is simply silly to ignore. Training "frontier" open LLMs seems to be exactly possible when a) you are Meta, have substantial revenue from other sources and simply are okay with burning your cash reserves to try to make something happen and b) you copy and distill from the existing models.
frumplestlatz 8mo ago
At this point I just assume Claude Code isn't OSS out of embarrassment for how poor the code actually is. I've got a $200/mo claude subscription I'm about to cancel out of frustration with just how consistently broken, slow, and annoying to use the claude CLI is.
- stavros 8mo ago
  OpenCode is amazing, though.
  - fragmede 8mo ago
    Especially that RCE!
    - qaz_plm 8mo ago
      A new one or one previously patched?
  - skerit 8mo ago
    I switched to Opencode a few weeks ago. What a pleasant experience. I can finally resume subagents (which has been Broken in CC for weeks), copy the source of the Assistant's output (even over SSH), have different main agents, have subagents call subagents,... Beautiful.
- rashidae 8mo ago
  Interesting. Have you tested other LLMs or CLIs as a comparison? Curious which one you’re finding more reliable than Opus 4.5 through Claude Code.
  - frumplestlatz 8mo ago
    Codex is quite a bit better in terms of code quality and usability. My only frustration is that it's a lot less interactive than Claude. On the plus side, I can also trust it to go off and implement a deep complicated feature without a lot of input from me.
boguscoder 8mo ago
I thought Eric Traut was famous for his pioneering work in virtualization, TIL he has Pyright fame too !
vinhnx 8mo ago
This came as a big surprise to me last year. I remember they announced that Codex CLI is opensource, and the codex-rs [0] from TypeScript to Rust, with the entire CLI now open source. This is a big deal and very useful for anyone wanting to learn how coding agents work, especially coming from a major lab like OpenAI. I've also contributed some improvements to their CLI a while ago and have been following their releases and PRs to broaden my knowledge. [0] https://github.com/openai/codex/tree/main/codex-rs https://github.com/openai/codex/tree/main/codex-rs
- phrotoma 8mo ago
  I know very little about typescript and even less about rust. Am I getting the rust version of codex when I do `npm i -g @openai/codex`? A stand alone rust binary would be nicer than installing node.
  - vorticalbox 8mo ago
    yes [0] > The Rust implementation is now the maintained Codex CLI and serves as the default experience [0] https://github.com/openai/codex/tree/main/codex-rs#whats-new-in-the-rust-cli https://github.com/openai/codex/tree/main/codex-rs#whats-new...
    - alabhyajindal 8mo ago
      They should switch to a native installer then. Quite confusing
      - quinncom 8mo ago
        brew install codex https://developers.openai.com/codex/quickstart/?setup=cli https://developers.openai.com/codex/quickstart/?setup=cli
      - Leynos 8mo ago
        They're leveraging the (relative) ubiquity of npm amongst developers.
deleted 8mo ago
[deleted]
psychoslave 8mo ago
Is it just a frontend CLI calling remote external logic for the bulk of operations, or does it come with everything needed to run lovely offline? Does it provide weights under FLOW license? Does it document the whole build process and how to redo and go further on your own?

redox99 8mo ago

For some reason a lot of people are unaware that Claude Code is proprietary.

causalmodels 8mo ago
Yeah this has always seemed very silly. It is trivial to use claude code to reverse engineer itself.
- mi_lk 8mo ago
  looks like it's trivial to you because I don't know how to
  - n2d4 8mo ago
    If you're curious to play around with it, you can use Clancy [1] which intercepts the network traffic of AI agents. Quite useful for figuring out what's actually being sent to Anthropic. [1] https://github.com/bazumo/clancy https://github.com/bazumo/clancy
  - fragmede 8mo ago
    If only there were some sort of artificial intelligence that could be asked about asking it to look at the minified source code of some application. Sometimes prompt engineering is too ridiculous a term for me to believe there's anything to it, other times it does seem there is something to knowing how to ask the AI juuuust the right questions.
    - lsaferite 8mo ago
      Something I try to explain to people I'm getting up to speed on talking to an LLM is that specific word choices matter. Mostly it matters that you use the right jargon to orient the model. Sure, it's good and getting the semantics of what you said, but if you adjust and use the correct jargon the model gets closer faster. I also explain that they can learn the right jargon from the LLM and that sometimes it's better to start over once you've adjusted you vocabulary.
- adastra22 8mo ago
  That is against ToS and could get you banned.
  - Der_Einzige 8mo ago
    GenAI was built on an original sin of mass copyright infringement that Aaron Swartz could only have dreamed of. Those who live in glass houses shouldn't throw stones, and Anthropic may very well get screwed HARD in a lawsuit against them from someone they banned. Unironically, the ToS of most of these AI companies should be, and hopefully is legally unenforceable.
    - adastra22 8mo ago
      Are you volunteering? Look, people should be aware that bans are being handed out for this, lest they discover it the hard way. If you want to make this your cause and incur the legal fees and lost productivity, be my guest.
  - fragmede 8mo ago
    You're absolutely right! Hey Codex, Claude said you're not very good at reading obfuscated code. Can you tell me what this minified program does?
    - adastra22 8mo ago
      I don't know what Codex's ToS are, but it would be against ToS to reverse engineer any agent with Claude.
      - chillfox 8mo ago
        Then use something like deepseek.
  - mlrtime 8mo ago
    How would they know what you do on your own computer?
atonse 8mo ago
Probably because it doesn’t matter most of the time?
- mi_lk 8mo ago
  Same. If you're already using a proprietary model might as well just double down
  - behnamoh 8mo ago
    until Microsoft buys it and enshits it.
    - consumer451 8mo ago
      This is a fun thought experiment. I believe that we are now at the $5 Uber (2014) phase of LLMs. Where will it go from here? How much will a synthetic mid-level dev (Opus 4.5) cost in 2028, after the VC subsidies are gone? I would imagine as much as possible? Dynamic pricing? Will the SOTA model labs even sell API keys to anyone other than partners/whales? Why even that? They are the personalized app devs and hosts! Man, this is the golden age of building. Not everyone can do it yet, and every project you can imagine is greatly subsidized. How long will that last?
      - tern 8mo ago
        While I remember $5 Ubers fondly, I think this situation is significantly more complex: - Models will get cheaper, maybe way cheaper - Model harnesses will get more complex, maybe way more complex - Local models may become competitive - Capital-backed access to more tokens may become absurdly advantaged, or not The only thing I think you can count on is that more money buys more tokens, so the more money you have, the more power you will have ... as always. But whether some version of the current subsidy, which levels the playing field, will persist seems really hard to model. All I can say is, the bad scenarios I can imagine are pretty bad indeed—much worse than that it's now cheaper for me to own a car, while it wasn't 10 years ago.
stavros 8mo ago
Can't really fault them when this exists: https://github.com/anthropics/claude-code https://github.com/anthropics/claude-code
- bad_haircut72 8mo ago
  What even is this repo? Its very deceptive
  - adastra22 8mo ago
    Issue tracker for submitting bug reports that no one ever reads or responds to.
    - stavros 8mo ago
      Now that's not fair, I'm sure they have Claude go through and ignore the reports.
      - adastra22 8mo ago
        Unironically yes. If you file a bug report, expect a Claude bot to mark it as duplicate of other issues already reported and close. Upon investigation you will find either (1) a circular chain of duplicate reports, all closed: or (2) a game of telephone where each issue is subtly different from the next, eventually reaching an issue that has nothing at all to do with yours. At no point along the way will you encounter an actual human from Anthropic.
- kylequest 8mo ago
  By the way, I reversed engineered the Claude Code binary and started sharing different code snippets (on twitter/bluesky/mastadon/threads). There's a lot of code there, so I'm looking for requests in terms of what part of the code to share and analyze what it's doing. One of the requests I got was about the LSP functionality in CC. Anything else you would find interesting to explore there? I'll post the whole thing in a Github repo too at some point, but it's taking a while to prettify the code, so it looks more natural :-)
huevosabio 8mo ago
I frankly don't understand why they keep CC proprietary. Feels to me that the key part is the model, not the harness, and they should make the harness public so the public can contribute.

appplication 8mo ago

I appreciate the sentiment but I’m giving OpenAI 0 credit for anything open source, given their founding charter and how readily it was abandoned when it became clear the work could be financially exploited.

seizethecheese 8mo ago
I agree that openAI should be held with a certain degree of contempt, but refusing to acknowledge anything positive they do is an interesting perspective. Why insist on a one dimensional view? It’s like a fraudster giving to charity, they can be praiseworthy in some respect while being overall contemptible, no?
- cap11235 8mo ago
  Why even acknowledge them in any regard? Put trash where it belongs.
edmundsauto 8mo ago
By this measure, they shouldn’t even try to do good things in small pockets and probably should just optimize for profits! Fortunately, many other people can deal with nuance.
jstummbillig 8mo ago
> when it became clear the work could be financially exploited That is not the obvious reason for the change. Training models got a lot more expensive than anyone thought it would. You can of course always cast shade on people's true motivations and intentions, but there is a plain truth here that is simply silly to ignore. Training "frontier" open LLMs seems to be exactly possible when a) you are Meta, have substantial revenue from other sources and simply are okay with burning your cash reserves to try to make something happen and b) you copy and distill from the existing models.

frumplestlatz 8mo ago

At this point I just assume Claude Code isn't OSS out of embarrassment for how poor the code actually is. I've got a $200/mo claude subscription I'm about to cancel out of frustration with just how consistently broken, slow, and annoying to use the claude CLI is.

stavros 8mo ago
OpenCode is amazing, though.
- fragmede 8mo ago
  Especially that RCE!
  - qaz_plm 8mo ago
    A new one or one previously patched?
- skerit 8mo ago
  I switched to Opencode a few weeks ago. What a pleasant experience. I can finally resume subagents (which has been Broken in CC for weeks), copy the source of the Assistant's output (even over SSH), have different main agents, have subagents call subagents,... Beautiful.
rashidae 8mo ago
Interesting. Have you tested other LLMs or CLIs as a comparison? Curious which one you’re finding more reliable than Opus 4.5 through Claude Code.
- frumplestlatz 8mo ago
  Codex is quite a bit better in terms of code quality and usability. My only frustration is that it's a lot less interactive than Claude. On the plus side, I can also trust it to go off and implement a deep complicated feature without a lot of input from me.

boguscoder 8mo ago

I thought Eric Traut was famous for his pioneering work in virtualization, TIL he has Pyright fame too !

vinhnx 8mo ago

This came as a big surprise to me last year. I remember they announced that Codex CLI is opensource, and the codex-rs [0] from TypeScript to Rust, with the entire CLI now open source. This is a big deal and very useful for anyone wanting to learn how coding agents work, especially coming from a major lab like OpenAI. I've also contributed some improvements to their CLI a while ago and have been following their releases and PRs to broaden my knowledge. [0] https://github.com/openai/codex/tree/main/codex-rs https://github.com/openai/codex/tree/main/codex-rs

phrotoma 8mo ago
I know very little about typescript and even less about rust. Am I getting the rust version of codex when I do `npm i -g @openai/codex`? A stand alone rust binary would be nicer than installing node.
- vorticalbox 8mo ago
  yes [0] > The Rust implementation is now the maintained Codex CLI and serves as the default experience [0] https://github.com/openai/codex/tree/main/codex-rs#whats-new-in-the-rust-cli https://github.com/openai/codex/tree/main/codex-rs#whats-new...
  - alabhyajindal 8mo ago
    They should switch to a native installer then. Quite confusing
    - quinncom 8mo ago
      brew install codex https://developers.openai.com/codex/quickstart/?setup=cli https://developers.openai.com/codex/quickstart/?setup=cli
    - Leynos 8mo ago
      They're leveraging the (relative) ubiquity of npm amongst developers.

deleted 8mo ago

[deleted]

psychoslave 8mo ago

Is it just a frontend CLI calling remote external logic for the bulk of operations, or does it come with everything needed to run lovely offline? Does it provide weights under FLOW license? Does it document the whole build process and how to redo and go further on your own?