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Show HN: Uncurl.dev – Convert curl commands to a shareable, executable UI
Hey HN,
I built uncurl.dev to scratch my own itch: I kept getting curl commands in API docs, bug reports, or Slack messages and wanted a quick way to visualize, run, and debug them without firing up Postman or writing code to dissect them. It was also sometimes painful to create a test page specifically for non-tech users to consume an API. I originally vibe-coded this over a weekend just to make it easier for myself to debug API requests shared as curl commands. It slowly grew into something I found surprisingly useful in my workflow, so I decided to clean it up and share it.
uncurl.dev takes a curl command and:
- Converts it into a visual representation
- Lets you edit and inspect all parts of the request
- Allows sharing via a unique link
- (Optionally) executes it from the server, so business or non-technical users can see results
Execution is currently behind login, with a cap (5/min) to avoid abuse and manage costs. Non-logged-in users can still build and share curl commands—they just can’t execute them. The server runs each request in a Docker sandbox with strict resource/time limits (cpu, memory, timeout, no network access outside the request).
It’s not meant to replace full-featured tools like Postman or Hoppscotch. It’s more of a “CLI-to-UI bridge” for fast sharing and debugging, especially in dev workflows where curl is the starting point. Think of it like Pastebin or JSFiddle, but for curl commands.
If you’ve ever copied a curl from an API doc and wanted a cleaner way to see it or send it to someone else, I’d love your feedback.
Thanks!
(You can try it without signup here: https://uncurl.dev https://uncurl.dev)
- polishdude20 1y agoWhy the need for an account to execute? Are you executing the command on behalf of the user on your server? Is it possible to just do it locally in browser?
- zamadatix 1y agoThe post mentions the server is used during the optional execution. My guess as to why would be primarily because there are plenty of curl commands which are impossible to execute via the browser due to browser restrictions and secondarily because the execution is literally running curl, not trying to approximate the equivalent action. Local execution could still be a handy feature for at least the most common basic commands though, but it'd start to have to wade into "explaining a lot to the user why this isn't really what the result might look like" territory.
- VWWHFSfQ 1y agoIt actually looks like the server is used regardless. It's sending the full curl command to the backend even if not executing it.
- zamadatix 1y agoWell yeah, it's generating short links. I mean to highlight the server runs curl in a sandbox against the 3rd party host on behalf of the user, not just that the server and client talk to each other as you use the page.
- darubramha 1y agoYes — executions are done server-side, inside a resource-limited, sandboxed Docker container. That’s why login is required: to prevent abuse, rate-limit usage. I have a feature working to allow users browser side execution, but as others have also pointed out CORS is a big blocker for client side execution not working for all APIs.
- h1fra 1y agoInteresting. Default behavior could be improved. I blindly pasted a curl, except showing my curl it didn't make any headers modifiable. It also didn't redacted the Authorization header. Also there is no way to delete a page.
- serial_dev 1y agoWhether redacting the auth header is the best choice can be determined on a case by case basis, so I don't think it should redact by default. A big scary warning would definitely make sense, though!
- byearthithatius 1y agoExact same thing happened to me. Had to reset my HN user cookie because accidentally pasted my downvote curl command.
- markerz 1y agoFYI, you can delete anyone's CURL (including your own if you were unauthenticated) with the following curl: https://uncurl.dev/curl/78ab4bf5-34e8-45a0-b3b1-32dd6aa7e360 https://uncurl.dev/curl/78ab4bf5-34e8-45a0-b3b1-32dd6aa7e360 or this command curl -X DELETE "https://uncurl.dev/api/curls?id=051606b5-49c8-4f14-9689-4d424f71d331" Looks like deletes are unauthenticated.
- darubramha 1y agoHaha love that you shared the curl with the uncurl.dev url! Yes, delete is unauthenticated as highlighted, will be working on a fix for this. And you can delete any API if it is created as a logged in user.
- deleted 1y ago[deleted]
- niek_pas 1y agoLooks cool! One bug I found: `curl www.google.com` works using 8.7.1 on macOS, but I get "Please enter a valid curl command" on your website.
- darubramha 1y ago:) the curl command parser expects some flags of GET, POST, stupidly overlooked, will get it fixed!
- ajnin 1y agoHum I'm definitely not the target for this but I don't see the value to obfuscate all the info in an UUID, I'd have kept things simple and stored things into an URL fragment, that way it's possible to operate client-side only and nothing gets leaked to a server I don't know much about like headers or whatever tokens or API keys could be passed in an URL.
- aae42 1y agocould also just do the request in javascript instead of needing a (presumably hosted) sandbox
- ultrafez 1y agoThere are many types of request that cannot be made with client-side JS alone, but for those that can, the ability to send those requests client-side would be handy.
- markerz 1y agoI think that 99.9% of CURL commands are copied from Chrome/Firefox's network inspector and are the simple "client-side JS" types. I also think it's weird to be so willing to let people run arbitrary CURL commands from your platform, without any billing or account verification. It feels ripe for abuse.
- jasir 1y agoEven for commands that use the subset of cURL features that fetch supports, most requests to other domains (cross origin requests) wouldn't work anyway because the responses won't have the CORS[0] headers to allow being accessed from arbitrary websites. So running it client side would be infeasible for most requests. [0]: https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/CORS https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/COR...
- darubramha 1y ago
- Tabular-Iceberg 1y agoIt seems very particular about what curl options it supports. I keep getting “Please enter a valid curl command” no matter what I do. Maybe the only solution is to somehow extract the actual command line parser from curl itself.
- darubramha 1y agoHey that is weird, can you file a bug report here with the curl you were trying? https://github.com/uncurl/uncurl-support https://github.com/uncurl/uncurl-support
- VWWHFSfQ 1y agoThis would be useful if it was client-side only. I only very rarely have curl commands to run that don't also include some stuff like cookies and tokens, which I'm not sending to someone's server so they can run curl for me.
- cgannett 1y agoI cant even get the thing to work
- byearthithatius 1y agoMultiple people already did and are confirming they can't even delete it. This website is literally a security issue itself.
- darubramha 1y agoHey, you can absolutely delete any curls created if done from a logged in user, for others it will get auto-purged in 30 days of non-usage.
- treesknees 1y agoThis is why in our codebase we have a rule to not use short options/flags for called commands like curl. And if there is only a short option available, it must be explained in a code comment.
- xrisk 1y agoWhy do you call curl via the binary instead of using libcurl?
- notpushkin 1y agoBash scripts?
- markerz 1y agoDocker files too, basically just bash scripts with a different syntax
- treesknees 1y agoAs others stated, shell scripts and some other automation that have to call the cli tool directly, or where we need to build out the cmd and execute it on a remote node. We use libcurl and pycurl where it makes sense. This rule for cli options extends to other binaries as well, some that don’t offer libraries like curl does (think closed source firmware tools or ancient homegrown cli tools.)
- deleted 1y ago[deleted]
- flipperto 1y agoWhile it looks good and even possibly useful, it seems to be a great way to leak sensitive cookies (especially since "copy as cURL" is so easy on the browser's network tab). I would 100% forbid its use in a company environment and I would encourage people in general not to use it for any non-trivial use case.
- byearthithatius 1y agoThank you. I literally already accidentally uploaded a cookie that I now need to reset because the website doesn't let me delete the curl -_-
- ustad 1y agoHey, that looks great. Could you describe more about the docker sandbox that you have? I am especially interested in the network restrictions.
- darubramha 1y agoThe sandbox is a lightweight Alpine-based container, it runs as a non-root user for security, it has minimal dependencies installed (curl, bash, coreutils) The container has restricted outbound access—only HTTP/S requests are allowed. It runs inside an isolated network namespace with no access to the host network or other infrastructure components. There's no inbound access, and the container can't receive unsolicited requests from the outside world. The sandbox container can only communicate with other containers in the same network, the main application container and sandbox container are on the same network, allowing them to communicate.
- ustad 1y agoThanks for the details! Do you think there could be ways for someone to abuse the network setup you have? For example, accessing other internet hosts or other containers in the same container network? What happens when curl gets redirect responses?
- benoitg 1y agoThe Jetbrains suite of IDEs have this handy feature : if you copy a curl command into an HTTP scratch file, it is automatically converted to the HTTP equivalent, which is IMHO much more readable. Your project looks very cool though, and expands on the share aspect of the Jetbrains feature, very interesting!
- _kidlike 1y agomy thoughts exactly! Lately I feel like a lot of people think they are finding gaps around developer experience, but it's only because they don't know the right tools that already exist...
- hk1337 1y agoPaw (Now RapidAPI) has a nice feature that generates a http request. The curl plugin and http plugin are the main ones I use but there's several others to generate the code in other languages too.
- darubramha 1y agoAppreciate the kind words—and the comparison! uncurl.dev kind of grew out of that same spirit, but with the goal of making the output shareable and executable in a browser, especially for folks who might not have an IDE set up or are outside the usual dev loop (PMs, etc.)
- fitsumbelay 1y agoThis is a pretty cool project. One thing: it's rejecting dict lookups as invalid URL, eg. `curl dict://dict.org/d:failure:fd-eng-fra` I'm checking first here whether I missed something in the docs about not supporting DICT before I add issue to the GH repo
- darubramha 1y agoYou didn’t miss anything in the docs. Right now uncurl.dev only supports http/https (and technically ftp, though it’s untested). Protocols like dict://, smtp://, etc. aren’t parsed or handled correctly yet, which is why you’re seeing that “invalid URL” error. I hadn’t actually considered dict:// usage, I see the bug report as well, thanks, will see if I can include it.
- lenkite 1y agoFeels like a security nightmare - this is far better distributed as a local desktop UI rather than one hosted.
- byearthithatius 1y agoIt 100% is because he just keeps your curl and you can't even delete it. He just keeps it forever for himself even if you made a whoops. Already accidentally uploaded my HN user cookie and had to reset it. JFC.... -_-
- thomasfromcdnjs 1y agolmao I did similar.
- darubramha 1y agoI have implemented auto-purge all curls that are created without login will get auto deleted after 30 days of non-usage. You can absolutely delete your curl if you have created as a logged in user.
- byearthithatius 1y agoI already accidentally uploaded a cookie that I now need to reset because the website doesn't let me delete the curl -_-
- markerz 1y agoDefinitely reset your password/account even if you can delete it from their website. Otherwise, you are trusting a stranger with no privacy policy or reputation.
- byearthithatius 1y agoGreat point, true!
- dwrowe 1y agoThere is both this post about not being able to delete a curl, and other posts about being able to delete curls unauthenticated. Looks like you should be able to issue a DELETE curl request, to delete your curl.
- darubramha 1y agoYou can delete the curl request if created from a logged in account. Non-logged in curls are auto purged after 30 days.
- byearthithatius 1y agoThis is just waiting for people to leak cookies oh my lord....
- trollied 1y agoFlagged this because it is a security clusterfuck.
- darubramha 1y agoFair. I appreciate the honesty — even if it's a bit brutal :) Security is a top priority for this project, and I'm actively working to tighten things up. This initial version was launched to validate the concept, and admittedly, there were oversights (including an unauthenticated DELETE endpoint that was highlighted). If you're open to it, I'd love to learn more about what you'd want to see from a security standpoint in a tool like this. I'm building in public and happy to be corrected where needed. Thanks again for keeping things real.
- markerz 1y agoHey OP, your DELETE curl endpoint is unauthenticated! I can't DM you on HN and there's no contact on your website, so sorry for the public security disclosure. :(
- mzronek 1y agoThat's part of the vibe in vibe coding.
- reassess_blind 1y agoV.I.B.E - Very Insecure Backend Endpoint
- darubramha 1y agoHey, thank you so much for catching this and calling it out , will take this up and fix it! Really appreciate you taking the time to look and let me know (even if it had to be in public). I have added a github repo for filing bugs (https://github.com/uncurl/uncurl-support https://github.com/uncurl/uncurl-support) in the docs page :)