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Ask HN: Is there a pure SMS based UI?

93 points by joshcramer ↗ HN
I’m traveling to an area of the world where the only communication medium I will have available to me is unlimited 140 character text messages. I’m wondering if it is possible to set up a computer that will allow me to fully interact with it via SMS. I’d like to be able to do things like check the news, read and reply to my emails, check on the status of my home and other servers. What is the state of the art in SMS based human computer interaction?

121 comments

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detaro
not aware of anything universal. There are SMS-based services for lots of things, but less in the context of "UI for my own things".

in lots of ways, it's console UI with additional length limits I guess? Or chatbot-UI.

abrichr
Which part of the world?
joshcramer
Alaska. It is possible to get LEO phone / data, but it is more cost prohibitive. Unlimited SMS plans on LEO satellite services are relatively cheap.
vegardx
Have you tried using these services? It can take anywhere from 5-60 minutes just to send a message. It's a reason they often go from 10-20 messages included in the monthly cost to unlimited for only a few bucks more. You're not going to be sending many. All sending and receiving happens through their proprietary application.
Turing_Machine
I assume we're talking a deep Bush situation, as all but the tiniest villages have regular Internet service nowadays.

Might be worth looking into Starlink, if you haven't already. I know it does have coverage in at least some regions of the state now.

Source: have lived in Alaska for many years.

cupofpython
you might have an easier time splitting up send and receive into separate managed things instead of looking for one system to do it all over SMS

_SEND_

You can send an email over SMS I believe by texting the email address.

So you should be able to set up a server to process emails you send to a specific address and trigger commands in response to it. the triggers would need to be set up in advance, but other than that you should be able to do anything normal

_RECEIVE_

For receiving SMS - I am not sure tbh. You could use Twilio, but it might be overkill. I would jsut make sure whatever solution you use doesn't get automatically blocked by the ISP. I am not sure the proper way to flag something as wanted / intended

judge2020
The main issue with SMS is that it's unencrypted and often intentionally being piped to third party firms for advertising and whatnot, so whatever you do it probably isn't advisable to send anything you wouldn't want people seeing (eg. I wouldn't suggest doing email via it). If you have even the smallest data cap, https://lite.cnn.com can be used for your news and https://mail.google.com/mail/u/0/h/ (/h/ at the end) will load the mostly pure HTML version of Gmail, or even just imap (without automated push/pull) is pretty lightweight on data usage.
Areibman
If this is the case, why do so many apps use SMS for 2FA and sending unique links? Are MITM attacks over SMS common?
Robotbeat
Well… it’s not necessarily a good idea to do 2FA with SMS. Additionally, the codes sent by SMS are usually very time-sensitive, like 5 minutes.

And it means someone has to have compromised both your computer and your SMS in order to defeat the 2FA. Which doesn’t make it impossible. But it’s not trivial to coordinate those things.

judge2020
But, to add, sim swap attacks are a known issue and anything of value becomes a target. The main issue is that retail employees in 'authorized reseller' locations are allowed to make changes to accounts with the PIN of the account holder, but that is often easy to guess or is easy to figure out by anyone that does enough digging into someone's life.

https://www.cnn.com/2020/03/13/tech/sim-hack-million-dollars...

https://youtu.be/caVEiitI2vg?t=145 (tldr he got cold called to set up 'extra security', gave the attacker a PIN number, and the attacker used that to impersonate them within a T-Mobile store and swap the sim card from the phone into a new phone, thus receiving SMS 2fa codes for their accounts).

_wldu
End user convenience.
masswerk
Rather, adminstrative convenience. Mind that SMS-based 2FA replaced one-time pads (TANs), which required physical handling.
snarf21
Most companies suck at security. Most users suck at security. Convenience > Security. It is sad that SMS as 2FA account recovery actually adds an attack vector. It is less bad as an out-of-band check if you have a password authentication from a known and finger printed computer.
ufmace
On the level of individual accounts, SMS has proven to be vulnerable to compromise. These attacks are pretty labor-intensive though. On the level of an app or service, SMS 2FA is still a big net gain in blocking account compromise though. Individual users, especially anyone who is at a particular risk for targeted attacks, would be wise to seek out more secure solutions.
jabroni_salad
because SMS already has near-universal adoption. As much as I love my yubikey I don't know anyone (in the real, not HERE) who uses one for a personal account.
7steps2much
Depending on how important this is to you there is always the option of getting yourself a VOIP number and a softphone on one of your computers and hooking a small script into it to do whatever things you want to acchieve.

Never done anything like this but I imagine that it might not be too hard since the infrastructure is pretty much there already. However building a "protocol" on top of SMS might be somewhat tricky. You might want to write an APP or something for that.

As for "fire and forget" solutions ... Well, there are email to SMS gateways if i remember correctly.

JNRowe
Far from state of the art, but…

I used to have a cheap Huawei dongle connected to my desktop that I'd interact with via awful scripting against gnokii¹. If you're the type of person that likes hacking up your own solutions it can be quite fun to work with.

After a lot of trial and error^wimprovement I found it useful to use gnokii's SMS mailbox export, and run a job to iterate over the exported mailbox periodically. The simple reason being most scripting languages ship with mbox support out of the box, and there are heaps of tools for handling them from a shell script.

¹ http://gnokii.org

BigBalli
Which country will you be in? Can you send international SMS for free?
16
I have a second SIM card that T-Mobile gave me for free (no idea why). I have it installed in an Android phone running Tasker with a bunch of jobs I created to do various things. Android phone stays at home while my primary (flip phone) comes with me. I get specific Matrix (https://matrix.org) messages forwarded to my flip phone, I can query the weather, I have a couple RSS feeds forwarding, and I can enable/disable any of these tasker profiles by sending custom commands from the flip phone back to the android. Obviously this requires having a second SIM card, but you could probably find a super cheap talk/text (or text-only?) prepaid plan temporarily and set up something similar. Tasker is extremely powerful and could conceivably do most if not all of what you're asking.
beaconstudios
you could also use Twilio to build an SMS inbox API and do it without any hardware.
notRobot
That's so cool!

Q: How do you get Tasker to read Matrix messages?

freen
Https://textit.com
jeroenhd
IP packets contain 20 bytes of headers, the rest is data. Theoretically you could create the world's worst VPN by stuffing the 140 bytes of an SMS absolutely full of binary data, with some compression of course.

So I went looking for "IP over SMS" and actually found this: https://github.com/spandanb/ipos but it's for web browsers only. This old HN thread talks about the same concept: https://news.ycombinator.com/item?id=8304409

You could possibly port something like https://github.com/PiMaker/Teletun to SMS instead of using Telegram. The Python TUN API seems quite elegant to work with, if you can get two SMS capable devices running Linux you can probably set up the world's worst wireless AP.

Some students had the same idea and built a proof of concept: https://www.thomasclausen.net/en/nice-student-project-at-eco...

bArray
These requirements sound very similar to something like LoRa, would be worth checking out stuff in that space too.

You could quite viably fetch the latest article from an RSS feed in this space, or reply to an email, even with minimal compression. The less technical the solution is the better.

I would definitely suggest to have some commands built in and have the ability to poll the current state of your service to ensure it's not being abused, etc. You also might need a human the other side to reboot it occasionally, so make it very simple to get back online.

giomasce
I managed to do something useful with iodine (IP over DNS), a couple of times. Performance is abysmal, but a simple SSH session might have some hope. Most web applications are impossible, and for email you must be lucky.
threeio
I remember staying at a hotel in the UK that rented internet in 500MB chunks... i figured out that if I tunneled everything via DNS they didn't count the traffic. I wish I had known about Iodine at that point ;)
threeio
I remember staying at a hotel in the UK that rented internet in 500MB chunks... i figured out that if I tunneled everything via DNS they didn't count the traffic. I wish I had known about Iodine at that point ;)
kurthr
You might also see if you can just restrict interaction to a shell. That's definitely going to be much lower bandwidth (and thus more responsive). Then anything you can do in the shell, you can do through SMS. Updating an 80col screen isn't a completely unreasonable number of messages... especially if you're doing compression.

Security is probably a bigger issue.

PaulHoule
Couldn’t that blow up your phone? I could cat a million line file and it would take some time before I could do the equivalent of ctrl-c or close session.
Spare_account
The agent running on the remote machine would need to be aware of this issue and filter out long responses.
kurthr
Yes, for example, just update the screen no more than once every few seconds. With no compression you can send chained 153 ascii character messages is only 13-14 SMS messages. With any compression, I suspect you could get refresh rates for most commands in less than a second in response to reasonable commands. Unreasonable command responses you could simply ^C or otherwise terminate the script.
roywashere
That is nice but with 'unlimited' SMS will probably get you throttled quickly. I think OP might be better off with custom SMS integrations, lets say an RSS to SMS notification service for their fav news site that would send the article titles as individual sms messages and would allow requesting the 'full' article by means of an SMS reply

I know Twilio has a nice SDK for building solutions like that

posguy
Person to Person SMS is supposed to average below 1 message per minute. Different carriers will throttle your messages in different ways.
jansommer
Re: Twilio, just created an account a few days ago. Super simple API, and had receiving texts and robocalling myself with their content running within an hour or so. You don't have to store texts on your own, query Twilio's logs and they're all there.
justsomehnguy
> Theoretically you could create the world's worst VPN

Thanks for the laugh.

But your point is a valid, OP would have a better experience using even something like RFC 1149.

coldsauce
In 2014, I had a similar problem so I created Cosmos Browser, an Android based internet browser which allowed people to connect to the internet via SMS. It's pretty much dead now, but wouldn't take a lot of work to revive it if you really wanted to.

https://github.com/ColdSauce/CosmosBrowserAndroid

plants
This is incredible - I remember seeing this project at a hackathon back when I was in college and thinking it was so cool! So funny to see the actual author of it posting about it on HN now :). Really such a cool project - would love to see this become more mature.

Without actually looking through the code, I have a few questions:

1. How slow is it loading webpages? I think SMS would be a little sluggish since each message can only contain 160 characters.

2. How do you guys manage out of order text messages? Is there some sort of metadata that governs the order of a multi-part SMS?

Thanks so much for posting this - really a blast from the past.

coldsauce
Thanks! Yeah it was fairly slow but we did some work to try to make it faster.

Our process was

1. Remove all JS and CSS from the HTML file

2. Compress the file into a gzip stream

3. Base64 encode the file

4. Send it as a stream of text messages with some metadata on sequence numbers, etc

SMS uses the GSM 03.38 encoding which is a 7 bit encoding. I think we were working on building a custom encoding scheme for it rather than using Base64's 6-bit encoding, but never got around to it.

I think reddit.com (back in 2014 when it wasn't so fancy as it is now) took about 20 text messages to load, so you can imagine it would take less than a minute.

lukeasch21
This is crazy that I stumbled upon this post, I just learned about HackerNews today and saw this on the front page! I've been working on making a sort of revival project of Cosmos browser for a couple months now using a custom encoding and better compression. With the GSM 03.38 spec, I found there are 125 usable characters that I could use as a custom base, but I found out that for some reason the 0x10 column of the character set is mostly non-functional using any SMS API like Twilio. The characters from row 0x00 to 0x0A just show up as "?" instead besides the underscore. I contacted support for multiple API providers (Twilio and Plivo) and found that this is an issue on the operator level, which is quite surprising. I doubt this will ever be fixed because the problem runs so deep. This limits the usable characters to 115, which still has surprisingly good improvements in encoding efficiency compared to base64. I also used the (relatively) new Google brotli compression algorithm which allows me to compress even more efficiently. I'm still finishing a proof of concept so I don't have a GitHub repo up yet but I will soon (I'm a first-year CS student so I need to make my code somewhat presentable before it draws the internet's scrutiny, haha). Right now the server uses Python and the client app began as a fork of Cosmos browser. It turns out that getting code from the KitKat era to work on Android 11 isn't the best solution so I'm looking into rewriting the app. Regardless, thank you so much for your work! I'm super excited to finish the proof of concept and I hope to be able to implement the peer-to-peer system you briefly mentioned in the repo by having a "server" option you could turn on in the app that leverages a user's phone number and internet connectivity to allow other users to connect to that number.

Edit: I also want to add that I've looked into UCS-2 encoding (here: https://www.twilio.com/docs/glossary/what-is-ucs-2-character... ) but I'm not sure if the decrease in characters per message (only 70 instead of 160) is worth the greater amount of characters (theoretically 36,864 but probably includes many non-usable characters). It would also require a more complicated encoding algorithm, and I'm not sure how well supported this is by carriers internationally.

coldsauce
That's awesome - feel free to email me (should be on my website) if you want to talk more. Can share some tips and tricks or answer questions you might have.
mywittyname
This is a great, ambitious, but doable project for a first year CS student.

You should put up a github repo when you're done, regardless of how you feel about the way the code looks. It will absolutely help during a job search.

lukeasch21
I appreciate the comment - at first I wasn't sure if it was too ambitious, but once I realized that Android has libraries for parsing HTML and a documented way to send and receive texts, it was more manageable. It was also nice that ColdSauce had created something that I could use as a reference so I wasn't going in blind. I definitely plan on putting up a repo, probably within the next couple weeks. Going into this project I realized there's a lot more potential and the open source community would be beneficial to help expand the scope of this project!
tetsusaiga
Did this comment just remind you to update the readme? All 7 years old, and then 35 minutes ago, I love it lol. Very cool though
msoucy
"Oh man I knew someone in college who made a project EXACTLY for this purpose!" ... "Oh wow this project seems familiar..." ... "Oh wait that's the same person."
ethanwillis
You're basically talking about building a modem over SMS. I wouldn't use Twilio. The costs will be insane. Now what you could do, is get yourself a rooted phone stateside with custom software to receive requests for webpages via SMS. Then it sends back all of the data via SMS.
Someone
SMS is stateless, so you’d have to add sessions on top of it. The simplest probably would be to have a single endless session tied to your IMEI or phone number.

For UI, I would look half a century back. ed (maybe with slightly more verbose prompts. Sending a single character is as ‘fast’ and ’cheap’ as sending 100) may well be the editor of choice, for example.

Alternatively, look at speech interface systems, and adjust them for text input. Those typically are more constrained, though.

HWR_14
Most providers let you email phone numbers to send an SMS. I don't know if your LEO phone would. However, when I attempted it every "from" was a different random provider phone number (fewer digits than normal)

Keep in mind SMSs are pretty rate/bandwidth limited in your use case. SMSs originally (and probably still in your case) were based on having 140 bytes of freeish data in the keep-alive style pings between tower and phone. So you only get/send one SMs per (on regular devices I believe this is no longer the case).

Can you program the device you will be using, or does it need to be human readable?

One solution might be to run a cloud SMS service. You can set up an SMS endpoint on AWS with bidirectional communication. It would let you write as complex code as you would like to generate/parse the SMSs, and probably falls into almost free at a personal scale.

As a warning as someone who built a little SMS autosender (as I said earlier based on email), be careful you don't accidentally DoS yourself. Consider some way to turn it off. Constantly getting texts on a device without the ability to assign a specific ringtone because the event you was sure was rare happened more frequently was no fun until I changed the code.

moltke
I've never had the email/MMS gateways work. Personally I prefer JMP.chat which gives you a nice XMPP/MMS gateway and is much easier to work with.
HWR_14
Note that the OP must use SMS, not MMS.

In the US it wasn't an issue. What was the trouble? Keep in mind I was sending it to one or two people. I have no doubt it doesn't work on a mass scale.

moltke
JMP.chat does pure SMS by default, you have to ask to be part of the MMS beta.

I've only really tried AT&Ts gateways in the US from gmail, maybe something has changed but it never worked for me.

HWR_14
AT&Ts gateway worked for me around 2019. I was sending it from a domain that was set up with all the anti-spam things you have to set up to be a good sender (whatever rules so GMail etc don't dump all your messages right to spam, they are recorded but I don't recall them). It's possible that GMail was blacklisted because a lot of spammers had a ton of Gmail accounts.

Edit: Super important. You can turn that feature off per phone number. You (or your recipients) may have told att not to send them

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dashundchen
Not that this is a solution for you now, but about 10-15 years ago there were a whole slew of SMS services which were super useful for those without data.

Google 311 (EDIT: actually it was Google 411) let you conduct full searches, local listings, full text turn-by-turn navigation, weather, movie listings etc. You could also call a number and do an voice search that would text you back the results.

Twitter, AIM, Facebook all had SMS based interfaces as well. I remember a privately run system which served up transit schedules.

Was amazing to younger me to be on a bus and able to continue my AIM chats and check the bus schedule without a data plan. You could get useful services sent to your phone and not get sucked in endless feed scrolling.

whalesalad
Texting Google in the early 2000’s was so cool. Felt like magic at the time.
BoxOfRain
Seeing the web on a GPRS device was pretty cool too! It was a bit like watching an elephant perform ballet, seeing it happen at all made up for the fact it wasn't very good.
garciasn
The Hiptop / T-mobile Sidekick was a GPRS device which used a proxy to slim pages down to a manageable format for the device. I was using one in 2003 (the CSK) and it was quite the revolutionary piece of equipment for the time.

I still miss its ability to multitask, notify, and switch between apps while providing a full keyboard.

nvrspyx
I can't remember the name of it, but there was a service where you would text a question akin to a Google search and a real human would respond with the answer. If you signed up to be one of the responders (and proved your ability to find and return an accurate result quickly), they paid you like $0.01 per answer.

I thought it was a neat idea back when everyone was still using dumb phones.

sp332
ChaCha. It shut down in 2016.
arthurcolle
KGB (Knowledge Generation Bureau) was one, and then another one took its place
spookthesunset
Surely it was more than a penny a response. If each response took a minute then you’ll be making like $0.6 an hour. To make even $5 an hour you’d need to be sending a message every like 10 seconds.
a-dub
most (all?) cell service providers also had built-in email/sms gateways... so you could build your own services that did this just by building simple email interfaces.
jll29
We developed an SMS-based automatic question answering service deployed experimentally under the disposable brand name "myNuggets.net": https://www.prweb.com/pdfdownload/203601.pdf Venture capitalists/UK business angels did not share our vision that the Internet's future would be mobile in 2004/5 - well before the advent of the iPhone.

I had the idea for an all-automatic SMS info service when I jumped in a taxi in Edinburgh to attend a conference overseas and had left my hotel address on the kitchen table. I phoned a friend and said "Google that hotel for me, please" - and when I thanked him and hang up, I realized a human wasn't needed for many tasks like that, as they were well within the capabilities of Natural Language Processing (Information Extraction, Question Answering) even then.

We were proud that the prototype engineered had a 2 s round-trip time, including Web-meta search, answer extraction and SMS-HTTP gateway calls (very expensive back then).

wwweston
Uber as well. In fact, for the first year or so I used Uber, I never downloaded the app, just did SMS.
whateveracct
My grandfather used SMS to get weather & sports updates for years. He still isn't on the Internet and honestly would love to still use SMS.
gunfighthacksaw
> You could get useful services sent to your phone and not get sucked in endless feed scrolling.

Technology as it should be! Do you think the browser UI dominance was marketing, convenience, something more sinister…?

InsomniacL
SMS may be unlimited but are you sure it's not rate limited?
junon
This isn't a new concept. When I was at Uber I heard of some places in the world we did data over SMS, using it as a secure transport layer.
oregondan
This doesn't directly answer your question, but there's a nice SMS interface framework available for Django called RapidSMS[0]. It's been a few years since I've played with it, and never got around to testing "in the wild" / with a real phone, but, it makes the Request/Response <-> SMS gateway mapping pretty easy to navigate

[0] https://github.com/rapidsms/rapidsms