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Launch HN: Vocode (YC W23) – Library for voice conversation with LLMs

379 points by KianHooshmand ↗ HN
Hey everyone! Kian and Ajay here from Vocode–an open source library for building LLM applications you can talk to. Vocode makes it easy to take any text-based LLM and make it voice-based. Our repo is at https://github.com/vocodedev/vocode-python and our docs are at https://docs.vocode.dev.

Building realtime voice apps with LLMs is powerful but hard. You have to orchestrate the speech recognition, LLM, and speech synthesis in real-time (all async)–while handling the complexity of conversation (like understanding when someone is finished speaking or handling interruptions).

Our library is easy to get up and running–you can set up a conversation in <15 lines of code. Check out our Gen Z GPT hotline demo: https://replit.com/@vocode/Gen-Z-Phone (try it out at +1-650-729-9536).

It all started with our PrankGPT project that we built for fun (quick demo at https://www.loom.com/share/0d0d68f1a62f409eb5ae24521293d2dc). We realized how powerful voice + LLMs are but that it was hard to build.

Once we got everything working, it was really cool and useful. Talking to LLMs is better than all the voice AI experiences we’ve had before. And, we imagined a host of cool applications that people can build on top of that.

So, we decided to build a developer tool to make it easy. Our library is open source and gives you everything you need in a single place.

We give you a bunch of integrations out-of-the-box to speech recognition/synthesis providers and let you swap them out easily. We have platform support across web and telephony (via Twilio), with mobile coming soon. We also provide abstractions for streaming conversation (this is good for realtime apps like phone calls) and for command-based/turn-based applications (like voice-based chess). And, we provide customizability around how the conversation is done—things like how to know when someone is finished speaking, changing emotion, sending filler audio if there are delays, etc.

In terms of “how do you make money” – we have a hosted version that we’re going to charge for (though right now you can get it for free! https://app.vocode.dev) and we're also going to build enterprise products in the future.

We’d love for you to try it out and give us some feedback! And, if you have any demos you'd like to see – let us know and we’ll take a crack at building them. We’re curious about your experiences using or building voice AI, what features or use cases you’d love to see, and any other ideas you have to share!

120 comments

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whitemary
Sounds great. FYI The site does not work well on Firefox iOS.
KianHooshmand
Ah! Have not tried this but will look into it – thank you :)

Our docs are hosted on Mintlify

endisneigh
it feels like every single company in the current YC batch has decided to pivot to LLMs
jjallen
It feels like LLMs can help me more and more each day with the stuff I want to build.
Kiro
I'm genuinely curious about this. I also get the feeling that many are pivots. ChatGPT hadn't even been released when the deadline for YC W23 was. Sure, GPT-3 was released earlier but it still feels like most companies are reactions to recent trends. If most are pivots, what did they pivot from?
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SkyPuncher
Generally, the hardest part of startups is the "fuzzy" product capabilities. LLM make it practical to codify much of what has previously been either (1) bruteforce/tedium (2) too labor intensive.

Like all startup waves, we'll see a bunch of them fail. However, I think we're going to see a lot of neat stuff come out of this as well.

joshspankit
To me that speaks of the possibilities for LLMs to solve a lot of big problems
sebzim4500
Kind of reminiscent of the dot com bubble. Most will fail, but the ones that survive could become the biggest companies in the world.

One obvious difference is that in this case the established players are making a serious attempt to develop the technology themselves. They do not intend to go the way of Blockbuster.

19h
Not sure if I understood that right -- is that something like Whisper + an LLM? Like [0]?

If OpenAI adds speech input to ChatGPT -- and considering the upcoming plugins -- isn't a possible enterprise specialisation of VoCode the only viable long term investment?

[0] https://twitter.com/ggerganov/status/1640022482307502085

KianHooshmand
Our belief is that at some point OpenAI will add a speech-to-speech model. This will improve the library functionality (since now the whole stack is controlled by a single entity, so the product will naturally be better latency/quality wise).

Our library is open source so that we can all build a development/utility layer on top of whatever foundational models are created. Plugins of course also improve what the agents can do. And right, we will be building enterprise focused products in the future!

ttul
OpenAI will absolutely add voice and my guess is that their voice support will rival anything on the market because they will train the voice model alongside the text and image models. This is likely months away if not weeks away.

Obviously just my $0.02:

I'd start building for the enterprise right now. Visualize a future where there are several multimodal AGIs that work with voice, images, and text. Be the enterprise voice layer for all of them. Build your moat there.

KianHooshmand
We totally agree – thank you for the feedback! :)
sebzim4500
I don't think there will be any demand for a self-hosted voice model with a SaaS LLM though. So that only works if they are going to train an LLM from scratch (or take the legal risk of using LLaMA).
KianHooshmand
And yes! It's STT/LLM/TTS where you can choose between different providers and run it across different platforms. It can be turn based (like the demo you linked from twitter) or streaming (this allows for conversation with interruptions!)
pbronez
Another big win here would be multi-lingual support.
jdiez17
Would be cool to support multi-language conversations. Just tried the Gen Z hotline and I got her to switch to Spanish (read back with a hilarious accent), but the voice recognition doesn't handle me speaking Spanish.
KianHooshmand
We haven't added the ability to switch languages mid conversation... but that's a very cool feature!

You can configure the initial language with the library though! So it works across several languages that are supported by the STT/TTS providers you choose

yodon
Thanks for going ahead and building this so the rest of us can focus on using it!
KianHooshmand
Of course! We loved working on this and chose to open source precisely for this reason. Heavily inspired by the work people are doing on Langchain and providing a usability/developer layer on top of foundational models.

Nothing like this existed for voice so we started cranking on it!

marcodiego
Can it be run fully locally?
KianHooshmand
yes! You can run the local version here in your bash https://docs.vocode.dev/python-quickstart#self-hosted
Vespasian
I think this used to mean can it be run offline and right now (usually) whenever there is an LLM involved the answer is soundly no
KianHooshmand
Ah! Right now our default is set to use OpenAI... but you can actually use local LLMs by creating a custom agent. We're going to add a full stack of local STT/TTS/LLM... just haven't had time for it yet!

If anyone wants to help with it we're totally open for contributions :)

moritonal
When I had time I was looking for an option to replace the Alexa in my house with an LLM+Whisper. When I have time I'll try to setup an extension to Home Assistant that's capable of interpreting voice and translating that into HA actions.
ajaynraj
Home Assistant is such a cool project :) great idea!
altryne1
Look at home assistant, it will come this year from them if anyone
joshspankit
I feel like GPT4 would be happy to help.

Though the winning version will likely be something like a local ChatGPT plugin (please let’s make this plugin style a standard that we can use for local AIs)

airstrike
EDIT: never mind, I must be dreaming
kritr
I can’t actually seem to find this with the search term “Vocode”.
wantsanagent
The phone number is a really fun demo! The pronunciation is off on a number of things: "LLM", dates ending w/ "AD", but the response delays are surprisingly short and the conversation is very natural. The 'bored and slightly annoyed' vocals make the generally helpful tone of the agent seem very sarcastic. Very funny and interesting!
ajaynraj
Thanks! It's a collab with rime.ai TTS. Unlike a lot of other TTS providers, they train on conversation, not podcasts/audiobooks so you get those disfluencies in speech that make it seem natural!
ljclifford
Lily from Rime here -- we were super happy to collaborate with Vocode on this amazing project. We haven't launched yet but keep an eye out later this week!
KianHooshmand
Lily is epic. Highly recommend checking out Rime when it's available!!
pncnmnp
Hey Lily, I really enjoyed reading Rime's blogs on Substack. For everyone, here's the link: https://substack.com/profile/131433903-rime-labs.

In fact, I had no clue about Cylinder Phonographs. Your discussion on Enrico Caruso motivated me to dig deeper. I found some cool gems:

1. History of the Cylinder Phonograph (https://www.loc.gov/collections/edison-company-motion-pictur...)

2. How the Cylinder Phonograph Works (https://www.youtube.com/watch?v=fWLlbk_bI7E)

Looking forward to watching the recording of your Bay Area NLP talk!

npilk
The Gen-Z GPT phone demo is really something. It's fascinating how differently I speak to this model compared to how I interact with more "formal" and text-first models.
ajaynraj
thank you!! The difference between a conversation with a command-based assistant and a conversational assistant backed by a LLM is subtly significant — you don't expect to have real conversations with the former and you actually engage with the latter.
altryne1
I called the GEN-Z phone like and it pretty much blew me away in response speed. It replied often faster than my family from the other side of the world would!
ajaynraj
thank you!! websockets have been around forever but they're still so fast.
tkgally
Me, too. I called it from Japan, and the delay before answers was no more than for regular international call with a human—maybe less.

The future seems to be arriving very quickly these days.

air7
This is really cool! I've been waiting for such a library to show up. Thank you. One thing: The documentation is currently a bit scarce as to how to tweak the assistant in terms of voice/prompt manipulation etc.

For example, it would be very instructional if you could show how you implemented the Gen-Z demo (great idea btw).

KianHooshmand
thank you for the kind words! absolutely agree – we're gonna beef up our tutorials and documentation... just have had so much to do but it's definitely one of our focuses now. stay tuned! :)
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davidxc
This is really amazing, thanks for building and sharing this!
KianHooshmand
thank you! love your feedback and please feel free to drop any questions in discord/on github
ilovepuppies
Congrats on the launch! Just got the demo React app up and running, very cool. I've wanted to interact with an LLM via real time speech for a while now, this will be perfect.

Important feedback on the live demo page: Make the default output sampling rate a normal talking speed. Right now it defaults to the highest rate if you don't set it / know which rate is best. First thing I did on the page was click the mic. The voice was too fast, and since the active mic disables the settings, I thought I couldn't change them so it might be broken. Also you want to make it clear that you can change the settings by turning off the mic. That took me a while to figure out.

Again, well done!

ajaynraj
thanks!! Sampling rate actually shouldn't affect talking speed - you can adjust the voice speed with this parameter[0] :)

[0] https://github.com/vocodedev/vocode-python/blob/main/vocode/...

ilovepuppies
To clarify, here's the demo URL I'm referring to: https://demo.vocode.dev/

You're right sampling rate doesn't change speed, whoops. But on that page you have to change / set the "Set Output Sampling Rate" to slow down the default voice speed.

ajaynraj
Ah, got it — that demo is a bit old and definitely has some bugs, my bad!
peteforde
I just called your voice demo, and immediately started sending the number to my friends. What an incredibly impressive and convincing demo. I'm going to update my standard mentoring wisdom: the only thing more compelling than a great product video is a phone number that you can call to have your first voice conversation with an AI.

If HN allowed memes - and thank goodness that it does not - there would be a room full of sombre gentlemen slow-clapping for you right here.

I hope that number survives the ineveitable deluge. How many callers can your system handle simultaneously?

KianHooshmand
Thank you!! Really glad you enjoyed it

We actually have no clue... but it seems to be holding up well. We can scale up the CPU as necessary but not sure about Twilio. I guess we will find out!

joshspankit
I’m getting “We’re sorry: an application error has occurred”. I’m guessing you’ve hit some scaling friction.
KianHooshmand
Yep we're definitely getting a large volume right now – working on it!
shostack
It will drop me with no notice but it was still a glimpse into the future once you get past the flashbacks to bad customer service automated support lines. If though the way it says "mems" instead of "memes" irked me for some reason.
MrBra
Where's the demo number? Can't seem to find it?
teabee89
The phone demo is incredible, but due to sound quality, I find it is speaking too fast and when it's telling me company names I literally had to ask to repeat or spell it out in NATO alphabet. Also not a fan of the "what'up?", would prefer something like "Yes, how may I help you?" just like an information hotline. Other than that it's quite impressive!
ajaynraj
thanks! we have a more "informational" phone number at +19105862633 that speaks a little slower (but sounds more robotic).
maroonblazer
I couldn't get through to the 'less robotic' # so tried this one. Really impressive, so I'm very curious to try the former.

Great work!

mdolon
This was one of the coolest demos I've seen in a while. You should share that number around more prominently (and get more bandwidth, starting to get errors!), it does a fantastic job of explaining what you do.
ajaynraj
thank you!! we also have another number which is prompted to act as a spokesperson for the product: (650) 835-7163
mkagenius
How is this achieving the real time response time? My chatGPT api calls are so slow.
all2
I asked GenZGPT "what's your name?" and she said something like "I'm a lim, but you can call me whatever you like." So I said "pick a name", and she said "how about you call me Zephyr, queen".

My immediate reaction was to figure out what to name this thing.

I also love that it can run locally. I need to get some hardware so I can have it run locally, and screen out spam calls. And maybe have it schedule appointments for me.

An AI butler needs a number of interface points:

- browser

- shell (cuz I might want it to SSH into a box and do stuff)

- email (browser could take care of this)

- phone

- text

And also IOT access, so she can call my cellphone and tell me when someone breaks in.

asdfzalsd
How were you able to get it running?

I tried to get it running my local and with the hosted web-app but it doesn't work :(

mind if I shoot you discord dm?

user-
It has some issues. It would only respond when I said "Hello??" after long silences, and would ignore anything else I said. Or maybe my voice sucks
jdcampolargo
Congrats. Do you have the repo for PrankGPT?
KianHooshmand
thank you! it's not live right now... but stay tuned for april 1 :)
chatgpt_bot
PrankGPT goes live on April fools day .. beautiful
wanderingmind
This looks awesome. My only nitpick is, I will suggest transcription integration with whisper.cpp[1], which in my simple CPU based tests (likely your most user base), works much much faster compared to OpenAI whisper

[1] https://github.com/ggerganov/whisper.cpp

KianHooshmand
We definitely want to do this! We've been talking about it (it's much better like you said for realtime); it's been hard to juggle everything we've wanted to add.. which is why we think this makes so much more sense open source!

We want the repo to be community built and a public good... would love contributors to start adding integrations we can't get to ourselves

ksarw
Congrats on the launch! One step closer to Jarvis.. ;)