[Platform][Agent] Introduce Speech support

[Guikingone]

Q	A
Bug fix?	no
New feature?	yes
Docs?	yes
Issues	--
License	MIT

• Introduce support for TTS, STT and STS for agents
• Add new configuration options to configure "speech" at agent-level.

Example for an OpenAI-based STS agent:

ai:
    platform:
        elevenlabs:
            api_key: '%env(ELEVEN_LABS_API_KEY)%'
        openai:
            api_key: '%env(OPENAI_API_KEY)%'

    agent:
        sts_openai:
            platform: ai.platform.openai
            model: gpt-4o
            speech:
                enabled: true
                platform: ai.platform.elevenlabs
                tts_model: eleven_multilingual_v2
                tts_options:
                    voice_id: some-voice-id
                stt_model: scribe_v1

• Agents can either be TTS or STT independently
• A SpeechConfiguration object handle the speech configuration
• A SpeechProcessor handle the input/output

[OskarStark]

To me we maybe should introduce capabilities also to platforms rather than having a voice component. As far as I understand I cannot use the Voice component standalone, right?

I don't think a dedicated component is the way to go here

[Guikingone]

We can introduce it via the Platform, could be easier, the voice can be used without agents but it will requires the Platform at least.

Will update the PR to match this approach 👍🏻

[OskarStark]

I agree, Agent scope is not needed 👍🏻

[chr-hertel]

Hi @Guikingone, i agree that week lack some kind of guidance on how voices work - but same goes for other binary stuff like creating images or videos.

so two things i would like to understand

• what's the high-level goal here - like what do you want to build?
• why is it an extra component and not part of Platform?

btw, "speech" is more common than "vioce" isn't it?
btw2, have you seen the demo around audio and video?

[Guikingone]

what's the high-level goal here - like what do you want to build?

The main goal is to add the capacity to have an agent/platform that can "listen" and answer to inputs thanks to voice / speech (voice is used as a sugar here, could be renamed to speech), creating a workflow where you can submit voice, call the platform that transforms it to speech / text (depending on the situation you're in) and returning it to the user without frictions.

why is it an extra component and not part of Platform?

It is now part of Platform, I just pushed an update on it following the comment from @OskarStark.

btw, "speech" is more common than "voice" isn't it?

Agreed, could be renamed to Speech.

btw2, have you seen the demo around audio and video?

Yes, the goal is to ease it with a "built-in" approach / API that stays transparent for the user.

[chr-hertel]

just realized we should the "audio" demo to "speech" as well - and i'm def not really happy with that solution there.

can we make it as easy as the structured output - like with an listener?

i like that starting point:

$result = $platform->invoke('eleven_multilingual_v2', new Text('Hello world'), [
    'voice' => 'Dslrhjl3ZpzrctukrQSN', // Brad (https://elevenlabs.io/app/voice-library?voiceId=Dslrhjl3ZpzrctukrQSN)
]);

echo $result->asVoice();

what would be the return type here? would it be same as asBinary() or asDataUri()

[Guikingone]

can we make it as easy as the structured output - like with an listener?

Could be something to explore, the API is not locked for now.

what would be the return type here? would it be same as asBinary() or asDataUri()

My first approach was to do the same thing as asBinary to ease the usage.

[Guikingone]

Well, might seems weird but here we go, stt, tts and sts are working like a charm ... 👀

[OskarStark]

@chr-hertel will have a look soon, not sure it will land in 0.3, lets keep it for now

[Guikingone]

Hi @OskarStark @chr-hertel, yes, I know, again 😄

I think that this time, that's the one, while thinking about #1572 and the comment from chris, I thought about this PR and the listener approach didn't looked like "THE" solution, especially while we have the processors, so, I asked Claude (yes, sometimes, asking for an external opinion might lead to a solution) for a "reworked implementation" that could ease the user experience and the maintenance of it, it submitted a solution close to the processors and I did the final tweaking.

So, what changed?

Now, the speech configuration is moved where it needs to be, at the Agent level, each agent can specify which platform to use, the options and so on, no more "in or out option", the agent handle the configuration, simple, clever, straight to the point.

The Platform still an important aspect of the PR (as the configuration is in the Platform but shared with the Agent), I also simplified the DI experience along with the code in the SpeechProcessor (the main entry point for speech now).

I updated the examples and reworked the documentation, much better, make more sense IMHO to be like that.

I let you take a look at it and review it if you think it deserves to be reviewed, is #1572 needed anymore? Thought question, if this PR is merged, probably not, at least, I don't see use case except for the validation/evaluation part (for now) that could require it (as speech is now at the agent level), probably another topic for another day 😄