feat: Create MultiInputStream API primitive

[toubatbrian]

This class could solves the issue where user want the room to stay alive event after participant disconnected and being able to pipe the audio stream from new participants.

Related PR: #1018

Summary by CodeRabbit

• New Features

  • MultiInputStream primitive for managing multiple input streams dynamically.
  • Audio input now exposes a close operation to shut down underlying inputs.

• Bug Fixes / Reliability

  • Improved handling of audio recorder and subscribed track lifecycle for cleaner shutdown and interception behavior.

• Tests

  • Comprehensive tests covering MultiInputStream behavior, concurrency, edge cases, and error handling.

---

[changeset-bot]

🦋 Changeset detected

Latest commit: cc2fcf1

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 20 packages

Name	Type
@livekit/agents	Patch
@livekit/agents-plugin-anam	Patch
@livekit/agents-plugin-baseten	Patch
@livekit/agents-plugin-bey	Patch
@livekit/agents-plugin-cartesia	Patch
@livekit/agents-plugin-deepgram	Patch
@livekit/agents-plugin-elevenlabs	Patch
@livekit/agents-plugin-google	Patch
@livekit/agents-plugin-hedra	Patch
@livekit/agents-plugin-inworld	Patch
@livekit/agents-plugin-lemonslice	Patch
@livekit/agents-plugin-livekit	Patch
@livekit/agents-plugin-neuphonic	Patch
@livekit/agents-plugin-openai	Patch
@livekit/agents-plugin-resemble	Patch
@livekit/agents-plugin-rime	Patch
@livekit/agents-plugin-sarvam	Patch
@livekit/agents-plugin-silero	Patch
@livekit/agents-plugins-test	Patch
@livekit/agents-plugin-xai	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[coderabbitai]

📝 Walkthrough

Walkthrough

Adds a new MultiInputStream primitive that merges multiple ReadableStream inputs into a single output stream with dynamic add/remove and close semantics. Replaces previous DeferredReadableStream usage in AudioInput, RecorderIO, and ParticipantAudioInputStream to enable runtime input management.

Changes

Cohort / File(s)	Summary
Changeset & Export \.changeset/neat-parents-develop.md, agents/src/stream/index.ts	Adds a changeset entry and re-exports the new MultiInputStream from the stream module.
Core Implementation agents/src/stream/multi_input_stream.ts	New public MultiInputStream<T> class: manages concurrent pumps from multiple ReadableStream inputs, provides addInputStream/removeInputStream/close, tracks input count and closed state, and handles error/cleanup semantics.
Tests agents/src/stream/multi_input_stream.test.ts	Comprehensive tests validating creation, concurrent reads, dynamic add/remove, error handling, backpressure, teeing, close semantics, id uniqueness, and edge cases.
Audio Integration agents/src/voice/io.ts, agents/src/voice/recorder_io/recorder_io.ts, agents/src/voice/room_io/_input.ts	Replaces DeferredReadableStream with MultiInputStream<AudioFrame>, updates stream getters to return multiStream.stream, wires interception via addInputStream, adds AudioInput.close() and updates participant input lifecycle (currentInputId tracking and removal on close).

Sequence Diagram

sequenceDiagram
    participant Client
    participant AudioInput
    participant MultiInputStream
    participant InputStreams as Input<br/>Streams
    participant OutputStream

    Client->>AudioInput: create AudioInput
    AudioInput->>MultiInputStream: new MultiInputStream()

    rect rgba(100,150,200,0.5)
    Client->>AudioInput: attach input source
    AudioInput->>MultiInputStream: addInputStream(source)
    MultiInputStream-->>AudioInput: input ID
    end

    rect rgba(150,100,200,0.5)
    MultiInputStream->>InputStreams: read() (concurrent pumps)
    InputStreams-->>MultiInputStream: data chunk
    MultiInputStream->>OutputStream: write(chunk)
    end

    rect rgba(100,200,150,0.5)
    Client->>AudioInput: remove/swap input
    AudioInput->>MultiInputStream: removeInputStream(id)
    MultiInputStream->>MultiInputStream: cancel pump / release reader
    end

    rect rgba(200,150,100,0.5)
    Client->>AudioInput: close
    AudioInput->>MultiInputStream: close()
    MultiInputStream->>MultiInputStream: detach inputs / await pumps
    MultiInputStream->>OutputStream: close writer
    end

Loading

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

Possibly related PRs

• Add support for noiseCancellation frameProcessors #966: Touches the same voice I/O files (ParticipantAudioInputStream) and introduces overlapping lifecycle/stream management changes.

Suggested reviewers

• rektdeckard
• lukasIO
• 1egoman

Poem

🐰
Streams I tend and streams I sow,
Many inputs, one soft flow,
Add, remove—I'll let them play,
Pumps hum gently through the day,
Close with care, then hop away.

🚥 Pre-merge checks | ✅ 1 | ❌ 2

❌ Failed checks (1 warning, 1 inconclusive)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.
Description check	❓ Inconclusive	The PR description is vague and lacks structured information required by the template, making it difficult to fully assess the scope and quality of changes.	Fill out the complete PR template including explicit 'Changes Made', 'Pre-Review Checklist', 'Testing', and 'Additional Notes' sections with detailed information about modifications to AudioInput, RecorderIO, and ParticipantAudioInputStream.

✅ Passed checks (1 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'feat: Create MultiInputStream API primitive' directly and clearly summarizes the main change—introducing a new MultiInputStream class API.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch brian/allow-user-reconnect

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[toubatbrian]

@codex review

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.