# PLATFORMS — per-platform join packs & doctor output

Join packs are the browser driver's per-platform adapters. Each pack is a
versioned file (TOML) pinning the selectors and flow for one platform at a
stated browser/client build. Selector drift is the primary maintenance
cost; packs are pinned so drift is a loud failure, not a silent one.

## Pack format (browser driver, post-MVP)

```toml
[meta]
platform = "jitsi"
pack_version = 3
tested_client = "meet.jit.si 2026-06"
url_pattern = '^https://[^/]+/#?[a-zA-Z0-9-]+$'

[join]
# Ordered actions: goto → name-entry → premit-wait → admit → device-grant
steps = ["goto", "grant_permissions", "enter_name", "join"]
selectors = { enter_name = "#premeeting-name-input", join = "[data-testid='join-button']" }

[devices]
camera_selector = "video"
mic_selector = "audio"
```

Doctor output — `freestream probe --platform <p>` prints, per platform:
pack availability + version, browser build found, virtual camera present,
virtual mic present, and a join dry-run result.

## Platform status (v0.1.0)

| Platform | Path | Status |
|---|---|---|
| LiveKit (incl. self-hosted Jitsi-via-LiveKit) | `livekit` driver, native WebRTC | **MVP target** — no selectors, no ToS gray zone |
| Jitsi (meet.jit.si) | browser pack or LiveKit backend | MVP target via LiveKit driver |
| Google Meet | browser pack | Blocked until pack + virtual-camera validation; ToS gray zone (see CONSENT.md) |
| Zoom | browser pack | Same |
| Teams | browser pack | Not planned in MVP |
| SIP audio | `sip` driver | Post-MVP |

## Ship order (from the concept's next-steps)

1. **Jitsi/LiveKit first** — open stack, native driver, zero selector drift.
2. Virtual-camera injection on modern macOS browser clients (Chrome +
   BlackHole) — validated per-pack before any Meet/Zoom pack ships.
3. Meet/Zoom packs last, gated on a ToS review, with the browser pack
   version pinned to a tested client build.

## Virtual camera / mic

- **Linux:** v4l2loopback kernel module + PulseAudio/PipeWire null sink.
  `freestream doctor` checks module presence (`/dev/v4l2byid` scan) and
  sink creation rights.
- **macOS:** OBS Virtual Camera or a CoreMediaIO DAL plugin for video;
  BlackHole for loopback audio. Screencapture-kit permission required.
- **Windows:** post-MVP; OBS Virtual Camera is the reference backend.