v0.18.0 — sound banks from portal-curated playlists

[this-fifo]

createSoundBank can now take a playlist_id instead of seeds. Slots curated in the portal become pools, so the sounds a game plays can change without shipping code.

local bank = AudioScape:createSoundBank({ playlist_id = "sfx-1785256484251" })
bank:resolveAsync()

sound.SoundId = "rbxassetid://" .. bank:pick("footstep")

The design call

Slots are used exactly as curated — no similarity expansion at runtime. Whoever built the bank already decided what belongs in each slot, and quietly adding sounds they never listened to is the same mistake as swapping a game's gunshot unasked. Widening a slot is a decision made in the portal, where it can be heard first. bank.Pools[name].source reads "playlist" on this path.

Everything downstream is unchanged: pick still avoids immediate repeats, and reportUnavailable still drops a sound that fails to load.

Types

getPlaylist now understands playlists carrying sound effects — playlist.kind (music / sfx / mixed), playlist.slots, and a sounds list beside tracks. Kept separate rather than unioned into tracks so neither list needs a type test before use, which strict-mode Luau makes genuinely painful.

Sounds carry the same shape as sfxSearch results including sound_start_sec / sound_end_sec — trimming to sound_start_sec removes the leading silence that makes an impact feel late.

seeds is now optional. Pass seeds or playlist_id, not both.

Verification

• 3 new unit blocks in soundBank.spec.luau — playlist pools, picking, and the failure paths (a 404 playlist, a music playlist with no slots, both rejected rather than resolving to an empty bank that picks nil at runtime). 21 specs pass.
• 2 new Open Cloud steps — getPlaylist (sfx) asserts slots account for every sound; createSoundBank (from playlist) asserts the resolved pools match the declared slots index for index. 27/27 green against the live API through a real Roblox engine.
• stylua, selene, and luau-lsp analyze clean.

The server side is already deployed, so the smoke ran against the real endpoint rather than a staging shim.