Amazon Chime SDK preview
Every room TEEI runs on Chime TEEI holds its live sessions in 25 room formats on Amazon Chime, across 5 programmes. Open any of them as demo personas, then watch the join, the media and the events from a panel beside the room.
Control region eu-west-2, London. Media in eu-west-1, Ireland. Computed from the code when this page loads.
Start here
A booked 1:1 with captions
The whole path in one room: the join, the media, captions, the Chime events and the row the company report reads.
Open the 1:1
Join as both people. One window for each demo persona, side by side.Turn on captions in both. Transcription starts only when both agree, and the panel shows the StartMeetingTranscription call.Leave, then press Settle now. The Chime events arrive, and the settled row appears the way the company report reads it.In the panel Join · Media · Captions · Events · Settle
Room formats 25 in 5 programmes
Room configurations 9 formats that behave the same, merged
Room components 2 VideoRoom for 1:1, GroupVideoRoom for the rest
Two more to start with Each opens a real Chime meeting in the London test account with demo personas signed in. A panel beside the room shows what happens underneath.
Skills Academy · GroupVideoRoom
A webinar where the host invites someone up Open the host and a participant. When the host invites the participant to speak, the panel shows the UpdateAttendeeCapabilities call and Chime's answer.
In the panel Join · Capabilities · Events
Open the webinar
TEEI Language · GroupVideoRoom
Make an event fail, then replay it Arm the fault path and the next Chime event is refused three times. Watch it land in the dead letter queue, drain it, and see it stored.
In the panel Fault path · Events
Open the group room
All 25 rooms Grouped by what Chime and the room do: who may speak, captions, host tools and video tiles. Formats that agree on all of it share a card.
Each room gets its own demo personas. A persona already in another room is never waited for: the preview signs in a fresh instance of it, same name, same portrait, its own demo account. Pressing a row again while its room has 10 minutes or more left opens the same room.
VideoRoom · 3 formats
One-to-one call Everyone speaks Captions when both agree No host tools 25 video tiles, Chime's limit Booked 1:1 session conversation
TEEI Language · learner, volunteer
Open with demo personas
Call from the chat conversation
TEEI Language · learner, volunteer
Open with demo personas
Booked 1:1 session conversation
TEEI Mentorship · learner, volunteer
Open with demo personas
CallGuestRoom on GroupVideoRoom · 1 format
A guest joins a 1:1 call Everyone speaks No captions Host tools: the volunteer 25 video tiles, Chime's limit Guest in a 1:1 call conversation
TEEI Language · volunteer, learner, guest
Open with demo personas
GroupVideoRoom · 7 formats
Group with a host, everyone speaks Everyone speaks No captions Host tools: the host 25 video tiles, TEEI's cap Speaking Café conversation
TEEI Language · volunteer, learner
Open with demo personas
Discussion Group conversation
TEEI Language · volunteer, learner
Open with demo personas
Workshop conversation
TEEI Language · volunteer, learner
Open with demo personas
Study Group conversation
TEEI Language · volunteer, learner
Open with demo personas
Group mentoring conversation
TEEI Mentorship · volunteer, learner
Open with demo personas
GroupVideoRoom · 4 formats
Group without a host Everyone speaks No captions No host tools 25 video tiles, TEEI's cap Social Club conversation
TEEI Language · learner, volunteer
Open with demo personas
Learner café conversation
TEEI Language · learner
Open with demo personas
Peer-led Language Café conversation
TEEI Language · learner
Open with demo personas
Peer practice conversation
TEEI Language · learner
Open with demo personas
GroupVideoRoom · 2 formats
The host presents, the audience listens The host speaks, the room mutes the audience No captions Host tools: the host 25 video tiles, TEEI's cap Workshop presentation
TEEI Language · volunteer, learner
Open with demo personas
GroupVideoRoom · 4 formats
A session with a moderation team Everyone speaks No captions Host tools: host, co-host and moderator 25 video tiles, TEEI's cap Workshop conversation
Skills Academy · host, co-host, moderator, speaker, participant
Open with demo personas
Clinic conversation
Skills Academy · host, co-host, moderator, speaker, participant
Open with demo personas
Expert Q&A conversation
Skills Academy · host, co-host, moderator, speaker, participant
Open with demo personas
Class conversation
Skills Academy · host, co-host, moderator, speaker, participant
Open with demo personas
GroupVideoRoom · 2 formats
A stage: speakers are invited up Speakers are invited up, enforced by Chime capabilities No captions Host tools: host, co-host and moderator 25 video tiles, TEEI's cap Expert Q&A presentation
Skills Academy · host, co-host, moderator, speaker, participant
Open with demo personas
Webinar presentation
Skills Academy · host, co-host, moderator, speaker, participant
Open with demo personas
MeetingRoom on GroupVideoRoom · 1 format
TEEI Meeting Everyone speaks No captions Host tools: the host 25 video tiles, TEEI's cap Meeting conversation
TEEI Meetings · host, guest
Open with demo personas
MeetingRoom on GroupVideoRoom · 1 format
TEEI Meetings webinar Speakers are invited up, enforced by Chime capabilities No captions Host tools: the host 25 video tiles, TEEI's cap Webinar presentation
TEEI Meetings · host, speaker, listener
Open with demo personas
What TEEI changes in the Chime SDK Every room above runs with these. Compared with a bare MeetingSessionConfiguration from amazon-chime-sdk-js 3.32.0, measured when this page loads.
Setting SDK default TEEI Set in Video in the browser enableSVC false true app/ lib/ lc/ chime-session-tuning.ts :124videoDownlinkBandwidthPolicy none (the SDK picks at session start) Video Priority Based Policy, delay factors (0, 1), server-side adaption Bandwidth Probing And Remote Video Quality Adaptionapp/ lib/ lc/ chime-session-tuning.ts :125videoUplinkBandwidthPolicy none (the SDK picks at session start) Serial Chime Video Uplink Policyapp/ lib/ lc/ chime-session-tuning.ts :126Connection and reconnect in the browser connectionTimeoutMs 15000 30000 app/ lib/ lc/ chime-session-tuning.ts :41reconnectTimeoutMs 120000 300000 app/ lib/ lc/ chime-session-tuning.ts :50reconnectLongBackOffMs 5000 8000 app/ lib/ lc/ chime-session-tuning.ts :57connectionHealthPolicyConfiguration . connectionUnhealthyThreshold 25 40 app/ lib/ lc/ chime-session-tuning.ts :68connectionHealthPolicyConfiguration . connectionWaitTimeMs 10000 20000 app/ lib/ lc/ chime-session-tuning.ts :68connectionHealthPolicyConfiguration . missedPongsUpperThreshold 4 6 app/ lib/ lc/ chime-session-tuning.ts :68Media in the browser keepLastFrameWhenPaused false true app/ lib/ lc/ chime-session-tuning.ts :139attendeePresenceTimeoutMs 0 Left at the default on purpose app/ lib/ lc/ chime-session-tuning.ts :141audioVideo . setAudioProfile SDK default bitrate, mono, redundancy on 40 kbit/s, mono, redundancy on app/ lib/ lc/ chime-session-tuning.ts :169Set on the service side in the meeting Lambda and the room CreateMeeting MeetingFeatures . Audio . EchoReduction UNAVAILABLE AVAILABLE lambda/ lc-video-session/ index.ts :867VoiceFocusDeviceTransformer spec default model ns_es (noise and echo) when the meeting offers echo reduction, else the default app/ components/ VideoRoom.tsx :2816StartMeetingTranscription EngineTranscribeSettings one fixed language, no stabilisation Identify Language, Preferred Language en-US, partial results stabilised (high)lambda/ lc-video-session/ index.ts :656
What happens under a room The panel beside the room times each of these steps for the meeting you opened.
When someone presses Join The Worker reports steps one to five as they happen. The browser sees step six.
Who may enter The Worker checks the booking and the role Meeting lease The Worker reuses or reserves the meeting Signed token The Worker signs a short-lived token API Gateway The authorizer checks the token, in London Meeting Lambda CreateMeeting and CreateAttendee in eu-west-2 Media flowing The browser reaches Chime media in eu-west-1 After the room The same path production uses, in the London test account.
Chime events attendee joined, left, dropped, screen share on and off, meeting ended EventBridge rule those six types, preview meetings only Forwarder retries for up to 6 hours, then a dead letter queue Ingest and receipt the Worker stores the event, a second rule keeps an S3 receipt Settlement every 15 minutes, or Settle now here What this preview cannot show
Production counts The figures in the article count real sessions in production. The preview only has its own.
The nightly company sync The company report reads real companies and employees. The preview shows the row the way the report reads it, with the same rule.
Production alarms and the canary They watch the production resources. The preview has its own dead letter queue and drain, with no alarm that pages anyone.
Real networks in Ukraine They can only be emulated, and Chrome's network throttling does not slow WebRTC media.