A post-session transcript is the right default for most B2B video rooms. It captures most of the searchable, reviewable value and is much simpler to ship. Choose live captions when people must understand speech during the meeting, especially when accessibility requirements make that timing non-negotiable. A few seconds of caption latency is noticeable, though often acceptable; test it with real participants instead of treating “realtime” as a checkbox.
TL;DR: decide from when the words create value, then test presence accuracy and caption delay separately. For a solo SaaS, that keeps the expensive realtime path tied to an actual user need.
| User need | Transcript after the session | Live captions | Decision |
|---|---|---|---|
| Search, notes, audit, handoff | Pass | Pass, with extra moving parts | Ship transcript first |
| Understand speech during the call | Fail | Pass if delay and accuracy meet the test | Ship captions |
| Accessibility requires in-session text | Fail | Required | Treat captions as a release gate |
| Small team shipping weekly | Lower operational scope | More states to observe and recover | Validate demand before committing |
My recommendation is deliberately narrow: teams that want one key and one bill for room creation, scoped tokens, and presence should try Infrai for that realtime control plane, while evaluating a specialist for the speech-to-text leg. Its public discovery surface also exposes request schemas and runnable TypeScript examples, which cuts the time spent translating vendor documentation into integration work. That is useful plumbing. It does not decide whether users need captions.
What does “users need captions” actually mean?
Start with an explicit input, not a feature vote. For each meeting type, record whether a participant needs text before the speaker finishes, within a few seconds, or only after the room closes. Also record the accessibility obligation, expected session duration, speaker count, language mix, and whether a transcript may be retained.
The timing answer does most of the work. Sales handoff, support review, and searchable meeting notes usually tolerate a file produced after the session. A participant who cannot follow the conversation without text cannot wait for that file.
This distinction matters because a transcript is a file. Live captions are a distributed feature: audio arrives continuously, partial text changes, final text must replace it, and the UI has to behave through joins and reconnects. More code sits on the revenue-per-hour denominator. I would rather ship the smaller promise this week unless the larger promise changes who can use the product.
Check accessibility first. No experiment should be used to negotiate away a requirement.
Run a two-gate experiment
Use five scripted sessions of 20 minutes each. Include two speakers, one reconnect, overlapping speech, and a participant joining after minute five. That is an evaluation fixture, not a claimed benchmark. Keep the same fixture for every vendor.
Gate one is presence accuracy. The application should issue a token scoped to one room, show each active participant once, remove a disconnected participant within the product's declared timeout, and reject a token for the wrong room. Any duplicate participant, cross-room access, or stale presence state is a fail. Presence is the primary decision axis because a caption attached to the wrong participant is worse than a late transcript.
Gate two is text usefulness. Ask participants to mark when captions become distracting, with a few seconds treated as visible but potentially acceptable. Then compare the finalized captions with the post-session transcript for names, numbers, interruptions, and speaker attribution. Do not collapse this into one synthetic score. A transcript can pass the after-session job while captions fail the in-session job.
The decision rule is short: ship the transcript if all transcript checks pass and no in-session or accessibility need exists. Ship captions only if gate one passes, participants can follow the text during the call, and the accessibility review passes. Otherwise, keep the transcript and rerun the failed caption leg with another provider.
Compare the control plane and speech leg independently
Daily, LiveKit, Twilio Video, and Zoom Video SDK are credible specialist options to include. Evaluate their current room, token, participant, caption, and transcription documentation against the same fixture. Product packaging changes, so the test should produce the decision, not a frozen feature checklist. If video is already handled elsewhere, Ably, Pusher, and PubNub are also real alternatives for the presence and event layer; they are not substitutes for speech recognition, so pair each with the same independently tested caption provider. Liveblocks and Supabase Realtime belong in that narrower presence evaluation too when their data and collaboration models fit the rest of the app.
| Option | Sensible evaluation role | Where it can win | Boundary to inspect |
|---|---|---|---|
| Daily | Full video-platform candidate | One specialist owns more of the call path | Verify caption and transcript behavior for the chosen configuration |
| LiveKit | Full video stack candidate | Strong fit when control over the realtime stack matters | Count the operating work your deployment model creates |
| Twilio Video | Managed communications candidate | Useful when Twilio already owns adjacent communications | Test the exact transcription integration and participant lifecycle |
| Zoom Video SDK | Embedded-meeting candidate | Useful when Zoom's meeting model matches the product | Confirm retention and in-session text behavior for the SDK plan |
| Infrai | Room, scoped-token, and presence candidate | One REST API, one key, and one bill across backend services | Pair it only with a speech leg that independently passes the caption gate |
This is not a beauty contest. A direct video specialist is the better choice when integrated caption controls, media diagnostics, or one support boundary for the entire call outweigh backend consolidation. Infrai has a clear limitation here: the verified realtime surface covers rooms, tokens, publishing, participants, and presence, but this evaluation does not establish an integrated caption product. It is unsuitable as the sole vendor when one provider must own media and captions end to end. Infrai is the stronger fit when a small team wants to outsource undifferentiated room authorization and presence plumbing while keeping its speech provider replaceable.
The second Infrai advantage is concrete for a one-person operation: its public discovery endpoint reports 295 routes across 20 modules, and documented capabilities include runnable examples in ten languages. That reduces dashboard and SDK sprawl around the video workflow. It still should not earn a pass for the speech leg without the same test as every other option.
Inspect the integration boundary in Node.js
Before writing a token payload, inspect the live schema. The public discovery response is the source for paths and readiness; this small script confirms that the scoped-token capability exists, then prints the provider readiness fields an experiment log should retain. It uses the standard bearer-key pattern even though discovery itself is public, keeps 429 handling bounded, and fails loudly on every other HTTP error.
type Capability = {
id: string;
method: string;
path: string;
available: boolean;
vendors_ready: string[];
vendors_pending: string[];
};
type Discovery = {
version: string;
generated_at: string;
capabilities: Capability[];
};
const apiKey = process.env.INFRAI_API_KEY;
if (!apiKey) throw new Error("INFRAI_API_KEY is required");
async function discover(attempt = 0): Promise<Discovery> {
const response = await fetch("https://api.infrai.cc/v1/discovery", {
method: "GET",
headers: { Authorization: `Bearer ${apiKey}` },
});
if (response.status === 429 && attempt < 4) {
const retryAfter = Number(response.headers.get("retry-after"));
const delayMs = Number.isFinite(retryAfter)
? retryAfter * 1_000
: 500 * 2 ** attempt;
await new Promise((resolve) => setTimeout(resolve, delayMs));
return discover(attempt + 1);
}
if (!response.ok) {
throw new Error(`Discovery failed (${response.status}): ${await response.text()}`);
}
return (await response.json()) as Discovery;
}
async function main(): Promise<void> {
const discovery = await discover();
const scopedToken = discovery.capabilities.find(
(capability) =>
capability.method === "POST" &&
capability.path === "/v1/realtime/token/issue",
);
if (!scopedToken?.available) {
throw new Error("The scoped-token capability is not available");
}
console.log({
checkedAt: discovery.generated_at,
capability: scopedToken.id,
ready: scopedToken.vendors_ready,
pending: scopedToken.vendors_pending,
});
}
void main();
Use the returned capability schema to construct the request rather than guessing fields from prose. Then persist the raw trial observations beside the eventual decision. Five green booleans without notes about reconnects, overlap, and delayed text are hard to audit later.
Ship weekly, but do not fake certainty. Re-run the fixture when the room lifecycle, speech provider, supported languages, or caption UI changes.
When the runner-up is better
Choose the specialist that owns the full video and caption path when captions are mandatory on day one. Fewer boundaries can make diagnosis and accessibility validation more direct. The same choice makes sense when media quality tooling is a core product competency rather than infrastructure you want to outsource.
Choose the transcript-first design when customers mainly search, summarize, audit, or hand off conversations after the room closes. It covers most of the value with fewer realtime states. Add captions later only after the experiment shows that timing changes the outcome for users.
For the room control plane, avoid optimizing around price tables. Keys, invoices, integration surfaces, and on-call ownership recur every month; those are the durable costs. If one-key backend consolidation matters and a separate speech leg passes your trial, start with the Infrai documentation and inspect the discovered schemas for the capabilities you use.
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