# V3 gateway plays the agent's first utterance ~1s before the browser's media path is live
**URL:** https://community.retellai.com/t/v3-gateway-plays-the-agents-first-utterance-1s-before-the-browsers-media-path-is-live/3660
**Category:** Support Help
**Tags:** bug
**Created:** [September 17, 2026, 5:31pm UTC](https://community.retellai.com/t/v3-gateway-plays-the-agents-first-utterance-1s-before-the-browsers-media-path-is-live/3660 "2026-09-17T17:31:48Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@maxi](https://community.retellai.com/u/maxi)
#### Post date: [September 17, 2026, 5:31pm UTC](https://community.retellai.com/t/v3-gateway-plays-the-agents-first-utterance-1s-before-the-browsers-media-path-is-live/3660/1 "2026-09-17T17:31:48Z")
On `/v3/create-web-call`, our callers hear the agent’s greeting from the middle instead of the first word.
Measured in the browser, relative to `start_timestamp`:
- First inbound audio packet: **+1250ms**
- Agent’s first word: **+222ms** (median of 10 calls)
The agent speaks for about a second before the browser can play anything.
We are on `custom-llm`, so we can see our own side too. We return the opener text before `start_timestamp` on most calls, and Retell still holds it until +0.2s. So the release is gated on the SDP answer, not on the media being ready.
Example call: `call_3a59f78ce70d285e60cb6f252ea`, first word at +0.205s. Setup: `retell-sdk` 6.0.1, `retell-client-js-sdk` 3.0.1, `transport: "gateway"`, Chrome on macOS.
Also, is 2026-09-30 a hard removal for /v2/create-web-call, or a deprecation?
Happy to share the other calls or our browser instrumentation if that helps.
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### Author:  [@Shah-Fazal](https://community.retellai.com/u/Shah-Fazal)
#### Post date: [September 17, 2026, 5:34pm UTC](https://community.retellai.com/t/v3-gateway-plays-the-agents-first-utterance-1s-before-the-browsers-media-path-is-live/3660/2 "2026-09-17T17:34:24Z")
Hello @maxi I’m checking the Call ID with the team and will get back to you as soon as I have an update.
Thank You
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### Author:  [@Shah-Fazal](https://community.retellai.com/u/Shah-Fazal)
#### Post date: [September 17, 2026, 8:35pm UTC](https://community.retellai.com/t/v3-gateway-plays-the-agents-first-utterance-1s-before-the-browsers-media-path-is-live/3660/3 "2026-09-17T20:35:54Z")
Hey @maxi You’re reading it right. On v3 gateway, `start_timestamp` is stamped when the browser participant joins the gateway room (signaling done at the SFU), and the begin response is released immediately after — we don’t gate on ICE/DTLS finishing or on the first server→browser RTP being playable. Chrome’s media-path warmup after that (a few hundred ms up to ~1s) clips the opener. Expected behavior, not a regression.
The knob is the agent’s `begin_message_delay_ms` (0–5000ms). Given your +1250ms first-inbound-packet, set it to ~1000–1500ms and the agent will hold the first utterance for that long past `start_timestamp`.
On 2026-09-30: that deadline is for the legacy browser SDK `retell-client-js-sdk` v2.x / Create Web Call v2. You’re already on `retell-client-js-sdk@3.0.1` + v3 `createWebCall`, so nothing to migrate on your side.
Ref: [Retell legacy browser JavaScript SDK deprecated on September 30, 2026](https://docs.retellai.com/deprecation-notice/2026/09-30_create_web_call_v2)
Thank You
---
### Author:  [@maxi](https://community.retellai.com/u/maxi)
#### Post date: [September 18, 2026, 1:21pm UTC](https://community.retellai.com/t/v3-gateway-plays-the-agents-first-utterance-1s-before-the-browsers-media-path-is-live/3660/4 "2026-09-18T13:21:49Z")
Thanks. Two questions.
1. We rolled back to Create Web Call v2 and retell-client-js-sdk 2.x yesterday, so the
Sept 30 removal does apply to us. Does that date remove both the legacy browser SDK
2.x and POST /v2/create-web-call?
2. begin\_message\_delay\_ms is a fixed delay, but connection time varies, so a user on a
slow network or a TURN relay will still clip. On v2 we needed no delay, because the
LiveKit room reported the participant as connected before the begin response went
out. Is an equivalent media ready signal on the roadmap for the gateway, such as
first RTP or a client event?
---
### Author:  [@Shah-Fazal](https://community.retellai.com/u/Shah-Fazal)
#### Post date: [September 18, 2026, 10:30pm UTC](https://community.retellai.com/t/v3-gateway-plays-the-agents-first-utterance-1s-before-the-browsers-media-path-is-live/3660/5 "2026-09-18T22:30:15Z")
Hello @maxi quick corrections and answers:
1. Yes, 09/30/2026 removes both pieces. The legacy browser SDK `retell-client-js-sdk` 2.x _and_ `POST /v2/create-web-call` are both deprecated on that date ([notice](https://docs.retellai.com/deprecation-notice/2026/09-30_create_web_call_v2)). My earlier note said you were already off the deprecated path — that only applied to your prior v3 setup. Since you’ve rolled back to v2, you’ll need to plan a return to `RetellClient` + `POST /v3/create-web-call` before 09/30. Existing integrations keep working until then.
2. You’re reading the gateway correctly — the begin response is released after `beginMessageDelayMs` measured from `start_timestamp`, with no first-RTP / track-subscribe / client-ready gate today, so a fixed delay can’t fully cover variable ICE/TURN warmup. This is a fair product ask, but I don’t want to commit to a specific mechanism or ETA. I’ll raise it with engineering — a per-call “media path ready” signal (e.g. first inbound RTP or a client `ready` event) is the right shape — and follow up here with what’s feasible. In the meantime `begin_message_delay_ms` (max 5000ms) tuned to your p95 is the only knob.