How to enable Live Streaming over Direct Line for a Copilot Studio–deployed agent?

[seulki-kt]

I have a question

I’m connecting a Copilot Studio–deployed agent to Web Chat via Direct Line (same environment as the sample below).
The docs suggest implementing live streaming on the bot side, but in my case the app is built with Copilot Studio, not a custom Bot Framework bot.

Question:

Is there a way to enable live streaming (token-by-token / incremental responses) when using a Copilot Studio agent over Direct Line?

If yes, what settings or configuration are required (e.g., feature flags in Copilot Studio, Direct Line/Web Chat options, or server-side capability toggles)?

Currently, using the sample setup, responses are not streamed; they appear only after completion.

Sample I’m following:
👉 https://github.com/microsoft/Agents/tree/main/samples/nodejs/copilotstudio-webchat-react

✅ Expected Behavior

Responses from the agent should stream progressively (e.g., partial tokens/segments) in Web Chat when connected through Direct Line.

🧱 Actual Behavior

Responses render only after the entire message is generated—no incremental streaming observed.

🔁 Steps to Reproduce

Deploy an agent using Copilot Studio.

Connect the agent to a React Web Chat app via Direct Line using the sample linked above.

Send a prompt that usually takes a few seconds to answer.

Observe that the message renders only when complete (no streaming effect).

🖥️ Environment

Copilot Studio Agent: built in Copilot Studio (no custom Bot Framework code)

Connection: Direct Line → Web Chat (React)

Sample: copilotstudio-webchat-react

Packages:

{
"@azure/msal-browser": "^4.13.1",
"@microsoft/agents-copilotstudio-client": "^1.0.15",
"botframework-webchat": "4.18.1-main.20250912.cbaf98f",
"botframework-webchat-fluent-theme": "4.18.1-main.20250912.cbaf98f",
"react": "16.8.6",
"react-dom": "16.8.6"
}

Browser: Chrome (latest)

Region/Tenant: (add if relevant)

❓Questions / Clarifications

Does Copilot Studio support server-driven streaming when used with Direct Line (not Direct Line Speech)?

If supported, how do we enable it? Any required Copilot Studio settings, Direct Line flags, or Web Chat props to turn on streaming?

If not supported today, is there a recommended workaround (e.g., custom bot handoff, different channel, or preview feature) or any ETA?