[yuyixg]

Follow-up to #1467, addressing its two review findings.

The problems

1. The mark kept more than the caller heard. Text goes out to Twilio faster than it is spoken, so when the caller cut in, what had been sent could run well past what was played. The history then took the sent part as heard, and a question the caller never heard was still treated as asked: the very thing feat(twilio): keep a reply the caller cut off as the part they heard #1467 set out to stop.
2. A timed-out reply could be marked as cut in on. After a turn times out, FailAsync drops the stream and plays the apology, but _isProcessing and _streamedThisTurn stay set. A caller talking over the apology set _cutInMidReply, and the orphaned turn's reply was stored as one the caller interrupted.

What this does

• The interrupt handler reads utteranceUntilInterrupt, where Twilio says playback stopped. MarkWhatTheCallerCutOff cuts there when it is the start of what went out, and where the sending stopped otherwise (field missing, or the cut-in landed on something else, such as a filler); that fallback is logged.
• An interrupt once the stream was already dropped, or after the session ended, no longer marks the turn.

A side effect of (1): a reply fully sent but not yet stored when the caller cuts in used to be left unmarked (nothing unsent), and is now marked where playback stopped.

Note

Twilio's docs show utteranceUntilInterrupt only in an example (a partial sentence), without a formal definition. The cut relies on it being the part played before the interruption; if it is not, the fallback keeps today's behaviour.

Testing

Covered downstream, where the relay session runs against a fake WebSocket:

• a cut-in with utteranceUntilInterrupt matching the sent text stores only the heard part plus the mark;
• one that does not match falls back to the sent text;
• a caller talking over the timeout apology leaves the orphaned reply unmarked.

The first and third fail on current master and pass with this change. There is no test project here that covers the Twilio plugin.

🤖 Generated with Claude Code

[qodo-code-review]

Code Review by Qodo

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PR Summary by Qodo

Mark Twilio replies at the playback cutoff, not after a timeout

🐞 Bug fix 🕐 10-20 Minutes

AI Description

• Use Twilio’s playback cutoff to keep unheard reply text out of conversation history.

Diagram

graph TD
  T["Twilio interrupt"] --> G{"Active stream?"} -->|yes| P{"Heard prefix?"} -->|yes| H["Heard cutoff"] --> R["History rewrite"]
  P -->|no| F["Sent cutoff"] --> R
  G -->|no| N["No cut mark"]

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High-Level Assessment

Use Twilio’s reported cutoff with prefix validation and the existing sent-text fallback. Sent text alone cannot establish what was played, while the guard prevents timeout-apology interruptions from marking an orphaned reply.

Files changed (1) +25 / -5

Bug fix (1) +25 / -5

ConversationRelaySession.csTrack the heard cutoff and exclude dropped turns from cut-in marking +25/-5

Track the heard cutoff and exclude dropped turns from cut-in marking

• Captures and resets Twilio’s utteranceUntilInterrupt for each turn, then uses it to mark unheard reply text when it prefixes the streamed text. Falls back to the sent-text position when it does not match or is absent, and ignores interrupts after the stream was dropped or the session ended.

src/Plugins/BotSharp.Plugin.Twilio/Services/ConversationRelaySession.cs

[Copilot]

🟡 Changes recommended

An empty interruption prefix is treated as a missing playback boundary, leaving fully sent replies unmarked as unheard in conversation history even when the caller heard none of the reply.

1 open issue

• Treat an empty interruption prefix as an unheard reply · New

What changed in this PR

This follow-up to #1467 refines how Twilio interruptions are recorded in conversation history, using playback progress rather than only the text sent.

Changes:

• Use utteranceUntilInterrupt to locate the cut-off point, with a logged fallback to the sent text.
• Prevent interrupts from marking replies after the stream was dropped or the session ended.
• Reset playback-boundary tracking for each turn and update the documentation.

File	Description
src/​Plugins/​BotSharp.Plugin.Twilio/​Services/​ConversationRelaySession.cs	Tracks playback boundaries and tightens interruption handling for history updates.

_{Review effort: Balanced}

[Copilot]

🟢 Approval recommended

There are no active review issues for the Twilio interruption-handling changes.

No open issues 🎉

1 resolved since last review

• Treat an empty interruption prefix as an unheard reply

_{Review effort: Balanced}

[yileicn]

reviewed