fix asr error notify wrong vendor name (#728)

* asr/tts fallback

* add notification

* add notification

* wip

* wip

* wip

* wip

* wip

* wip

* wip

* wip

lib/session/call-session.js

@@ -113,11 +113,13 @@ class CallSession extends Emitter {
       this.requestor.on('command', this._onCommand.bind(this));
       this.requestor.on('connection-dropped', this._onWsConnectionDropped.bind(this));
       this.requestor.on('handover', handover.bind(this));
+      this.requestor.on('reconnect-error', this._onSessionReconnectError.bind(this));
     };
 
     this.requestor.on('command', this._onCommand.bind(this));
     this.requestor.on('connection-dropped', this._onWsConnectionDropped.bind(this));
     this.requestor.on('handover', handover.bind(this));
+    this.requestor.on('reconnect-error', this._onSessionReconnectError.bind(this));
   }
 
   /**
@@ -188,6 +190,24 @@ class CallSession extends Emitter {
     this._synthesizer = synth;
   }
 
+  /**
+   * ASR TTS fallback
+   */
+  get hasFallbackAsr() {
+    return this._hasFallbackAsr || false;
+  }
+
+  set hasFallbackAsr(i) {
+    this._hasFallbackAsr = i;
+  }
+
+  get hasFallbackTts() {
+    return this._hasFallbackTts || false;
+  }
+
+  set hasFallbackTts(i) {
+    this._hasFallbackTts = i;
+  }
   /**
    * default vendor to use for speech synthesis if not provided in the app
    */
@@ -1557,6 +1577,22 @@ Duration=${duration} `
     }, 'CallSession:_injectTasks - completed');
   }
 
+  async _onSessionReconnectError(err) {
+    const {writeAlerts, AlertType} = this.srf.locals;
+    const sid = this.accountInfo.account.account_sid;
+    this.logger.info({err}, `_onSessionReconnectError for account ${sid}`);
+    try {
+      await writeAlerts({
+        alert_type: AlertType.WEBHOOK_CONNECTION_FAILURE,
+        account_sid: this.accountSid,
+        detail: `Session:reconnect error ${err}`
+      });
+    } catch (error) {
+      this.logger.error({error}, 'Error writing WEBHOOK_CONNECTION_FAILURE alert');
+    }
+    this._jambonzHangup();
+  }
+
   _onCommand({msgid, command, call_sid, queueCommand, data}) {
     this.logger.info({msgid, command, queueCommand, data}, 'CallSession:_onCommand - received command');
     let resolution;
@@ -1832,6 +1868,7 @@ Duration=${duration} `
   /**
    * called when the caller has hung up.  Provided for subclasses to override
    * in order to apply logic at this point if needed.
+   * return true if success fallback, return false if not
    */
   _callerHungup() {
     assert(false, 'subclass responsibility to override this method');
@@ -2269,6 +2306,7 @@ Duration=${duration} `
 
   _startActionHookNoResponseTimer(options) {
     this._clearActionHookNoResponseTimer();
+    this._actionHookDelayResolved = false;
     if (options.noResponseTimeoutMs) {
       this.logger.debug(`CallSession:_startActionHookNoResponseTimer ${options.noResponseTimeoutMs}`);
       this._actionHookNoResponseTimer = setTimeout(() => {
@@ -2282,7 +2320,9 @@ Duration=${duration} `
         if (t.length) {
           t[0].on('playDone', (err) => {
             if (err) this.logger.error({err}, `Call-Session:exec Error delay action, play ${verb}`);
-            this._startActionHookNoResponseTimer(options);
+            if (!this._actionHookDelayResolved) {
+              this._startActionHookNoResponseTimer(options);
+            }
           });
         }
         this.tasks.push(...t);
@@ -2300,7 +2340,16 @@ Duration=${duration} `
 
   _clearActionHookNoResponseTimer() {
     if (this._actionHookNoResponseTimer) {
+      // Action Hook delay is solved.
+      this._actionHookDelayResolved = true;
       clearTimeout(this._actionHookNoResponseTimer);
+      // if delay action is enabled
+      // and bot has responded with list of new verbs
+      // Only kill current running play task.
+      //https://github.com/jambonz/jambonz-feature-server/issues/710
+      if (this.currentTask?.name === TaskName.Play) {
+        this.currentTask.kill(this);
+      }
     }
     this._actionHookNoResponseTimer = null;
   }

lib/tasks/config.js

@@ -250,8 +250,7 @@ class TaskConfig extends Task {
         cs.stopBackgroundTask('transcribe');
       }
     }
-
-    if (this.actionHookDelayAction) {
+    if (Object.keys(this.actionHookDelayAction).length !== 0) {
       cs.actionHookDelayEnabled = this.actionHookDelayAction.enabled || false;
       cs.actionHookNoResponseTimeout = this.actionHookDelayAction.noResponseTimeout || 0;
       cs.actionHookNoResponseGiveUpTimeout = this.actionHookDelayAction.noResponseGiveUpTimeout || 0;

lib/tasks/gather.js

@@ -174,12 +174,7 @@ class TaskGather extends SttTask {
           this._startTranscribing(ep);
           return updateSpeechCredentialLastUsed(this.sttCredentials.speech_credential_sid);
         } catch (e) {
-          if (this.fallbackVendor && this.isHandledByPrimaryProvider) {
-            await this._fallback();
-            startListening(cs, ep);
-          } else {
-            this.logger.error({error: e}, 'error in initSpeech');
-          }
+          await this._startFallback(cs, ep, {error: e});
         }
       }
     };
@@ -187,12 +182,7 @@ class TaskGather extends SttTask {
     try {
       if (this.sayTask) {
         const {span, ctx} = this.startChildSpan(`nested:${this.sayTask.summary}`);
-        this.sayTask.span = span;
-        this.sayTask.ctx = ctx;
-        this.sayTask.exec(cs, {ep});  // kicked off, _not_ waiting for it to complete
-        this.sayTask.on('playDone', (err) => {
-          span.end();
-          if (err) this.logger.error({err}, 'Gather:exec Error playing tts');
+        const process = () => {
           this.logger.debug('Gather: nested say task completed');
           if (!this.killed) {
             startListening(cs, ep);
@@ -203,16 +193,22 @@ class TaskGather extends SttTask {
               });
             }
           }
+        };
+        this.sayTask.span = span;
+        this.sayTask.ctx = ctx;
+        this.sayTask.exec(cs, {ep})  // kicked off, _not_ waiting for it to complete
+          .catch((err) => {
+            process();
+          });
+        this.sayTask.on('playDone', (err) => {
+          span.end();
+          if (err) this.logger.error({err}, 'Gather:exec Error playing tts');
+          process();
         });
       }
       else if (this.playTask) {
         const {span, ctx} = this.startChildSpan(`nested:${this.playTask.summary}`);
-        this.playTask.span = span;
-        this.playTask.ctx = ctx;
-        this.playTask.exec(cs, {ep});  // kicked off, _not_ waiting for it to complete
-        this.playTask.on('playDone', (err) => {
-          span.end();
-          if (err) this.logger.error({err}, 'Gather:exec Error playing url');
+        const process = () => {
           this.logger.debug('Gather: nested play task completed');
           if (!this.killed) {
             startListening(cs, ep);
@@ -223,6 +219,17 @@ class TaskGather extends SttTask {
               });
             }
           }
+        };
+        this.playTask.span = span;
+        this.playTask.ctx = ctx;
+        this.playTask.exec(cs, {ep})  // kicked off, _not_ waiting for it to complete
+          .catch((err) => {
+            process();
+          });
+        this.playTask.on('playDone', (err) => {
+          span.end();
+          if (err) this.logger.error({err}, 'Gather:exec Error playing url');
+          process();
         });
       }
       else {
@@ -894,9 +901,9 @@ class TaskGather extends SttTask {
   _onTranscriptionComplete(cs, ep) {
     this.logger.debug('TaskGather:_onTranscriptionComplete');
   }
-  async _onJambonzError(cs, ep, evt) {
-    this.logger.info({evt}, 'TaskGather:_onJambonzError');
-    if (this.isHandledByPrimaryProvider && this.fallbackVendor) {
+
+  async _startFallback(cs, ep, evt) {
+    if (this.canFallback) {
       ep.stopTranscription({
         vendor: this.vendor,
         bugname: this.bugname
@@ -904,17 +911,35 @@ class TaskGather extends SttTask {
         .catch((err) => this.logger.error({err}, `Error stopping transcription for primary vendor ${this.vendor}`));
       const {updateSpeechCredentialLastUsed} = require('../utils/db-utils')(this.logger, cs.srf);
       try {
-        await this._fallback();
-        await this._initSpeech(cs, ep);
+        this.logger.debug('gather:_startFallback');
+        this.notifyError({ msg: 'ASR error',
+          details:`STT Vendor ${this.vendor} error: ${evt.error || evt.reason}`, failover: 'in progress'});
+        await this._initFallback();
+        this._speechHandlersSet = false;
+        await this._setSpeechHandlers(cs, ep);
         this._startTranscribing(ep);
         updateSpeechCredentialLastUsed(this.sttCredentials.speech_credential_sid);
-        return;
+        return true;
       } catch (error) {
         this.logger.info({error}, `There is error while falling back to ${this.fallbackVendor}`);
+        this.notifyError({ msg: 'ASR error',
+          details:`STT Vendor ${this.vendor} error: ${evt.error || evt.reason}`, failover: 'not available'});
       }
+    } else {
+      this.logger.debug('gather:_startFallback no condition for falling back');
+      this.notifyError({ msg: 'ASR error',
+        details:`STT Vendor ${this.vendor} error: ${evt.error || evt.reason}`, failover: 'not available'});
     }
-    const {writeAlerts, AlertType} = cs.srf.locals;
+    return false;
+  }
 
+  async _onJambonzError(cs, ep, evt) {
+    if (this.vendor === 'google' && evt.error_code === 0) {
+      this.logger.info({evt}, 'TaskTranscribe:_onJambonzError - ignoring google error code 0');
+      return;
+    }
+    this.logger.info({evt}, 'TaskGather:_onJambonzError');
+    const {writeAlerts, AlertType} = cs.srf.locals;
     if (this.vendor === 'nuance') {
       const {code, error} = evt;
       if (code === 404 && error === 'No speech') return this._resolve('timeout');
@@ -927,17 +952,23 @@ class TaskGather extends SttTask {
       message: `Custom speech vendor ${this.vendor} error: ${evt.error}`,
       vendor: this.vendor,
     }).catch((err) => this.logger.info({err}, 'Error generating alert for jambonz custom connection failure'));
-    this.notifyError({msg: 'ASR error', details:`Custom speech vendor ${this.vendor} error: ${evt.error}`});
+    if (!(await this._startFallback(cs, ep, evt))) {
+      this.notifyTaskDone();
+    }
   }
 
-  _onVendorConnectFailure(cs, _ep, evt) {
+  async _onVendorConnectFailure(cs, _ep, evt) {
     super._onVendorConnectFailure(cs, _ep, evt);
-    this.notifyTaskDone();
+    if (!(await this._startFallback(cs, _ep, evt))) {
+      this.notifyTaskDone();
+    }
   }
 
-  _onVendorError(cs, _ep, evt) {
+  async _onVendorError(cs, _ep, evt) {
     super._onVendorError(cs, _ep, evt);
-    this._resolve('stt-error', evt);
+    if (!(await this._startFallback(cs, _ep, evt))) {
+      this._resolve('stt-error', evt);
+    }
   }
 
   _onVadDetected(cs, ep) {

lib/tasks/say.js

@@ -117,10 +117,6 @@ class TaskSay extends Task {
           alert_type: AlertType.TTS_NOT_PROVISIONED,
           vendor
         }).catch((err) => this.logger.info({err}, 'Error generating alert for no tts'));
-        this.notifyError({
-          msg: 'TTS error',
-          details:`No speech credentials provisioned for selected vendor ${vendor}`
-        });
         throw new Error('no provisioned speech credentials for TTS');
       }
       // synthesize all of the text elements
@@ -192,7 +188,6 @@ class TaskSay extends Task {
             vendor,
             detail: err.message
           }).catch((err) => this.logger.info({err}, 'Error generating alert for tts failure'));
-          this.notifyError({msg: 'TTS error', details: err.message || err});
           throw err;
         }
       };
@@ -215,16 +210,16 @@ class TaskSay extends Task {
     await super.exec(cs);
     this.ep = ep;
 
-    const vendor = this.synthesizer.vendor && this.synthesizer.vendor !== 'default' ?
+    let vendor = this.synthesizer.vendor && this.synthesizer.vendor !== 'default' ?
       this.synthesizer.vendor :
       cs.speechSynthesisVendor;
-    const language = this.synthesizer.language && this.synthesizer.language !== 'default' ?
+    let language = this.synthesizer.language && this.synthesizer.language !== 'default' ?
       this.synthesizer.language :
       cs.speechSynthesisLanguage ;
-    const voice =  this.synthesizer.voice && this.synthesizer.voice !== 'default' ?
+    let voice =  this.synthesizer.voice && this.synthesizer.voice !== 'default' ?
       this.synthesizer.voice :
       cs.speechSynthesisVoice;
-    const label = this.synthesizer.label && this.synthesizer.label !== 'default' ?
+    let label = this.synthesizer.label && this.synthesizer.label !== 'default' ?
       this.synthesizer.label :
       cs.speechSynthesisLabel;
 
@@ -241,12 +236,22 @@ class TaskSay extends Task {
       this.synthesizer.fallbackLabel :
       cs.fallbackSpeechSynthesisLabel;
 
+    if (cs.hasFallbackTts) {
+      vendor = fallbackVendor;
+      language = fallbackLanguage;
+      voice = fallbackVoice;
+      label = fallbackLabel;
+    }
+
     let filepath;
     try {
       filepath = await this._synthesizeWithSpecificVendor(cs, ep, {vendor, language, voice, label});
     } catch (error) {
-      if (fallbackVendor && this.isHandledByPrimaryProvider) {
+      if (fallbackVendor && this.isHandledByPrimaryProvider && !cs.hasFallbackTts) {
+        this.notifyError(
+          { msg: 'TTS error', details:`TTS vendor ${vendor} error: ${error}`, failover: 'in progress'});
         this.isHandledByPrimaryProvider = false;
+        cs.hasFallbackTts = true;
         this.logger.info(`Synthesize error, fallback to ${fallbackVendor}`);
         filepath = await this._synthesizeWithSpecificVendor(cs, ep,
           {
@@ -256,6 +261,8 @@ class TaskSay extends Task {
             label: fallbackLabel
           });
       } else {
+        this.notifyError(
+          { msg: 'TTS error', details:`TTS vendor ${vendor} error: ${error}`, failover: 'not available'});
         throw error;
       }
     }

lib/tasks/stt-task.js

@@ -102,6 +102,13 @@ class SttTask extends Task {
       this.fallbackLabel = cs.fallbackSpeechRecognizerLabel;
       if (this.data.recognizer) this.data.recognizer.fallbackLabel = this.fallbackLabel;
     }
+    // If call is already fallback to 2nd ASR vendor
+    // use that.
+    if (cs.hasFallbackAsr) {
+      this.vendor = this.fallbackVendor;
+      this.language = this.fallbackLanguage;
+      this.label = this.fallbackLabel;
+    }
     if (!this.data.recognizer.vendor) {
       this.data.recognizer.vendor = this.vendor;
     }
@@ -119,9 +126,19 @@ class SttTask extends Task {
       try {
         this.sttCredentials = await this._initSpeechCredentials(this.cs, this.vendor, this.label);
       } catch (error) {
-        if (this.fallbackVendor && this.isHandledByPrimaryProvider) {
-          await this._fallback();
+        if (this.canFallback) {
+          this.notifyError(
+            {
+              msg: 'ASR error', details:`Invalid vendor ${this.vendor}, Error: ${error}`,
+              failover: 'in progress'
+            });
+          await this._initFallback();
         } else {
+          this.notifyError(
+            {
+              msg: 'ASR error', details:`Invalid vendor ${this.vendor}, Error: ${error}`,
+              failover: 'not available'
+            });
           throw error;
         }
       }
@@ -164,11 +181,6 @@ class SttTask extends Task {
         alert_type: AlertType.STT_NOT_PROVISIONED,
         vendor
       }).catch((err) => this.logger.info({err}, 'Error generating alert for no stt'));
-      // Notify application that STT vender is wrong.
-      this.notifyError({
-        msg: 'ASR error',
-        details: `No speech-to-text service credentials for ${vendor} have been configured`
-      });
       this.notifyTaskDone();
       throw new Error(`No speech-to-text service credentials for ${vendor} have been configured`);
     }
@@ -190,9 +202,14 @@ class SttTask extends Task {
     return credentials;
   }
 
-  async _fallback() {
+  get canFallback() {
+    return this.fallbackVendor && this.isHandledByPrimaryProvider && !this.cs.hasFallbackAsr;
+  }
+
+  async _initFallback() {
     assert(this.fallbackVendor, 'fallback failed without fallbackVendor configuration');
     this.isHandledByPrimaryProvider = false;
+    this.cs.hasFallbackAsr = true;
     this.logger.info(`Failed to use primary STT provider, fallback to ${this.fallbackVendor}`);
     this.vendor = this.fallbackVendor;
     this.language = this.fallbackLanguage;
@@ -201,6 +218,8 @@ class SttTask extends Task {
     this.data.recognizer.language = this.language;
     this.data.recognizer.label = this.label;
     this.sttCredentials = await this._initSpeechCredentials(this.cs, this.vendor, this.label);
+    // cleanup previous listener from previous vendor
+    this.removeCustomEventListeners();
   }
 
   async compileHintsForCobalt(ep, hostport, model, token, hints) {
@@ -263,7 +282,6 @@ class SttTask extends Task {
       detail: evt.error,
       vendor: this.vendor,
     }).catch((err) => this.logger.info({err}, `Error generating alert for ${this.vendor} connection failure`));
-    this.notifyError({msg: 'ASR error', details:`Failed connecting to speech vendor ${this.vendor}: ${evt.error}`});
   }
 
   _onVendorConnectFailure(cs, _ep, evt) {
@@ -276,7 +294,6 @@ class SttTask extends Task {
       message: `Failed connecting to ${this.vendor} speech recognizer: ${reason}`,
       vendor: this.vendor,
     }).catch((err) => this.logger.info({err}, `Error generating alert for ${this.vendor} connection failure`));
-    this.notifyError({msg: 'ASR error', details:`Failed connecting to speech vendor ${this.vendor}: ${reason}`});
   }
 }
 

lib/tasks/transcribe.js

@@ -44,7 +44,7 @@ class TaskTranscribe extends SttTask {
       this.isContinuousAsr = true;
     }
     /* buffer speech for continuous asr */
-    this._bufferedTranscripts = [];
+    this._bufferedTranscripts = [ [], [] ];  // for channel 1 and 2
     this.bugname_prefix = 'transcribe_';
     this.paused = false;
   }
@@ -80,12 +80,15 @@ class TaskTranscribe extends SttTask {
 
       updateSpeechCredentialLastUsed(this.sttCredentials.speech_credential_sid)
         .catch(() => {/*already logged error */});
-
-      await this.awaitTaskDone();
     } catch (err) {
-      this.logger.info(err, 'TaskTranscribe:exec - error');
-      this.parentTask && this.parentTask.emit('error', err);
+      if (!(await this._startFallback(cs, ep, {error: err}))) {
+        this.logger.info(err, 'TaskTranscribe:exec - error');
+        this.parentTask && this.parentTask.emit('error', err);
+        this.removeCustomEventListeners();
+        return;
+      }
     }
+    await this.awaitTaskDone();
     this.removeCustomEventListeners();
   }
 
@@ -303,24 +306,26 @@ class TaskTranscribe extends SttTask {
   async _onTranscription(cs, ep, channel, evt, fsEvent) {
     // make sure this is not a transcript from answering machine detection
     const bugname = fsEvent.getHeader('media-bugname');
+    const finished = fsEvent.getHeader('transcription-session-finished');
+    const bufferedTranscripts = this._bufferedTranscripts[channel - 1];
     if (bugname && this.bugname !== bugname) return;
     if (this.paused) {
       this.logger.debug({evt}, 'TaskTranscribe:_onTranscription - paused, ignoring transcript');
     }
 
-
     if (this.vendor === 'ibm' && evt?.state === 'listening') return;
 
     if (this.vendor === 'deepgram' && evt.type === 'UtteranceEnd') {
       /* we will only get this when we have set utterance_end_ms */
-      if (this._bufferedTranscripts.length === 0) {
+      if (bufferedTranscripts.length === 0) {
         this.logger.debug('Gather:_onTranscription - got UtteranceEnd event from deepgram but no buffered transcripts');
       }
       else {
         this.logger.debug('Gather:_onTranscription - got UtteranceEnd event from deepgram, return buffered transcript');
-        evt = this.consolidateTranscripts(this._bufferedTranscripts, 1, this.language, this.vendor);
-        this._bufferedTranscripts = [];
-        this._resolve('speech', evt);
+        evt = this.consolidateTranscripts(bufferedTranscripts, channel, this.language, this.vendor);
+        evt.is_final = true;
+        this._bufferedTranscripts[channel - 1] = [];
+        this._resolve(channel, evt);
       }
       return;
     }
@@ -334,31 +339,89 @@ class TaskTranscribe extends SttTask {
       return;
     }
 
-    if (evt.alternatives[0]?.transcript === '' && !cs.callGone && !this.killed) {
-      if (['microsoft', 'deepgram'].includes(this.vendor)) {
-        this.logger.info({evt}, 'TaskTranscribe:_onTranscription - got empty transcript, continue listening');
+    let emptyTranscript = false;
+    if (evt.is_final) {
+      if (evt.alternatives.length === 0 || evt.alternatives[0].transcript === '' && !cs.callGone && !this.killed) {
+        emptyTranscript = true;
+        if (finished === 'true' &&
+          ['microsoft', 'deepgram'].includes(this.vendor) &&
+          bufferedTranscripts.length === 0) {
+          this.logger.debug({evt}, 'TaskGather:_onTranscription - got empty transcript from old gather, disregarding');
+          return;
+        }
+        else if (this.vendor !== 'deepgram') {
+          this.logger.info({evt}, 'TaskGather:_onTranscription - got empty transcript, continue listening');
+          return;
+        }
+        else if (this.isContinuousAsr) {
+          this.logger.info({evt},
+            'TaskGather:_onTranscription - got empty deepgram transcript during continous asr, continue listening');
+          return;
+        }
+        else if (this.vendor === 'deepgram' && bufferedTranscripts.length > 0) {
+          this.logger.info({evt},
+            'TaskGather:_onTranscription - got empty transcript from deepgram, return the buffered transcripts');
+        }
+      }
+      if (this.isContinuousAsr) {
+        /* append the transcript and start listening again for asrTimeout */
+        const t = evt.alternatives[0].transcript;
+        if (t) {
+          /* remove trailing punctuation */
+          if (/[,;:\.!\?]$/.test(t)) {
+            this.logger.debug('TaskGather:_onTranscription - removing trailing punctuation');
+            evt.alternatives[0].transcript = t.slice(0, -1);
+          }
+        }
+        this.logger.info({evt}, 'TaskGather:_onTranscription - got transcript during continous asr');
+        bufferedTranscripts.push(evt);
+        this._startAsrTimer(channel);
+
+        /* some STT engines will keep listening after a final response, so no need to restart */
+        if (!['soniox', 'aws', 'microsoft', 'deepgram', 'google']
+          .includes(this.vendor)) this._startTranscribing(cs, ep, channel);
       }
       else {
-        this.logger.info({evt}, 'TaskTranscribe:_onTranscription - got empty transcript, listen again');
-        this._transcribe(ep);
-      }
-      return;
-    }
+        if (this.vendor === 'soniox') {
+          /* compile transcripts into one */
+          this._sonioxTranscripts.push(evt.vendor.finalWords);
+          evt = this.compileSonioxTranscripts(this._sonioxTranscripts, 1, this.language);
+          this._sonioxTranscripts = [];
+        }
+        else if (this.vendor === 'deepgram') {
+          /* compile transcripts into one */
+          if (!emptyTranscript) bufferedTranscripts.push(evt);
 
-    if (this.vendor === 'soniox') {
-      /* compile transcripts into one */
-      this._sonioxTranscripts.push(evt.vendor.finalWords);
-      if (evt.is_final) {
-        evt = this.compileSonioxTranscripts(this._sonioxTranscripts, 1, this.language);
-        this._sonioxTranscripts = [];
+          /* deepgram can send an empty and final transcript; only if we have any buffered should we resolve */
+          if (bufferedTranscripts.length === 0) return;
+          evt = this.consolidateTranscripts(bufferedTranscripts, channel, this.language);
+          this._bufferedTranscripts[channel - 1] = [];
+        }
+
+        /* here is where we return a final transcript */
+        this.logger.debug({evt}, 'TaskTranscribe:_onTranscription - sending final transcript');
+        this._resolve(channel, evt);
+        /* some STT engines will keep listening after a final response, so no need to restart */
+        if (!['soniox', 'aws', 'microsoft', 'deepgram', 'google']
+          .includes(this.vendor)) this._startTranscribing(cs, ep, channel);
       }
     }
+    else {
+      /* interim transcript */
 
-    if (this.isContinuousAsr && evt.is_final) {
-      this._bufferedTranscripts.push(evt);
-      this._startAsrTimer(channel);
-    } else {
-      await this._resolve(channel, evt);
+      /* deepgram can send a non-final transcript but with words that are final, so we need to buffer */
+      if (this.vendor === 'deepgram') {
+        const originalEvent = evt.vendor.evt;
+        if (originalEvent.is_final && evt.alternatives[0].transcript !== '') {
+          this.logger.debug({evt}, 'Gather:_onTranscription - buffering a completed (partial) deepgram transcript');
+          bufferedTranscripts.push(evt);
+        }
+      }
+
+      if (this.interim) {
+        this.logger.debug({evt}, 'TaskTranscribe:_onTranscription - sending interim transcript');
+        this._resolve(channel, evt);
+      }
     }
   }
 
@@ -452,10 +515,8 @@ class TaskTranscribe extends SttTask {
     }
   }
 
-  async _onJambonzError(cs, _ep, evt) {
-    this.logger.info({evt}, 'TaskTranscribe:_onJambonzError');
-    if (this.paused) return;
-    if (this.isHandledByPrimaryProvider && this.fallbackVendor) {
+  async _startFallback(cs, _ep, evt) {
+    if (this.canFallback) {
       _ep.stopTranscription({
         vendor: this.vendor,
         bugname: this.bugname
@@ -463,37 +524,57 @@ class TaskTranscribe extends SttTask {
         .catch((err) => this.logger.error({err}, `Error stopping transcription for primary vendor ${this.vendor}`));
       const {updateSpeechCredentialLastUsed} = require('../utils/db-utils')(this.logger, cs.srf);
       try {
-        await this._fallback();
+        this.notifyError({ msg: 'ASR error',
+          details:`STT Vendor ${this.vendor} error: ${evt.error || evt.reason}`, failover: 'in progress'});
+        await this._initFallback();
         let channel = 1;
         if (this.ep !== _ep) {
           channel = 2;
         }
+        this[`_speechHandlersSet_${channel}`] = false;
         this._startTranscribing(cs, _ep, channel);
         updateSpeechCredentialLastUsed(this.sttCredentials.speech_credential_sid);
-        return;
+        return true;
       } catch (error) {
+        this.notifyError({ msg: 'ASR error',
+          details:`STT Vendor ${this.vendor} error: ${evt.error || evt.reason}`, failover: 'not available'});
         this.logger.info({error}, `There is error while falling back to ${this.fallbackVendor}`);
       }
     } else {
-      const {writeAlerts, AlertType} = cs.srf.locals;
+      this.logger.debug('transcribe:_startFallback no condition for falling back');
+      this.notifyError({ msg: 'ASR error',
+        details:`STT Vendor ${this.vendor} error: ${evt.error || evt.reason}`, failover: 'not available'});
+    }
+    return false;
+  }
 
-      if (this.vendor === 'nuance') {
-        const {code, error} = evt;
-        if (code === 404 && error === 'No speech') return this._resolve('timeout');
-        if (code === 413 && error === 'Too much speech') return this._resolve('timeout');
-      }
-      this.logger.info({evt}, 'TaskTranscribe:_onJambonzError');
-      writeAlerts({
-        account_sid: cs.accountSid,
-        alert_type: AlertType.STT_FAILURE,
-        message: `Custom speech vendor ${this.vendor} error: ${evt.error}`,
-        vendor: this.vendor,
-      }).catch((err) => this.logger.info({err}, 'Error generating alert for jambonz custom connection failure'));
-      this.notifyError({msg: 'ASR error', details:`Custom speech vendor ${this.vendor} error: ${evt.error}`});
+  async _onJambonzError(cs, _ep, evt) {
+    if (this.vendor === 'google' && evt.error_code === 0) {
+      this.logger.info({evt}, 'TaskTranscribe:_onJambonzError - ignoring google error code 0');
+      return;
+    }
+    this.logger.info({evt}, 'TaskTranscribe:_onJambonzError');
+    if (this.paused) return;
+    const {writeAlerts, AlertType} = cs.srf.locals;
+
+    if (this.vendor === 'nuance') {
+      const {code, error} = evt;
+      if (code === 404 && error === 'No speech') return this._resolve('timeout');
+      if (code === 413 && error === 'Too much speech') return this._resolve('timeout');
+    }
+    this.logger.info({evt}, 'TaskTranscribe:_onJambonzError');
+    writeAlerts({
+      account_sid: cs.accountSid,
+      alert_type: AlertType.STT_FAILURE,
+      message: `Custom speech vendor ${this.vendor} error: ${evt.error}`,
+      vendor: this.vendor,
+    }).catch((err) => this.logger.info({err}, 'Error generating alert for jambonz custom connection failure'));
+    if (!(await this._startFallback(cs, _ep, evt))) {
+      this.notifyTaskDone();
     }
   }
 
-  _onVendorConnectFailure(cs, _ep, channel, evt) {
+  async _onVendorConnectFailure(cs, _ep, channel, evt) {
     super._onVendorConnectFailure(cs, _ep, evt);
     if (this.childSpan[channel - 1] && this.childSpan[channel - 1].span) {
       this.childSpan[channel - 1].span.setAttributes({
@@ -502,7 +583,9 @@ class TaskTranscribe extends SttTask {
       });
       this.childSpan[channel - 1].span.end();
     }
-    this.notifyTaskDone();
+    if (!(await this._startFallback(cs, _ep, evt))) {
+      this.notifyTaskDone();
+    }
   }
 
   _startAsrTimer(channel) {
@@ -511,8 +594,9 @@ class TaskTranscribe extends SttTask {
     this._clearAsrTimer(channel);
     this._asrTimer = setTimeout(() => {
       this.logger.debug(`TaskTranscribe:_startAsrTimer - asr timer went off for channel: ${channel}`);
-      const evt = this.consolidateTranscripts(this._bufferedTranscripts, channel, this.language, this.vendor);
-      this._bufferedTranscripts = [];
+      const evt = this.consolidateTranscripts(
+        this._bufferedTranscripts[channel - 1], channel, this.language, this.vendor);
+      this._bufferedTranscripts[channel - 1] = [];
       this._resolve(channel, evt);
     }, this.asrTimeout);
     this.logger.debug(`TaskTranscribe:_startAsrTimer: set for ${this.asrTimeout}ms for channel ${channel}`);

lib/utils/transcription-utils.js

@@ -270,7 +270,7 @@ const normalizeDeepgram = (evt, channel, language, shortUtterance) => {
     language_code: language,
     channel_tag: channel,
     is_final: shortUtterance ? evt.is_final : evt.speech_final,
-    alternatives: [alternatives[0]],
+    alternatives: alternatives.length ? [alternatives[0]] : [],
     vendor: {
       name: 'deepgram',
       evt: copy

lib/utils/ws-requestor.js

@@ -56,6 +56,12 @@ class WsRequestor extends BaseRequestor {
     }
 
     if (type === 'session:new') this.call_sid = params.callSid;
+    if (type === 'session:reconnect') {
+      this._reconnectPromise = new Promise((resolve, reject) => {
+        this._reconnectResolve = resolve;
+        this._reconnectReject = reject;
+      });
+    }
 
     /* if we have an absolute url, and it is http then do a standard webhook */
     if (this._isAbsoluteUrl(url) && url.startsWith('http')) {
@@ -71,20 +77,23 @@ class WsRequestor extends BaseRequestor {
     }
 
     /* connect if necessary */
+    const queueMsg = () => {
+      this.logger.debug(
+        `WsRequestor:request(${this.id}) - queueing ${type} message since we are connecting`);
+      if (wantsAck) {
+        const p = new Promise((resolve, reject) => {
+          this.queuedMsg.push({type, hook, params, httpHeaders, promise: {resolve, reject}});
+        });
+        return p;
+      }
+      else {
+        this.queuedMsg.push({type, hook, params, httpHeaders});
+      }
+      return;
+    };
     if (!this.ws) {
       if (this.connectInProgress) {
-        this.logger.debug(
-          `WsRequestor:request(${this.id}) - queueing ${type} message since we are connecting`);
-        if (wantsAck) {
-          const p = new Promise((resolve, reject) => {
-            this.queuedMsg.push({type, hook, params, httpHeaders, promise: {resolve, reject}});
-          });
-          return p;
-        }
-        else {
-          this.queuedMsg.push({type, hook, params, httpHeaders});
-        }
-        return;
+        return queueMsg();
       }
       this.connectInProgress = true;
       this.logger.debug(`WsRequestor:request(${this.id}) - connecting since we do not have a connection for ${type}`);
@@ -102,6 +111,10 @@ class WsRequestor extends BaseRequestor {
         return Promise.reject(err);
       }
     }
+    // If jambonz wait for ack from reconnect, queue the msg until reconnect is acked
+    if (type !== 'session:reconnect' && this._reconnectPromise) {
+      return queueMsg();
+    }
     assert(this.ws);
 
     /* prepare and send message */
@@ -139,6 +152,18 @@ class WsRequestor extends BaseRequestor {
       }
     };
 
+    const rejectQueuedMsgs = (err) => {
+      if (this.queuedMsg.length > 0) {
+        for (const {promise} of this.queuedMsg) {
+          this.logger.debug(`WsRequestor:request - preparing queued ${type} for rejectQueuedMsgs`);
+          if (promise) {
+            promise.reject(err);
+          }
+        }
+        this.queuedMsg.length = 0;
+      }
+    };
+
     //this.logger.debug({obj}, `websocket: sending (${url})`);
 
     /* special case: reconnecting before we received ack to session:new */
@@ -179,16 +204,37 @@ class WsRequestor extends BaseRequestor {
           this.logger.debug({response}, `WsRequestor:request ${url} succeeded in ${rtt}ms`);
           this.stats.histogram('app.hook.ws_response_time', rtt, ['hook_type:app']);
           resolve(response);
+          if (this._reconnectResolve) {
+            this._reconnectResolve();
+          }
         },
         failure: (err) => {
+          if (this._reconnectReject) {
+            this._reconnectReject(err);
+          }
           clearTimeout(timer);
           reject(err);
         }
       });
 
       /* send the message */
-      this.ws.send(JSON.stringify(obj), () => {
+      this.ws.send(JSON.stringify(obj), async() => {
         this.logger.debug({obj}, `WsRequestor:request websocket: sent (${url})`);
+        // If session:reconnect is waiting for ack, hold here until ack to send queuedMsgs
+        if (this._reconnectPromise) {
+          try {
+            await this._reconnectPromise;
+          } catch (err) {
+            // bad thing happened to session:recconnect
+            rejectQueuedMsgs(err);
+            this.emit('reconnect-error');
+            return;
+          } finally {
+            this._reconnectPromise = null;
+            this._reconnectResolve = null;
+            this._reconnectReject = null;
+          }
+        }
         sendQueuedMsgs();
       });
     });