Visual Call Flow Builder

Orchestrate Smart Voice Routing, Drag, Drop & Deploy Without Writing Complex Code

Design intelligent IVR trees, AI Voice Agent handoffs, skills-based queues, and real-time CRM webhook automations on an infinite canvas with zero-downtime hot deploy.

Hot-deploy in < 1s with 0s downtime
13+ specialized telephony & AI nodes
Real-time high performance flow engine
Direct CRM & REST API webhook triggers
flow-engine.firetell.app
HOT-DEPLOY READY
Select Active Flow Scenario:
1
Inbound PSTN / SIP
+84 28 7300 8899
2
Contact Lookup
Salesforce VIP Gold
3Connect Voice Agent (AI)
< 300ms Latency
Branch: ResolvedHangup & Log to CRM
Branch: EscalateBridge Tier 2 Support
GRAPH VALIDATED & COMPILED
DAG Latency: 4.2ms
Telephony Node Ecosystem

13+ Specialized Telephony Nodes for Total Voice Orchestration

Every block is optimized for sub-10ms execution latency on the Firetell Telephony Engine.

Entry Trigger

Inbound / Outbound Call

Entry trigger for PSTN numbers, SIP trunks, or outbound campaign dialer batches.

Ultra-Low Latency Node
Early Media

Play Audio

Plays workspace media files with early-media ringback and audio caching support.

Ultra-Low Latency Node
DTMF IVR

Collect Digits (IVR)

Multi-key DTMF menu branching with custom inter-digit timeouts and speech prompts.

Ultra-Low Latency Node
Neural TTS

Text to Speech (TTS)

Neural voice synthesis across 40+ languages and studio voices in real-time.

Ultra-Low Latency Node
WebRTC / SIP

Connect Agent

Direct bridging to online WebRTC or SIP agents with customized ring timeout rules.

Ultra-Low Latency Node
Skill Queue

Connect Team

Skills-based queue routing with Round-Robin, Longest-Idle, and fallback branches.

Ultra-Low Latency Node
LLM Voice AI

Connect Voice Agent

Real-time AI Voice Bot integration (< 300ms latency) with warm transfer escalation.

Ultra-Low Latency Node
SIP URI / PBX

SIP Account

Direct routing to enterprise IP phones, softphones, or on-premise PBX gateways.

Ultra-Low Latency Node
Real-time Webhook

JSON Call Action (JCA)

Execute external HTTP webhooks mid-call to query databases or trigger backend workflows.

Ultra-Low Latency Node
CRM Sync

Contact Lookup

Instant caller profile resolution from Salesforce, HubSpot, or Firetell Contacts.

Ultra-Low Latency Node
Schedules

Business Hours

Timezone-aware operational schedule checks with Open, Closed, and Holiday branches.

Ultra-Low Latency Node
S3 Audio Drop

To Voicemail

Records caller voicemail with greeting prompt and delivers audio directly to S3 & email.

Ultra-Low Latency Node
SIP Terminate

Disconnect

Graceful call termination with standard SIP release causes (Normal, Busy, Rejected).

Ultra-Low Latency Node
Architecture Comparison

Legacy PBX Dialplans vs Firetell Visual Flow Engine

Why modern engineering and contact center teams choose Firetell.

Feature
Legacy Dialplan (Asterisk / XML)
Firetell Flow Builder
Flow Deployment & Updates
Requires PBX config edits & service reloads
0s Downtime Hot-Deploy on active calls
Voice AI & LLM Integration
Complex custom AGI/Lua socket scripts
1-Click 'Connect Voice Agent' node
Node Execution Latency
100ms - 500ms per step
< 10ms Firetell Flow Core execution
Graph Validation & Safety
Manual dialplan testing; runtime crashes
Automated DAG cycle & loop detection
Developer-First API & Webhooks

Programmatic Call Flow Automation

Deploy, trigger, and inspect call flows programmatically with our Server SDK and real-time webhook events.

import { FiretellServerClient } from '@firetell/firetell-server-sdk';

const firetell = new FiretellServerClient({
  apiKey: process.env.FIRETELL_API_KEY!,
  workspaceId: 'ws_prod_9924a'
});

// Trigger dynamic call flow on inbound call
const execution = await firetell.callFlows.execute({
  flowId: 'flow_support_triage_v2',
  to: '+84901234567',
  from: '+842873008899',
  variables: {
    customerTier: 'VIP_GOLD',
    language: 'vi-VN',
    crmLeadId: 'lead_99214'
  }
});

console.log('Call flow dispatched:', execution.id);
How It Works

Build and Ship Enterprise Flows in 3 Simple Steps

1. Drag & Connect Nodes

Place IVR menus, AI voice agents, and queue blocks on the visual canvas.

2. Configure Branches & Logic

Set business hours, DTMF digit routing, timeout failovers, and webhook URLs.

3. 1-Click Hot Publish

Validate DAG graph and publish instantly to production without restarting servers.

Frequently Asked Questions

Does updating a Call Flow interrupt ongoing customer calls?

No. Firetell uses atomic versioning and zero-downtime hot deploys. In-flight calls continue on their existing flow instance, while all new incoming calls instantly execute the newly published version.

How does the Call Flow Builder integrate with Voice AI Agents?

Simply drag the 'Connect Voice Agent' node onto your canvas. You can select your trained AI bot, configure welcome prompts, and define automated escalation branches to transfer calls to human queues when needed.

Can we execute custom backend API logic during a live call?

Yes. The 'JSON Call Action' (JCA) node sends an HTTP webhook to your API server and parses the returned JSON instructions (e.g. dynamic TTS messages or custom routing branch IDs) in real-time.

Can we manage and deploy Call Flows programmatically via API?

Absolutely. Everything in the builder is backed by our REST API and @firetell/firetell-server-sdk, allowing CI/CD pipeline automation, version rollback, and dynamic flow generation.

Ready to build intelligent call workflows in minutes?

Design, test, and publish your first visual call flow with zero coding required.