The communications
control plane

Compose AI agents, human agents, and real-time communications into one system you control in code. One programmable platform for everything that happens on a call. Built by the creators of FreeSWITCH.

Start building

Start building

Talk to an expert

Talk to an expert

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Trusted by forward-thinking companies

Trusted by forward-thinking companies

Trusted by forward-thinking companies

ARCHITECTURE

Production is a costly place to discover architectural mistakes

In staging, webhooks arrive fast and in order. Production is less polite. On SignalWire, state lives inside the call so that your code defines logic instead of managing event timing. The same architecture that works at 10 calls works at 10,000.

See the platform architecture →

Traditional CPaaS

Telephony vendor + WebRTC vendor + AI vendor

Your responsibility to rebuild state from events 

Endless race conditions

Rogue AI that won’t stay on task

Bolted on AI adds latency

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Platform

One Programmable Unified Communications platform

Calls are first-class objects with state attached 

The developer is in full control of call behavior

AI Agents follow code logic and stay on task

AI Kernel directly in the media stack for lowest latency

THE CODE

One engine. Fully programmable.

The platform handles state, timing, coordination, and infrastructure. You build AI agents and call flows, so your code spends its time on your product instead of the plumbing.

IVR and Call Routing

AI Voice Agents

Contact Center

01 Route by AI Voice

Get the DTMF out of here. The caller says what they need and the flow routes on it.

02 Route by Who’s Calling

Look the caller up and route on account, tier, or history. The lookup and the decision live in one flow, no orchestration layer between them.

03 Answering Machine Detection

Tell human, machine, and fax apart on outbound calls and branch on the result. It's a native verb, not a service you integrate and reconcile.

Route by AI Voice

copy

01 02 03 04 05 06 07 08 09 10 11 12

version: 1.0.0
sections:
  main:
    - prompt:
        play: ["say: In a few words, what are you calling about?"]
        # Speech in, not digits. What they say becomes the route.
        speech_language: en-US
        speech_hints: ["sales", "support", "billing"]
    - switch:
        variable: prompt_value
        case:
          sales:
            - connect: { to: "+15551112222" }
          support:
            - connect: { to: "+15553334444" }
          default:
            - connect: { to: "+15555556666"

IVR and Call Routing

Explore IVR and call routing →

IVR and Call Routing

AI Voice Agents

Contact Center

01 Route by AI Voice

Get the DTMF out of here. The caller says what they need and the flow routes on it.

02 Route by Who’s Calling

Look the caller up and route on account, tier, or history. The lookup and the decision live in one flow, no orchestration layer between them.

03 Answering Machine Detection

Tell human, machine, and fax apart on outbound calls and branch on the result. It's a native verb, not a service you integrate and reconcile.

Route by AI Voice

copy

01 02 03 04 05 06 07 08 09 10 11 12

version: 1.0.0
sections:
  main:
    - prompt:
        play: ["say: In a few words, what are you calling about?"]
        # Speech in, not digits. What they say becomes the route.
        speech_language: en-US
        speech_hints: ["sales", "support", "billing"]
    - switch:
        variable: prompt_value
        case:
          sales:
            - connect: { to: "+15551112222" }
          support:
            - connect: { to: "+15553334444" }
          default:
            - connect: { to: "+15555556666"

IVR and Call Routing

Explore IVR and call routing →

IVR and Call Routing

AI Voice Agents

Contact Center

01 Route by AI Voice

Get the DTMF out of here. The caller says what they need and the flow routes on it.

02 Route by Who’s Calling

Look the caller up and route on account, tier, or history. The lookup and the decision live in one flow, no orchestration layer between them.

03 Answering Machine Detection

Tell human, machine, and fax apart on outbound calls and branch on the result. It's a native verb, not a service you integrate and reconcile.

Route by AI Voice

copy

01 02 03 04 05 06 07 08 09 10 11 12

version: 1.0.0
sections:
  main:
    - prompt:
        play: ["say: In a few words, what are you calling about?"]
        # Speech in, not digits. What they say becomes the route.
        speech_language: en-US
        speech_hints: ["sales", "support", "billing"]
    - switch:
        variable: prompt_value
        case:
          sales:
            - connect: { to: "+15551112222" }
          support:
            - connect: { to: "+15553334444" }
          default:
            - connect: { to: "+15555556666"

IVR and Call Routing

Explore IVR and call routing →

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Built from the media engine up

The same team created FreeSWITCH, the media engine much of the industry runs on, then spent two decades building the platform around it, down to the carrier. Because we own that layer, the control plane goes all the way down. You're programming the network itself, not a wrapper over someone else's.

Start building

CONTROL PLANE

One programmable layer runs the whole call.

One programmable layer runs the whole call.

Voice, video, messaging, and AI run through one control plane. The call stays on the platform for its whole life instead of bouncing between vendors. Recording, queues, transfers, agents: whatever the session needs next is one instruction away.

Voice, video, messaging, and AI run through one control plane. The call stays on the platform for its whole life instead of bouncing between vendors. Recording, queues, transfers, agents: whatever the session needs next is one instruction away.

Explore the control plane →

SYSTEM-DIRECTED AI

You write the logic. Voice AI follows it.

Putting business logic in a prompt means hoping the model stays on script. A system-directed agent runs the conversation as a state machine of steps you define in code. At each step the model sees only the tools and data you expose. Off-script is not a state that exists.

greet

tools: none · next: collect

Instructions only.

collect

tools: check_calendar · next: confirm

Finds real openings.

confirm

tools: book_appointment · next: wrap_up

The software acts; the model only requests.

wrap_up

tools: none · next: none

Structurally complete.

The model makes it natural. Your code runs the show.

See how an agent is built →

Try it now

Talk it through with Sigmond

Sigmond is a voice AI agent running on the SignalWire infrastructure this page is about. Ask him about anything you just read.

Sigmond

Try it now

Talk it through with Sigmond

Sigmond is a voice AI agent running on the SignalWire infrastructure this page is about. Ask him about anything you just read.

Sigmond

Try it now

Talk it through with Sigmond

Sigmond is a voice AI agent running on the SignalWire infrastructure this page is about. Ask him about anything you just read.

Sigmond

CUSTOMER PROOF

Join the thousands of developers

  • Angular Gradient Image

    “It took us maybe a day to get a proof of concept working. ”

    Avatar

    Mark Lilien

    CTO at Textline

  • Angular Gradient Image

    “I was able to develop and ship the first version within 6 hours. Within 24 hours customers were signing up.”

    Avatar

    David Plappert

    Founder at PhoneLiveStreaming

  • Angular Gradient Image

    “We really appreciate the carrier-grade quality of service.”

    Avatar

    Murray Kawchuk

    Head of Strategy at Conversate

  • Angular Gradient Image

    “It took us maybe a day to get a proof of concept working. ”

    Avatar

    Mark Lilien

    CTO at Textline

  • Angular Gradient Image

    “I was able to develop and ship the first version within 6 hours. Within 24 hours customers were signing up.”

    Avatar

    David Plappert

    Founder at PhoneLiveStreaming

  • Angular Gradient Image

    “We really appreciate the carrier-grade quality of service.”

    Avatar

    Murray Kawchuk

    Head of Strategy at Conversate

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For Developers

Dive into documentation

From pip install to production. Guides, API references, and SDKs to start building complex communications flows.

Communications Platform

AI Voice Agents

SWML

Define voice, video, messaging, and AI flows in JSON or YAML. Built-in methods for every call primitive, served statically or generated per request.

Learn More

REST APIs

Every capability is a REST call: send an SMS, place a call, provision a number. Twilio-compatible, so existing code runs once you swap the credentials.

Learn More

Realtime SDKs

Control calls in real time over WebSocket with the RELAY SDKs. React to call events as they happen, in the language you already use.

Learn More

Top Linear Gradient Lines image

For Developers

Dive into documentation

From pip install to production. Guides, API references, and SDKs to start building complex communications flows.

Communications Platform

AI Voice Agents

SWML

Define voice, video, messaging, and AI flows in JSON or YAML. Built-in methods for every call primitive, served statically or generated per request.

Learn More

REST APIs

Every capability is a REST call: send an SMS, place a call, provision a number. Twilio-compatible, so existing code runs once you swap the credentials.

Learn More

Realtime SDKs

Control calls in real time over WebSocket with the RELAY SDKs. React to call events as they happen, in the language you already use.

Learn More

Top Linear Gradient Lines image

For Developers

Dive into documentation

From pip install to production. Guides, API references, and SDKs to start building complex communications flows.

Communications Platform

AI Voice Agents

SWML

Define voice, video, messaging, and AI flows in JSON or YAML. Built-in methods for every call primitive, served statically or generated per request.

Learn More

REST APIs

Every capability is a REST call: send an SMS, place a call, provision a number. Twilio-compatible, so existing code runs once you swap the credentials.

Learn More

Realtime SDKs

Control calls in real time over WebSocket with the RELAY SDKs. React to call events as they happen, in the language you already use.

Learn More

One platform for everything on the call

One platform for voice, AI, and messaging, on infrastructure that runs all the way down to the carrier. Every part of the call, programmable from one place.

Start building

Dive into docs

One platform for everything on the call

One platform for voice, AI, and messaging, on infrastructure that runs all the way down to the carrier. Every part of the call, programmable from one place.

Start building

Dive into docs

One platform for everything on the call

One platform for voice, AI, and messaging, on infrastructure that runs all the way down to the carrier. Every part of the call, programmable from one place.

Start building

Dive into docs

One platform for everything on the call

One platform for voice, AI, and messaging, on infrastructure that runs all the way down to the carrier. Every part of the call, programmable from one place.

Start building

Dive into docs