2,000+

companies in production

2.7B

minutes processed

< 1.2s

typical AI response latency

<10 min

to first phone call

The Infrastructure Gap

Your AI Speaks WebSocket. Phones Speak SIP.

SIP and RTP protocol bridging

Your WebSocket-native agent does not speak SIP signaling or RTP media streams. Bridging these protocols requires deep telephony expertise that most AI teams lack.

Phone number provisioning

Regulatory forms, identity verification, and carrier relationships. Getting a number that rings your AI is harder than building the AI itself.

Codec negotiation

G.711 at 8kHz over PSTN vs. Opus at 48kHz in your browser demo. Transcoding between them without degrading quality or adding latency.

Call control primitives

Transfers, hold, conferencing, recording, IVR fallback. Production calls need these capabilities, and your AI pipeline does not provide them.

Build a Voice AI Agent

from signalwire_agents import AgentBase
from signalwire_agents.core.function_result import SwaigFunctionResult

class SupportAgent(AgentBase):
    def __init__(self):
        super().__init__(name="Support Agent", route="/support")
        self.prompt_add_section("Instructions",
            body="You are a customer support agent. "
                 "Greet the caller and resolve their issue.")
        self.add_language("English", "en-US", "rime.spore:mistv2")

    @AgentBase.tool(name="check_order")
    def check_order(self, order_id: str):
        """Check the status of a customer order.

        Args:
            order_id: The order ID to look up
        """
        return SwaigFunctionResult(f"Order {order_id}: shipped, ETA April 2nd")

agent = SupportAgent()
agent.run()

import { AgentBase, FunctionResult } from '@signalwire/sdk';

const agent = new AgentBase({
  name: 'Support Agent',
  route: '/support',
});

agent.promptAddSection('Instructions',
  'You are a customer support agent. Greet the caller and resolve their issue.');

agent.addLanguage({ name: 'English', code: 'en-US', voice: 'rime.spore:mistv2' });

agent.defineTool({
  name: 'check_order',
  description: 'Check the status of a customer order',
  parameters: {
    type: 'object',
    properties: {
      order_id: { type: 'string', description: 'The order ID to look up' },
    },
    required: ['order_id'],
  },
  handler: (args) => {
    return new FunctionResult(`Order ${args.order_id}: shipped, ETA April 2nd`);
  },
});

agent.run();

package main

import (
	"fmt"

	"github.com/signalwire/signalwire-go/pkg/agent"
	"github.com/signalwire/signalwire-go/pkg/swaig"
)

func main() {
	a := agent.NewAgentBase(
		agent.WithName("Support Agent"),
		agent.WithRoute("/support"),
	)

	a.PromptAddSection("Instructions",
		"You are a customer support agent. Greet the caller and resolve their issue.")

	a.AddLanguage(map[string]any{
		"name": "English", "code": "en-US", "voice": "rime.spore:mistv2",
	})

	a.DefineTool(agent.ToolDefinition{
		Name:        "check_order",
		Description: "Check the status of a customer order",
		Parameters: map[string]any{
			"type": "object",
			"properties": map[string]any{
				"order_id": map[string]any{
					"type": "string", "description": "The order ID to look up",
				},
			},
			"required": []string{"order_id"},
		},
		Handler: func(args map[string]any, rawData map[string]any) *swaig.FunctionResult {
			orderID := args["order_id"]
			return swaig.NewFunctionResult(
				fmt.Sprintf("Order %v: shipped, ETA April 2nd", orderID),
			)
		},
	})

	a.Run()
}

import com.signalwire.sdk.agent.AgentBase;
import com.signalwire.sdk.swaig.FunctionResult;

import java.util.List;
import java.util.Map;

public class SupportAgent {
    public static void main(String[] args) throws Exception {
        var agent = AgentBase.builder()
                .name("Support Agent")
                .route("/support")
                .build();

        agent.promptAddSection("Instructions",
                "You are a customer support agent. "
              + "Greet the caller and resolve their issue.");

        agent.addLanguage("English", "en-US", "rime.spore:mistv2");

        agent.defineTool(
                "check_order",
                "Check the status of a customer order",
                Map.of("type", "object",
                       "properties", Map.of(
                           "order_id", Map.of(
                               "type", "string",
                               "description", "The order ID to look up")),
                       "required", List.of("order_id")),
                (toolArgs, rawData) -> {
                    var orderId = toolArgs.get("order_id");
                    return new FunctionResult(
                        "Order " + orderId + ": shipped, ETA April 2nd");
                }
        );

        agent.run();
    }
}

# frozen_string_literal: true

require 'signalwire'

agent = SignalWire::AgentBase.new(name: 'Support Agent', route: '/support')

agent.prompt_add_section('Instructions',
  'You are a customer support agent. Greet the caller and resolve their issue.')

agent.add_language(name: 'English', code: 'en-US', voice: 'rime.spore:mistv2')

agent.define_tool(
  name:        'check_order',
  description: 'Check the status of a customer order',
  parameters:  {
    'order_id' => { 'type' => 'string', 'description' => 'The order ID to look up' }
  }
) do |args, _raw|
  SignalWire::Swaig::FunctionResult.new(
    "Order #{args['order_id']}: shipped, ETA April 2nd"
  )
end

agent.run

<?php
require 'vendor/autoload.php';

use SignalWire\Agent\AgentBase;
use SignalWire\SWAIG\FunctionResult;

$agent = new AgentBase(['name' => 'Support Agent', 'route' => '/support']);

$agent->promptAddSection('Instructions',
    'You are a customer support agent. Greet the caller and resolve their issue.');

$agent->addLanguage('English', 'en-US', 'rime.spore:mistv2');

$agent->defineTool(
    name: 'check_order',
    description: 'Check the status of a customer order',
    parameters: [
        'order_id' => ['type' => 'string', 'description' => 'The order ID to look up'],
    ],
    handler: function (array $args): FunctionResult {
        return new FunctionResult("Order {$args['order_id']}: shipped, ETA April 2nd");
    }
);

$agent->run();

#!/usr/bin/env perl
use strict;
use warnings;
use lib 'lib';
use SignalWire::Agent::AgentBase;
use SignalWire::SWAIG::FunctionResult;

my $agent = SignalWire::Agent::AgentBase->new(
    name  => 'Support Agent',
    route => '/support',
);

$agent->prompt_add_section('Instructions',
    'You are a customer support agent. Greet the caller and resolve their issue.');

$agent->add_language(name => 'English', code => 'en-US', voice => 'rime.spore:mistv2');

$agent->define_tool(
    name        => 'check_order',
    description => 'Check the status of a customer order',
    parameters  => {
        order_id => { type => 'string', description => 'The order ID to look up' },
    },
    handler => sub {
        my ($args, $raw) = @_;
        return SignalWire::SWAIG::FunctionResult->new(
            response => "Order $args->{order_id}: shipped, ETA April 2nd"
        );
    },
);

$agent->run;

#include <signalwire/agent/agent_base.hpp>

using namespace signalwire;
using json = nlohmann::json;

class SupportAgent : public agent::AgentBase {
public:
    SupportAgent() : AgentBase("Support Agent", "/support") {
        prompt_add_section("Instructions",
            "You are a customer support agent. "
            "Greet the caller and resolve their issue.");

        add_language({"English", "en-US", "rime.spore:mistv2"});

        define_tool({
            .name = "check_order",
            .description = "Check the status of a customer order",
            .parameters = {
                {"order_id", {{"type", "string"},
                              {"description", "The order ID to look up"}}}
            },
            .handler = [](const json& args, const json&) {
                auto order_id = args.value("order_id", "unknown");
                return swaig::FunctionResult(
                    "Order " + order_id + ": shipped, ETA April 2nd");
            }
        });
    }
};

int main() {
    SupportAgent().run();
}

using SignalWire.Agent;
using SignalWire.SWAIG;

var agent = new AgentBase(new AgentOptions { Name = "Support Agent", Route = "/support" });

agent.PromptAddSection("Instructions",
    "You are a customer support agent. Greet the caller and resolve their issue.");

agent.AddLanguage("English", "en-US", "rime.spore:mistv2");

agent.DefineTool("check_order", "Check the status of a customer order",
    new { type = "object", properties = new {
        order_id = new { type = "string", description = "The order ID to look up" }
    }, required = new[] { "order_id" } },
    (args, rawData) =>
    {
        var orderId = args.TryGetValue("order_id", out var id) ? id : "unknown";
        return new FunctionResult($"Order {orderId}: shipped, ETA April 2nd");
    });

agent.Run();

use signalwire::agent::AgentBase;
use signalwire::swaig::FunctionResult;
use serde_json::json;

fn main() {
    let mut agent = AgentBase::builder()
        .name("Support Agent")
        .route("/support")
        .build();

    agent
        .prompt_add_section("Instructions",
            "You are a customer support agent. Greet the caller and resolve their issue.", &[])
        .add_language("English", "en-US", "rime.spore:mistv2");

    agent.define_tool(
        "check_order",
        "Check the status of a customer order",
        json!({"type": "object", "properties": {
            "order_id": {"type": "string", "description": "The order ID to look up"}
        }, "required": ["order_id"]}),
        Box::new(|args, _raw| {
            let order_id = args.get("order_id").and_then(|v| v.as_str()).unwrap_or("unknown");
            FunctionResult::with_response(&format!("Order {order_id}: shipped, ETA April 2nd"))
        }),
    );

    agent.run();
}

What Changes When You Add SignalWire

DIY Telephony Stack

Asterisk dialplan, Perl middleware, Redis queues
SIP trunk configuration and codec debugging
Carrier negotiations and regulatory forms
Custom WebSocket-to-SIP bridge code
Separate vendors for numbers, trunking, and orchestration
Weeks of integration before your first call

SignalWire + Your AI

pip install, define your agent, assign a phone number
SIP, PSTN, and WebRTC handled natively
Phone numbers in one click, no forms
WebSocket, YAML, or SIP URI connection
One platform built by the FreeSWITCH team
Under 10 minutes to first production call

What You Keep, What SignalWire Handles

You Keep	SignalWire Handles
Your LLM (OpenAI, Anthropic, self-hosted)	SIP/RTP/PSTN connectivity
Your STT provider (Deepgram, Whisper, others)	Phone number provisioning
Your TTS provider (ElevenLabs, PlayHT, others)	Codec negotiation and transcoding
Your conversation logic and tools	Call transfers, hold, conferencing
Your deployment infrastructure	Call recording and compliance
Your cost optimization work	Carrier-grade reliability and scale

Under 10 Minutes to First Call

1

Install the SDK

pip install signalwire-agents. No trunk configuration, no carrier negotiations.

2

Define your agent

A Python class or YAML document. Your prompts, your tools, your conversation logic.

3

Get a phone number

One click for US numbers in the SignalWire dashboard. No regulatory forms.

4

Call it

Your AI answers a real phone call. SIP, PSTN, or WebRTC, all handled natively.

SignalWire was founded by the creators of FreeSWITCH, the open-source telecom stack that carriers and enterprises have relied on for two decades. This is the telephony team giving your AI a production-grade phone system.

FAQ

Does SignalWire replace my AI stack?

No. SignalWire has no opinion on which LLM, STT, or TTS you use. Your AI is the brain. SignalWire is the nervous system connecting it to the phone network.

What protocols does SignalWire support?

SIP, PSTN, and WebRTC natively. Your AI connects via WebSocket, Python SDK, or a declarative YAML document. SignalWire handles protocol translation.

How does codec negotiation work?

SignalWire transcodes between G.711 (PSTN), Opus (WebRTC), and other codecs automatically. No manual codec configuration required.

What call control features are included?

Blind and warm transfers, hold, conferencing, recording, IVR fallback, DTMF handling, and call disposition tracking. All available through the SDK or YAML.

What does it cost?

Telephony at carrier rates with no per-agent fees or orchestration surcharges. The native AI option is $0.16/min covering STT, LLM orchestration, and TTS. Transport billed separately at carrier rates. One invoice.

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Connect your voice AI to the phone network in under 10 minutes.

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