Months of Plumbing or Days of Product | SignalWire
Build vs. Buy for Voice AI
Months of Plumbing or Days of Product
Production voice AI on legacy platforms requires WebSocket servers, codec handling, barge-in state machines, and five vendor integrations. The same agent ships in days on SignalWire.
You build and host a WebSocket server that converts mu-law 8kHz to PCM 16kHz, manages connection lifecycle, and handles heartbeat timeouts. Two to three weeks of senior engineering time.
STT, LLM, and TTS integration
Three separate provider APIs, each with streaming protocols, error handling, and retry logic. Each integration takes one to two weeks. Format mismatches between providers fail silently.
Barge-in state machine
Voice activity detection triggers a 5ms window to flush the TTS buffer, cancel the LLM stream, and reset state. Two to three weeks to get right. Breaks differently under load.
Session state and error handling
Redis or database integration for conversation context, authentication state, and transfer history. Cross-provider failure detection where each vendor logs their own slice and nobody sees the full picture.
Build a Voice AI Agent
fromsignalwire_agentsimportAgentBasefromsignalwire_agents.core.function_resultimportSwaigFunctionResultclassSupportAgent(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")defcheck_order(self,order_id:str):"""Check the status of a customer order. Args: order_id: The order ID to look up """returnSwaigFunctionResult(f"Order {order_id}: shipped, ETA April 2nd")agent=SupportAgent()agent.run()
import{AgentBase,FunctionResult}from'@signalwire/sdk';constagent=newAgentBase({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)=>{returnnewFunctionResult(`Order ${args.order_id}: shipped, ETA April 2nd`);},});agent.run();
packagemainimport("fmt""github.com/signalwire/signalwire-go/pkg/agent""github.com/signalwire/signalwire-go/pkg/swaig")funcmain(){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(argsmap[string]any,rawDatamap[string]any)*swaig.FunctionResult{orderID:=args["order_id"]returnswaig.NewFunctionResult(fmt.Sprintf("Order %v: shipped, ETA April 2nd",orderID),)},})a.Run()}
importcom.signalwire.sdk.agent.AgentBase;importcom.signalwire.sdk.swaig.FunctionResult;importjava.util.List;importjava.util.Map;publicclassSupportAgent{publicstaticvoidmain(String[]args)throwsException{varagent=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)->{varorderId=toolArgs.get("order_id");returnnewFunctionResult("Order "+orderId+": shipped, ETA April 2nd");});agent.run();}}
# frozen_string_literal: truerequire'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")endagent.run
<?phprequire'vendor/autoload.php';useSignalWire\Agent\AgentBase;useSignalWire\SWAIG\FunctionResult;$agent=newAgentBase(['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{returnnewFunctionResult("Order {$args['order_id']}: shipped, ETA April 2nd");});$agent->run();
#!/usr/bin/env perlusestrict;usewarnings;uselib'lib';useSignalWire::Agent::AgentBase;useSignalWire::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)=@_;returnSignalWire::SWAIG::FunctionResult->new(response=>"Order $args->{order_id}: shipped, ETA April 2nd");},);$agent->run;
#include<signalwire/agent/agent_base.hpp>usingnamespacesignalwire;usingjson=nlohmann::json;classSupportAgent:publicagent::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=[](constjson&args,constjson&){autoorder_id=args.value("order_id","unknown");returnswaig::FunctionResult("Order "+order_id+": shipped, ETA April 2nd");}});}};intmain(){SupportAgent().run();}
usingSignalWire.Agent;usingSignalWire.SWAIG;varagent=newAgentBase(newAgentOptions{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)=>{varorderId=args.TryGetValue("order_id",outvarid)?id:"unknown";returnnewFunctionResult($"Order {orderId}: shipped, ETA April 2nd");});agent.Run();
usesignalwire::agent::AgentBase;usesignalwire::swaig::FunctionResult;useserde_json::json;fnmain(){letmutagent=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|{letorder_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 you build vs. what the platform handles
Legacy CPaaS Approach
You build and host a WebSocket server
You handle mu-law to PCM codec conversion
You integrate STT, TTS, and LLM providers separately
You build a barge-in state machine with 5ms timing
You manage session state in Redis or a database
You correlate error logs across five vendors
SignalWire
No WebSocket server needed; AI runs inside the media engine
Codec conversion handled internally
STT, TTS, and LLM orchestration built into the platform
Native barge-in in the media engine
Session variables and conversation context travel with the call
Single-stack error taxonomy with structured event streams
Timeline comparison
Component
Legacy CPaaS
SignalWire
WebSocket + codec handling
2-3 weeks
Not needed
STT integration
1-2 weeks
Built in
LLM integration
1-2 weeks
Built in
TTS integration
1-2 weeks
Built in
Barge-in handling
2-3 weeks
Built in
State management
2-3 weeks
Built in
Error handling across providers
1-2 weeks
Built in
Scaling and load balancing
2-4 weeks
Built in
Total
3-6 months
Days
From zero to production
1
Write a YAML document or Python class
Define your agent's prompt, tools, and conversation flow. No WebSocket server, no codec handling, no barge-in state machine.
2
Point a phone number at it
Assign a number to your agent. Inbound calls route directly to the AI inside the media engine.
3
Test with real calls
Call the number. Audio, STT, TTS, and tool calling work end-to-end on the first attempt.
4
Ship to production
Same platform, same behavior at scale. No integration surprises when load increases.
The YAML-based agent definition supports multi-step conversations, scoped tool access per step, warm transfers with full context, and a data layer the AI model never sees. Production capabilities without production plumbing.
FAQ
Can I use my own LLM, STT, or TTS provider?
Yes. Bring your own providers or use the integrated defaults. The platform handles codec conversion, streaming, and buffer management regardless of which providers you choose.
What if I need custom logic beyond YAML?
The Python SDK gives you full programmatic control. Define tools as Python functions, add custom business logic, and deploy as a standard web service.
How does SignalWire handle scaling?
The platform scales resources dynamically. No WebSocket connection pool management, no geographic distribution engineering, no load balancer configuration.
Who built this platform?
The team that wrote FreeSWITCH, the open-source telephony engine processing trillions of minutes across the industry. Production telephony is the foundation.
Trusted by 2,000+ companies
Ship this week, not next quarter.
Same AI capabilities. Same production requirements. Months fewer. Built by the FreeSWITCH team.