SignalWire.Sdk 1.1.2

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SignalWire SDK for .NET

Build AI voice agents, control live calls over WebSocket, and manage every SignalWire resource over REST -- all from one package.

<p align="center"> <a href="https://developer.signalwire.com/sdks/agents-sdk" target="_blank">Documentation</a> · <a href="https://github.com/signalwire/signalwire-docs/issues/new/choose" target="_blank">Report an Issue</a> · <a href="https://www.nuget.org/packages/SignalWire.Sdk" target="_blank">NuGet</a> </p>

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What's in this SDK

dotnet add package SignalWire.Sdk

AI Agents

Each agent is a self-contained microservice that generates SWML (SignalWire Markup Language) and handles SWAIG (SignalWire AI Gateway) tool calls. The SignalWire platform runs the entire AI pipeline (STT, LLM, TTS) -- your agent just defines the behavior.

using SignalWire.Agent;
using SignalWire.SWAIG;

var agent = new AgentBase(new AgentOptions { Name = "my-agent", Route = "/agent" });

agent.AddLanguage("English", "en-US", "inworld.Mark");
agent.PromptAddSection("Role", "You are a helpful assistant.");

agent.DefineTool("get_time", "Get the current time", new { },
    (args, rawData) => new FunctionResult($"The time is {DateTime.Now:HH:mm:ss}"));

agent.Run();

Agent Features

• Prompt Object Model (POM) -- structured prompt composition via PromptAddSection()
• SWAIG tools -- define functions with DefineTool() that the AI calls mid-conversation
• Skills system -- add capabilities with one-liners: agent.AddSkill("datetime")
• Contexts and steps -- structured multi-step workflows with navigation control
• DataMap tools -- tools that execute on SignalWire's servers without your own webhook
• Dynamic configuration -- per-request agent customization for multi-tenant deployments
• Call flow control -- pre-answer, post-answer, and post-AI verb insertion
• Prefab agents -- ready-to-use archetypes (InfoGatherer, Survey, FAQ, Receptionist, Concierge)
• Multi-agent hosting -- serve multiple agents on a single server with AgentServer
• SIP routing -- route SIP calls to agents based on usernames
• Session state -- persistent conversation state with global data and post-prompt summaries
• Security -- auto-generated basic auth, function-specific HMAC tokens
• Serverless -- Azure Functions, AWS Lambda, and auto-detection adapters

RELAY Client

Real-time call control and messaging over WebSocket. The RELAY client connects to SignalWire via the Blade protocol and gives you async control over live phone calls and SMS/MMS.

using SignalWire.Relay;

var client = new RelayClient(new RelayOptions
{
    Project = "your-project-id",
    Token = "your-token",
    Host = "example.signalwire.com",
    Contexts = ["default"],
});

client.OnCall(async call =>
{
    await call.Answer();
    var action = await call.Play(new[] { new TtsMedia("Welcome to SignalWire!") });
    await action.Wait();
    await call.Hangup();
});

await client.Run();

• 57+ calling methods (play, record, collect, detect, tap, stream, AI, conferencing, and more)
• SMS/MMS messaging with delivery tracking
• Action objects with Wait(), Stop(), Pause(), Resume()
• Auto-reconnect with exponential backoff

See the RELAY documentation for the full guide, API reference, and examples.

REST Client

Synchronous REST client for managing SignalWire resources and controlling calls over HTTP.

using SignalWire.REST;

var client = new RestClient("project-id", "token", "example.signalwire.com");

client.Fabric.AiAgents.Create(new { name = "Support Bot" });
client.Calling.Play(callId, new { play = new[] { new { type = "tts", text = "Hello!" } } });
client.PhoneNumbers.List(new { area_code = "512" });
client.Datasphere.Documents.Search(new { query_string = "billing policy" });

• 21 namespaced API surfaces: Fabric, Calling, Video, Datasphere, Compat, and more
• HttpClient with connection pooling
• Dictionary returns -- raw data, no wrapper objects

See the REST documentation for the full guide, API reference, and examples.

Installation

dotnet add package SignalWire.Sdk

Requires .NET 8.0+. Works with C#, F#, VB.NET, and any CLR language.

Environment Variables

Testing

dotnet test

License

MIT -- see LICENSE for details.