AgentCore

A .NET library for building voice and chat agents. The agent is a configuration document; the host is two calls.

1. Describe the agent

config/helper.yaml:

apiVersion: agentcore/v1
name: helper

agents:
  defaults:
    model: { ref: reply }
    instructions: |
      You are a helpful assistant. Answer plainly and briefly.
  items:
    - id: helper
      instructions: |
        Answer whatever the person asks.
      tools: []

policy:
  initial: talk
  stages:
    - id: talk
      agent: helper
      terminal: true

providers:
  llm:
    - { kind: openai, model: gpt-5.6-luna, as: reply }
  conversation: { kind: telnyx-relay }
  speech:
    stt: { kind: telnyx-relay }
    tts: { kind: telnyx-relay }

agents holds the instructions, policy holds the stages, providers binds the vendors. No C# changes to add a stage, a tool, or a model. config/example.yaml is the annotated tour of every key.

2. Wire up the host

using AgentCore.Hosting;

var builder = WebApplication.CreateBuilder(args);
builder.AddAgentCoreHost();

var app = builder.Build();
app.MapAgentCoreHost();
app.Run();

AddAgentCoreHost loads the document (config/example.yaml unless AgentCore__ConfigurationPath names another) and binds every vendor seam. MapAgentCoreHost serves the health check, the OpenAI-compatible Responses endpoint, the conversation socket, and the AG-UI endpoint. Every entry under entries: answers on POST /v1/{entry}/responses, on the conversation socket at /v1/{entry}/call, and on AG-UI at POST /agui/{entry}. An OpenAI SDK reaches one entry through its base URL alone: base_url = https://host/v1/phone. A document it cannot find is a startup failure, never a silent default.

Install

dotnet add package AgentCore.Hosting

AgentCore.Hosting brings the rest of the set with it.

3. Talk to it

Over the OpenAI-compatible endpoint (/v1/responses), the document above holds this conversation:

User: Hello

Assistant: How can I help you today!

The packages

Package	Holds
AgentCore.Domain	Pure domain records. Zero dependencies.
AgentCore.Application	Orchestration, configuration compilation, and every port interface.
AgentCore.Infrastructure	Outbound adapters: OpenAI, Zilliz, Telnyx call control, Postgres, B2, Git.
AgentCore.AspNetCore	Inbound adapters as Map* extensions: Telnyx Conversation Relay, Telnyx webhooks, Responses, AG-UI.
AgentCore.Hosting	The batteries-included host: every vendor seam bound and every route mapped, in two calls.

They share one version and ship as a set. Mixing versions across them is unsupported.

Licence

MIT