Your first agent

Turn a provider model into a reusable agent with a clear identity, instructions, and a bounded model loop.

Before you start

Complete Install and setup first. You should already have @anvia/core, a provider package, and a working API key.

Build the agent

Create the provider model, then pass it to AgentBuilder.

import { AgentBuilder } from '@anvia/core'
import { OpenAIClient } from '@anvia/openai'

const client = new OpenAIClient({
  apiKey: process.env.OPENAI_API_KEY,
})

const model = client.completionModel('gpt-5')

const agent = new AgentBuilder('support', model)
  .instructions('Answer support questions clearly and ask for missing details.')
  .defaultMaxTurns(4)
  .build()

The agent setup has four parts:

Part	Purpose
support	Gives the agent a stable identity.
model	Supplies the provider-backed completion model.
instructions(...)	Defines the agent's reusable behavior.
defaultMaxTurns(4)	Bounds the model and tool loop for each run.

Send a prompt

Create a run with prompt(), then execute it with send().

const response = await agent
  .prompt('What information do you need to investigate a failed checkout?')
  .send()

console.log(response.output)

The exact response can vary, but it should follow the support instructions and ask for any details it needs.

Agent or direct completion?

Use a direct completion when	Use an agent when
The task is a single model call.	Behavior should be reusable across requests.
Your application owns all orchestration.	The task needs instructions, tools, memory, or multiple turns.

Your agent is now ready for capabilities such as tools, memory, and streaming.