> ## Documentation Index
> Fetch the complete documentation index at: https://docs.agentium.in/llms.txt
> Use this file to discover all available pages before exploring further.

# Build with Agentium

> Build, test, and run agent applications with a composable TypeScript SDK.

Agentium connects models to your application's tools, data, and workflows. Start with a single agent, then add the packages you need for reusable harnesses, APIs, background jobs, browsers, voice, or devices.

**New to Agentium?** Get a working project first. You can choose your application's architecture after you have seen a run succeed.

<Columns cols={2}>
  <Card title="Create a new project" icon="terminal" href="/learn/create-project">Scaffold a TypeScript app, configure a model, and get your first response.</Card>
  <Card title="Add to an existing app" icon="code" href="/quickstart">Install core and run an Agent in your own project.</Card>
</Columns>

Prefer to explore without an API key? Try the [controlled-workflow demo](/examples/harness-workflow): approve or deny a simulated refund using `@agentium/harness`.

## Learn the essentials

<Steps>
  <Step title="Understand the pieces">Learn what belongs to [core and the optional packages](/introduction), then [choose Agent, Harness, Team, or Workflow](/learn/choose-an-approach).</Step>
  <Step title="Build something useful">Follow the [support assistant tutorial](/learn/support-assistant): tool calls → conversation state → retrieval → approval → streaming → HTTP. Each checkpoint is a complete program.</Step>
  <Step title="Make it dependable">Add a [repeatable quality gate](/examples/quality-gate), inspect traces, and follow the [shipping path](/ship/overview) for your deployment.</Step>
</Steps>

## Find your application path

<Columns cols={2}>
  <Card title="Assistants and APIs" icon="comments" href="/build/overview#assistants-and-apis">Answer from your data, call tools, return structured output, and serve requests.</Card>
  <Card title="Harnesses and automation" icon="layer-group" href="/build/overview#harnesses-and-automation">Compose abilities and controls around agents, teams, or workflows.</Card>
  <Card title="Voice and phone applications" icon="microphone" href="/build/overview#voice-and-phone-applications">Choose speech, media transport, and call control as separate parts of one application.</Card>
  <Card title="Background work" icon="clock" href="/build/overview#background-and-recoverable-work">Deliver queued jobs, schedule work, and choose a recovery contract.</Card>
  <Card title="Browsers and workspaces" icon="desktop" href="/build/overview#browsers-and-execution-workspaces">Operate web interfaces and configure local or remote execution environments.</Card>
  <Card title="Device applications" icon="microchip" href="/build/overview#device-applications">Connect hardware toolkits, local models, runtime monitoring, and cloud synchronization.</Card>
</Columns>

## Add only what your application needs

Start with `@agentium/core`. Add the standalone `@agentium/harness` for reusable execution capabilities, transport for APIs, queue for background delivery, browser or edge for environment access, and eval and observability for feedback. CLI scaffolding and admin configuration management round out the ten packages.

Voice, telephony, memory, retrieval, toolkits, and durable primitives belong to core. Find their boundaries in the [package guide](/introduction), named adapters in [Integrations](/integrations/overview), and exact contracts in [Reference](/reference/overview).


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