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

# Overview

Nodes are the building blocks of a flow, and you wire them together on the canvas to make something useful.

## Connecting nodes to your apps

Any node that talks to an outside app needs a credential. Open the node's **Credential** field and pick one of your [connected apps](/connected-apps/overview). If you have not connected that app yet, the field shows **No credentials available** with an **Add** link, so you can connect it without leaving the builder.

Some nodes connect to QX itself instead of an outside app, so a flow can run one of your [agents](/agents/overview) or call another flow.

If you are building in **Chat** mode, none of this is manual. The builder asks you to pick an account whenever a node needs one.

## Categories

<Columns cols={2}>
  <Card title="Triggers" icon="zap" href="/flows/nodes/triggers">
    Start a flow when something happens in one of your apps.
  </Card>

  <Card title="Workflow basics" icon="git-branch" href="/flows/nodes/workflow-basics">
    Inputs, outputs, branching, and running one flow inside another.
  </Card>

  <Card title="AI" icon="sparkles" href="/flows/nodes/ai">
    Ask a model, research the web, run your agents, and sort or extract data.
  </Card>

  <Card title="File operations" icon="file-text" href="/flows/nodes/file-operations">
    Read documents and spreadsheets, and export your results as files.
  </Card>

  <Card title="List and text operations" icon="list" href="/flows/nodes/list-and-text">
    Build, filter, and reshape lists, and put text together.
  </Card>

  <Card title="Web operations" icon="globe" href="/flows/nodes/web-operations">
    Search, scrape, and crawl the web.
  </Card>

  <Card title="Custom code" icon="code" href="/flows/nodes/custom-code">
    Run your own Python for anything no node covers.
  </Card>

  <Card title="Custom code trigger" icon="webhook" href="/flows/nodes/custom-code-trigger">
    Start a flow from events in any app in the catalog.
  </Card>

  <Card title="Integrations" icon="plug" href="/flows/nodes/integrations">
    Per-app nodes for Google, Microsoft, Salesforce, Slack, Notion, and more.
  </Card>
</Columns>