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

# How Casa Conect is built

> The applications and components that make up Casa Conect, and the principles that hold them together. Written for IT and technical reviewers.

This section describes how Casa Conect is put together, at the level a technical reviewer needs to assess it. For the security posture specifically, start with the [Security overview](/security/overview).

<Note>
  This page describes our security practices at the level of a help page. We share detailed security documentation, architecture reviews and completed questionnaires with customers on request. Write to [support@casaconect.ai](mailto:support@casaconect.ai).
</Note>

## The shape of the system

Casa Conect is a single codebase containing a small number of deployable **applications** and a set of internal **components** that they share. Everything is written in TypeScript in strict mode, and every piece of external data is validated against a schema at the boundary.

```
Browser · Microsoft Word · Email · Share-link recipients
        │
        ▼
   Edge: content delivery network + web application firewall
        │
  ┌─────┴──────────────┬──────────────────┬─────────────────┐
  ▼                    ▼                  ▼                 ▼
Dashboard            API               Collaboration     Word add-in
(web app)      (typed API)             server (live      (task pane)
                       │               editing)
        ┌──────────────┼───────────────────────┐
        ▼              ▼                       ▼
   Background       Rendering             Data layer
   jobs             service               database · file storage · cache
   (agent sessions, (Word → PDF)
   indexing, sync)
```

| Application              | Role                                                                                            |
| :----------------------- | :---------------------------------------------------------------------------------------------- |
| **Dashboard**            | The signed-in web application, and the public pages behind share links                          |
| **API**                  | The single backend. Every client talks to it, and all authorization happens here.               |
| **Collaboration server** | Holds the live state of documents being edited, and synchronizes editors in real time           |
| **Rendering service**    | Converts Word documents to PDF. Internal only, with no public surface.                          |
| **Background jobs**      | Durable and scheduled work: agent sessions, document indexing, drive sync, workflows, reminders |
| **Word add-in**          | The task pane inside Microsoft Word                                                             |
| **Website**              | The public marketing site. It has no connection to customer data.                               |

The shared components are described in [Components](/reference/components), and four end-to-end journeys through the system in [Data flows](/reference/data-flows).

## Design principles

<AccordionGroup>
  <Accordion title="Authorization lives in one place" icon="key-round">
    Access control is enforced in the API, keyed to an identity that is verified on every request. Routers orchestrate; business rules live in an application layer beneath them; the database reinforces tenancy. See [Access control](/security/access-control).
  </Accordion>

  <Accordion title="Narrow surfaces" icon="scan">
    Components expose small, specific entry points rather than general-purpose clients. There is one gateway to file storage, one function that queues a document for indexing, and exactly one code path that writes to a Word document from the add-in.
  </Accordion>

  <Accordion title="One implementation for each concern" icon="git-merge">
    Every route by which a document arrives passes through the same pipeline. Every version, from any surface, lands in one history. There is one agent for every situation, configured per request, rather than a family of agents that could drift apart.
  </Accordion>

  <Accordion title="Fail closed where it matters" icon="shield">
    Security decisions fail closed: an incomplete malware scan, a failed safety review, a PIN check that cannot run. Protective conveniences, such as a general rate limiter that the firewall also enforces, fail open with a log entry.
  </Accordion>

  <Accordion title="Honest degradation" icon="message-square-warning">
    When something cannot be done exactly, the user is told. A font that cannot be matched is named. A Word construction that cannot be represented produces a notice. A document that is not yet indexed is reported as such.
  </Accordion>

  <Accordion title="Bounded work" icon="gauge">
    Every unit of background work has a time limit, a retry policy and a concurrency cap. Agent turns have step budgets. Queues apply backpressure before anything falls over.
  </Accordion>

  <Accordion title="Infrastructure as code" icon="file-code">
    The cloud environment is defined in code, with state and runs managed remotely and cloud access through short-lived federated credentials. There are no static keys. Production changes are applied manually after review, and database migrations are applied by the deployment pipeline, never from a developer's machine.
  </Accordion>
</AccordionGroup>

## Foundations

| Layer           | Built on                                                                                     |
| :-------------- | :------------------------------------------------------------------------------------------- |
| Language        | TypeScript, strict mode, throughout                                                          |
| Web application | React, server-rendered                                                                       |
| Editor          | The open-source ProseMirror ecosystem, with tracked changes and page layout written in-house |
| Documents       | An in-house Office Open XML engine; LibreOffice for PDF rendering, self-hosted               |
| Data            | PostgreSQL, with vector search built in                                                      |
| Identity        | WorkOS AuthKit                                                                               |
| Cloud           | Amazon Web Services, in the European Union                                                   |

## Next

<CardGroup cols={2}>
  <Card title="Components" icon="package" href="/reference/components">
    What each part of the platform is responsible for.
  </Card>

  <Card title="Data flows" icon="route" href="/reference/data-flows">
    Four journeys through the system, end to end.
  </Card>
</CardGroup>