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

# The Drawing Index

> Understand the structured knowledge graph that Bedrock builds from your construction drawings.

## What is the Drawing Index?

The Drawing Index is a structured knowledge graph of your construction drawing set. When you upload a PDF, Bedrock segments every page into sheets and blocks, classifies content, and extracts text for search. Use the Vision API to detect symbols, generate revision overlays, and analyze changes. All results are stored as queryable entities with typed relationships.

## The search engine analogy

Enterprise search tools like Elasticsearch take unstructured documents, parse them, and build an index so you can query instantly. Bedrock does the same thing for construction drawings, the densest unstructured documents in the built world, making them incredibly difficult for LLM and AI agents to reason through.

| Search engine        | Bedrock                                        |
| -------------------- | ---------------------------------------------- |
| Ingest documents     | Upload drawing PDFs                            |
| Tokenize and parse   | Segment sheets into blocks, detect features    |
| Build inverted index | Build knowledge graph with relations and grids |
| Query with filters   | Query any entity by type, label, grid location |

The result: instead of flipping through hundreds of PDF pages, you query the Drawing Index and get structured results that can be fed into your automation workflows or agentic systems.

## How it works

<Steps>
  <Step title="Upload">
    Submit construction drawing PDFs via the CMS API. Any size, any discipline.
  </Step>

  <Step title="Parse">
    Bedrock's vision pipeline segments each page into sheets and blocks, classifies block types (plan view, schedule, legend, title block), and extracts text for indexing. Use the Vision API to run symbol detection, overlay generation, and change analysis on demand.
  </Step>

  <Step title="Query">
    Access the structured Drawing Index through the REST API for your application or the MCP Server for AI agents (Claude, ChatGPT, Microsoft Copilot).
  </Step>
</Steps>

## Entity hierarchy

The Drawing Index organizes construction documents into a hierarchy: **Organization** → **Project** → **File** → **Drawing** → **Sheet** → **Block** → **Feature**. Every query traverses this tree.

```mermaid theme={null}
graph TD
  O["Organization"]:::meta
  P["Project"]:::meta
  FL["File (PDF upload)"]:::meta

  O --> P
  P --> FL
  FL --> D

  D["Drawing (processed)"]:::drawing

  D --> S1["Sheet: A-101 First Floor Plan"]:::sheet
  D --> S2["Sheet: A-102 Second Floor Plan"]:::sheet
  D --> S3["Sheet: A-501 Details"]:::sheet

  S1 --> B1["Plan view"]:::block
  S1 --> B2["Door Schedule"]:::block
  S1 --> B3["Legend"]:::block
  S1 --> B4["Title Block"]:::block

  B1 --> F1["room '201'"]:::feature
  B1 --> F2["door '104'"]:::feature
  B1 --> F3["duplex_receptacle"]:::feature

  classDef meta fill:#f5f5f5,color:#555,stroke:#bbb
  classDef drawing fill:#009689,color:#fff,stroke:#007a6f
  classDef sheet fill:#00BBA7,color:#fff,stroke:#009689
  classDef block fill:#e0f2f1,color:#333,stroke:#009689
  classDef feature fill:#f5f5f5,color:#555,stroke:#bbb
```

**Drawings** contain **Sheets** (pages). Each Sheet contains **Blocks** (plan views, schedules, legends). Each Block contains **Features** (rooms, doors, symbols). [**Relations**](/guides/concepts/relations) connect entities across the graph — a door to its schedule row, a symbol to its legend definition. A shared [**Grid**](/guides/concepts/grid-system) coordinate system aligns everything across disciplines.

## A simple query

To see the power of the Drawing Index, consider this question: "How many duplex receptacles are on sheet E-201?"

Without the Drawing Index, someone has to open the PDF, navigate to E-201, and count symbols by hand. With the Drawing Index:

```json theme={null}
// query_feature({ sheet_number: "E-201", type: "duplex_receptacle" })
{
  "count": 17,
  "items": [
    { "type": "duplex_receptacle", "label": null, "parent": "Room 201", "grid": "A-2" },
    { "type": "duplex_receptacle", "label": null, "parent": "Room 201", "grid": "A-3" },
    { "type": "duplex_receptacle", "label": null, "parent": "Room 202", "grid": "B-2" }
  ]
}
```

Every feature carries its parent context (which room it is in) and grid location (where it sits on the building coordinate system).

## Deep dives

<CardGroup cols={2}>
  <Card title="Relations" href="/guides/concepts/relations">
    Cross-references and connections: the edges of the knowledge graph.
  </Card>

  <Card title="Grid System" href="/guides/concepts/grid-system">
    The universal coordinate system for cross-discipline coordination.
  </Card>
</CardGroup>