> ## 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.

# Grid Intersection Query

> Find all features across disciplines at a grid location.

## User Prompt

> "What's at grid B-3?"

## Tool Call Sequence

<Steps>
  <Step title="Query features at the grid intersection">
    **Call:** `Query`

    ```json theme={null}
    {
      "entity": "feature",
      "project_id": "proj_oak",
      "grid_intersection": "B-3",
      "include": ["parent_chain"]
    }
    ```

    **Response:**

    ```json theme={null}
    {
      "count": 9,
      "items": [
        {
          "id": "ftr_rm102",
          "type": "room",
          "label": "102",
          "bounds": { "type": "polygon", "points": [[280, 400], [450, 400], [450, 620], [280, 620]] },
          "confidence": 0.93,
          "metadata": { "area_sf": 340 },
          "parent_chain": [
            { "entity_type": "block", "id": "blk_a101_plan", "type": "Plan", "identifier": "1" },
            { "entity_type": "sheet", "id": "sh_a101", "sheet_number": "A-101", "discipline": "A" },
            { "entity_type": "drawing", "id": "dr_arch_b", "name": "Arch Set Rev B" }
          ],
          "relations": []
        },
        {
          "id": "ftr_beam_01",
          "type": "beam",
          "label": "W16x40",
          "bounds": { "type": "bbox", "xmin": 300, "ymin": 480, "xmax": 420, "ymax": 490 },
          "confidence": 0.91,
          "metadata": { "designation": "W16x40", "elevation_top": "11'-2\"", "elevation_bottom": "9'-10\"" },
          "parent_chain": [
            { "entity_type": "block", "id": "blk_s201_plan", "type": "Plan", "identifier": "1" },
            { "entity_type": "sheet", "id": "sh_s201", "sheet_number": "S-201", "discipline": "S" },
            { "entity_type": "drawing", "id": "dr_struct", "name": "Structural Set" }
          ],
          "relations": []
        },
        {
          "id": "ftr_duct_01",
          "type": "duct",
          "label": "24x12 SA",
          "bounds": { "type": "polyline", "points": [[280, 485], [340, 485], [420, 485]] },
          "confidence": 0.88,
          "metadata": { "size": "24x12", "system": "SA", "elevation_cl": "11'-0\"" },
          "parent_chain": [
            { "entity_type": "block", "id": "blk_m201_plan", "type": "Plan", "identifier": "1" },
            { "entity_type": "sheet", "id": "sh_m201", "sheet_number": "M-201", "discipline": "M" },
            { "entity_type": "drawing", "id": "dr_mech", "name": "Mechanical Set" }
          ],
          "relations": []
        },
        {
          "id": "ftr_sprk_01",
          "type": "sprinkler_head",
          "label": null,
          "confidence": 0.90,
          "parent_chain": [
            { "entity_type": "block", "id": "blk_fp201_plan", "type": "Plan", "identifier": "1" },
            { "entity_type": "sheet", "id": "sh_fp201", "sheet_number": "FP-201", "discipline": "FP" },
            { "entity_type": "drawing", "id": "dr_fp", "name": "Fire Protection Set" }
          ],
          "relations": []
        }
      ]
    }
    ```

    **What the agent learns:** 9 features from 4 disciplines overlap at grid B-3. The `parent_chain` on each feature tells the agent which sheet and discipline it came from, enabling cross-discipline grouping without extra queries.
  </Step>
</Steps>

## Agent Response

> Here's what's at **grid B-3** across all disciplines:
>
> **Architectural** (A-101): Room 102 (340 SF)
>
> **Structural** (S-201): W16x40 beam (top: 11'-2", bottom: 9'-10")
>
> **Mechanical** (M-201): 24x12 supply air duct (centerline: 11'-0")
>
> **Fire Protection** (FP-201): Sprinkler head
>
> Note: The SA duct bottom (10'-6") overlaps with the beam top (11'-2") -- this may be a coordination issue. Want me to investigate further?

## Summary

| Metric        | Value                                                                                                                                                                                                         |
| ------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Tool calls    | **1**                                                                                                                                                                                                         |
| Tools used    | `Query`                                                                                                                                                                                                       |
| Key technique | The `grid_intersection` filter handles all the spatial math. The backend resolves grid line positions across disciplines. `parent_chain` provides discipline context so the agent can group results by trade. |