> For the complete documentation index, see [llms.txt](https://guardian.hedera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guardian.hedera.com/developer-tools-and-resources/api-reference/policy-grid-actions/list-grids.md).

# List Grids

**`GET /policies/{policyId}/grids`**

Returns every `interfaceDocumentsSourceBlock` that the caller's role can reach in the policy, together with its filter and column schemas. Use this to discover available grids without reading the internal policy block tree.

***

## Authentication

Requires a valid Guardian JWT bearer token. The caller must hold at least one of:

* `POLICIES_POLICY_EXECUTE`
* `POLICIES_POLICY_MANAGE`

***

## Request

### Path Parameters

| Parameter  | Type   | Required | Description                            |
| ---------- | ------ | -------- | -------------------------------------- |
| `policyId` | string | Yes      | MongoDB ObjectId of the running policy |

***

## Response

### Success Response

**Status:** `200 OK`

```json
[
  {
    "gridId": "installer_documents_grid",
    "title": "Installer Activity Reports",
    "description": "Documents submitted by installers",
    "filterSchema": [
      {
        "filterId": "date_filter",
        "title": "Date",
        "type": "datepicker",
        "field": "document.credentialSubject.0.reportingPeriod",
        "operators": ["eq"]
      }
    ],
    "columnSchema": [
      {
        "name": "status",
        "title": "Status",
        "type": "text",
        "bindActions": ["approve_action", "reject_action"]
      }
    ]
  }
]
```

| Field                        | Type   | Description                                                                         |
| ---------------------------- | ------ | ----------------------------------------------------------------------------------- |
| `gridId`                     | string | Stable grid identifier — the block's `.tag`, or `sha256(uuid).slice(0,16)` fallback |
| `title`                      | string | Display title from the block's UI metadata                                          |
| `description`                | string | Optional description from the block's UI metadata                                   |
| `filterSchema`               | array  | Filter addons configured on this grid                                               |
| `filterSchema[].filterId`    | string | Stable filter identifier                                                            |
| `filterSchema[].title`       | string | Display label                                                                       |
| `filterSchema[].type`        | string | Input type: `dropdown`, `datepicker`, or `input`                                    |
| `filterSchema[].field`       | string | Document field the filter targets                                                   |
| `filterSchema[].operators`   | array  | Operator(s) configured for this filter (e.g. `["eq"]`)                              |
| `columnSchema`               | array  | Columns defined on the grid                                                         |
| `columnSchema[].name`        | string | Field name                                                                          |
| `columnSchema[].title`       | string | Display label                                                                       |
| `columnSchema[].type`        | string | Column data type                                                                    |
| `columnSchema[].bindActions` | array  | Action tags bound to this column                                                    |

### Error Responses

| Status                      | Description                  |
| --------------------------- | ---------------------------- |
| `401 Unauthorized`          | JWT token missing or invalid |
| `403 Forbidden`             | Insufficient permissions     |
| `503 Service Unavailable`   | Policy instance not running  |
| `500 Internal Server Error` | Unexpected server failure    |


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://guardian.hedera.com/developer-tools-and-resources/api-reference/policy-grid-actions/list-grids.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.