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

# Update a template

> Rename a template, edit its description or grouping, or replace its columns. The slug never changes, and edits are refused while a migration using the template is running.

```http theme={null}
PATCH https://app.vern.so/api/v1/templates/{template_slug}
```

Partial update of an active template: send any of `name`, `description`,
`grouping`, or `columns` — omitted fields keep their stored value.

<Info>
  The **slug is frozen**: renaming a template changes only its display name,
  never its address. Template references in your integration stay stable across
  renames — the opposite of [sources](/migration-api/update-a-source), which
  are addressed by name.
</Info>

## Authentication

Requires an `x-api-key` header. See [Authentication](/migration-api/authentication).

## Request body

At least one field is required.

<ParamField body="name" type="string">
  New display name. Does not change the slug.
</ParamField>

<ParamField body="description" type="string | null">
  The template's description / knowledge shown to the agent and your team.
  Pass `null` to clear it.
</ParamField>

<ParamField body="grouping" type="string | null">
  Free-text group label used to organise the template list in the Vern
  dashboard. Pass `null` to clear it. Not returned by template reads.
</ParamField>

<ParamField body="columns" type="object[]">
  A **full replacement** of the column set — send every column you want the
  template to have, in order. Each column takes the same shape
  [template reads return](/migration-api/list-templates#fields): `name`
  (required), `description`, `required`, `unique`, `desiredRule`, `strictRule`.
  Cross-cell rules stored on the template are always preserved. Validation-rule
  changes automatically revalidate the sheets already using this template.
</ParamField>

## Response

`200 OK` — the updated template, in the same shape as
[Fetch one template](/migration-api/list-templates#fetch-one-template).

```json theme={null}
{
  "slug": "suppliers",
  "name": "Suppliers",
  "description": "Suppliers master list. One row per active supplier.",
  "columns": [ /* … */ ]
}
```

## Errors

| Status | Meaning                                                                                 |
| ------ | --------------------------------------------------------------------------------------- |
| `400`  | Malformed body, empty body, empty `columns`, or a column without a name.                |
| `401`  | API key missing or invalid.                                                             |
| `404`  | No active template with that slug (archived templates can't be edited through the API). |
| `409`  | A migration that uses this template is currently running — retry after it settles.      |
| `429`  | Rate limit hit — back off and retry.                                                    |
| `500`  | Server error.                                                                           |

## Example

```bash theme={null}
# Update the description
curl -X PATCH https://app.vern.so/api/v1/templates/suppliers \
  -H "x-api-key: $VERN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "description": "Suppliers master list. One row per active supplier." }'

# Replace the column set
curl -X PATCH https://app.vern.so/api/v1/templates/suppliers \
  -H "x-api-key: $VERN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "columns": [
      { "name": "Supplier Name", "description": "Legal entity name", "required": true },
      { "name": "ABN", "required": false, "desiredRule": "strict", "strictRule": "^\\d{11}$" }
    ]
  }'
```

## Next

* [List templates](/migration-api/list-templates) — the current template set and column shapes.
* [Create a migration](/migration-api/create-a-migration) — templates become the migration's sheets.