# Update a function

> API Reference / Functions / Update a function

## PATCH /projects//branches//functions/

Updates the function's mutable metadata — currently only the display
`name`. A string sets the display name; `null` clears it, after which
the function's `name` falls back to its slug. Leading and trailing
whitespace is trimmed; a whitespace-only name is rejected. Acts only
on a function owned by the branch: a slug that is only inherited from
an ancestor branch returns 404 — rename it on the branch that owns
it. Like every other change on a branch, a rename is isolated per
branch: a branch forked before the rename keeps the name it had at
fork time.

**Note**: This endpoint is currently in Beta.

### Parameters

- `project_id` (string, path, required)
  The Neon project ID
- `branch_id` (string, path, required)
  The Neon branch ID
- `slug` (string, path, required)
  The function slug

### Request body

- `name` (string, required)
  New display name for the function. `null` clears the display
  name; the function's `name` then falls back to its slug. Leading
  and trailing whitespace is trimmed; a whitespace-only name is
  rejected.

### Response (200)

```json
{
  "function": {
    "id": "myfunction",
    "slug": "myfunction",
    "name": "My Function",
    "invocation_url": "https://br-young-forest-a5b6c7d8-myfunction.compute.c-5.us-east-2.aws.neon.tech/",
    "current_deployment": {
      "id": 10,
      "status": "completed",
      "memory_mib": 2048,
      "runtime": "nodejs24",
      "created_at": "2025-01-15T10:30:00Z"
    },
    "active_deployment": {
      "id": 10,
      "status": "completed",
      "memory_mib": 2048,
      "runtime": "nodejs24",
      "created_at": "2025-01-15T10:30:00Z"
    },
    "created_at": "2025-01-15T11:00:00Z"
  }
}
```

### Code examples

```bash
curl "https://console.neon.tech/api/v2/projects/$PROJECT_ID/branches/$BRANCH_ID/functions/$SLUG" \
  -X PATCH \
  -H "Authorization: Bearer $NEON_API_KEY"
```

```typescript
import { createNeonClient, raw } from '@neon/sdk';

const neon = createNeonClient({ apiKey: process.env.NEON_API_KEY });
const { data } = await raw.updateProjectBranchFunction({
  client: neon.client,
  path: {
    project_id: process.env.PROJECT_ID,
    branch_id: process.env.BRANCH_ID,
    slug: process.env.SLUG
  }
});
```

### Errors

**default**
General Error.

The request may or may not be safe to retry, depending on the HTTP method, response status code,
and whether a response was received.

- If no response is returned from the API, a network error or timeout likely occurred.
- In some cases, the request may have reached the server and been successfully processed, but the response failed to reach the client. As a result, retrying non-idempotent requests can lead to unintended results.

The following HTTP methods are considered non-idempotent: `POST`, `PATCH`, `DELETE`, and `PUT`. Retrying these methods is generally **not safe**.
The following methods are considered idempotent: `GET`, `HEAD`, and `OPTIONS`. Retrying these methods is **safe** in the event of a network error or timeout.

Any request that returns a `503 Service Unavailable` response is always safe to retry.

Any request that returns a `423 Locked` response is safe to retry. `423 Locked` indicates that the resource is temporarily locked, for example, due to another operation in progress.

- `request_id` (string, optional)
  Unique identifier for the request, useful for debugging.
  You can set this value manually by including an `X-Request-ID` header in the request. If not provided, the value will be generated automatically.

- `code` (string, required)
  Machine-readable code classifying the error type. See `message` for a human-readable explanation.
  Default: \`\`

- `message` (string, required)
  Error message

## Related pages

- [Create a trigger](./apis-sdks-reference-api-functions-create-project-branch-trigger.md)
- [Delete a custom domain from a branch](./apis-sdks-reference-api-functions-delete-project-branch-custom-domain.md)
- [Delete a function on the branch](./apis-sdks-reference-api-functions-delete-project-branch-function.md)
- [Delete a trigger](./apis-sdks-reference-api-functions-delete-project-branch-trigger.md)
- [Deploy code to a function](./apis-sdks-reference-api-functions-create-project-branch-function-deployment.md)
- [Get a trigger](./apis-sdks-reference-api-functions-get-project-branch-trigger.md)
- [Get function details](./apis-sdks-reference-api-functions-get-project-branch-function.md)
- [List functions on the branch](./apis-sdks-reference-api-functions-list-project-branch-functions.md)
- [List the custom domains on a branch](./apis-sdks-reference-api-functions-list-project-branch-custom-domains.md)
- [List triggers on the branch](./apis-sdks-reference-api-functions-list-project-branch-triggers.md)

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