## On this page

Binary resources containing non-FHIR data such as images or PDF documents are often used to enrich and add context to clinical resources. If an unauthenticated user needs to read or write those files, this can be allowed by generating a pre-signed URL for the Binary. Any user can access this temporary secure URL to either read the contents of the file, or to write new data to the Binary.

## Invocation

```text
GET [base]/Binary/[id]/$presigned-url
```

## Input Query Parameters

| Parameter | Cardinality | Type | Description |
| --- | --- | --- | --- |
| `upload` | 0..1 | `boolean` | Whether the link is used for reading (default = false) or writing (set to true) |

## Output Parameters

| Parameter | Cardinality | Type | Description |
| --- | --- | --- | --- |
| `url` | 1..1 | `string` | The presigned URL granting read or write access to the Binary contents |

## Example

### Request

**Read URL:**

```http
GET /fhir/R4/Binary/[id]/$presigned-url
```

**Write URL:**

```http
GET /fhir/R4/Binary/[id]/$presigned-url?upload=true
```

### Response

```json
{

"resourceType": "Parameters",

"parameter": [

{

"name": "url",

"valueUri": "https://storage.medplum.com/binary/c138a343-02e1-40f0-801f-e3d7f5317d4e/f4609304-c1ca-4a5b-af7d-77a289a2ac55?Signature=RJKaFn[...]"

}

]

}
```

### Using the Presigned URL

**Warning:** The generated presigned URLs are **unauthenticated**, and can be accessed by anyone who has the URL without an access token. Care should be taken to ensure that the URLs are restricted to the intended users.

For reads/downloads, the URL can be accessed directly to retrieve the Binary contents:

```bash
curl 'https://storage.medplum.com/binary/c138a343-02e1-40f0-801f-e3d7f5317d4e/f4609304-c1ca-4a5b-af7d-77a289a2ac55?Signature=RJKaFn[...]'
```

To send data to a presigned upload URL, use an HTTP PUT request with the same content type as defined in the resource's `Binary.contentType` field:

```bash
curl -X PUT 'https://storage.medplum.com/binary/c138a343-02e1-40f0-801f-e3d7f5317d4e/f4609304-c1ca-4a5b-af7d-77a289a2ac55?Signature=RJKaFn[...]' \

-H 'Content-Type: text/plain'

--data-raw 'lorem ipsum dolor sit amet...'
```

- [Invocation](/content/docs/api/fhir/operations/binary-presigned-url#invocation/index.html)
- [Input Query Parameters](/content/docs/api/fhir/operations/binary-presigned-url#input-query-parameters/index.html)
- [Output Parameters](/content/docs/api/fhir/operations/binary-presigned-url#output-parameters/index.html)
- [Example](/content/docs/api/fhir/operations/binary-presigned-url#example/index.html)  
  - [Request](/content/docs/api/fhir/operations/binary-presigned-url#request/index.html)  
  - [Response](/content/docs/api/fhir/operations/binary-presigned-url#response/index.html)  
  - [Using the Presigned URL](/content/docs/api/fhir/operations/binary-presigned-url#using-the-presigned-url/index.html)