> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.ada.cx/reference/conversations/upload-attachment/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.ada.cx/_mcp/server.

# Upload a file attachment

POST https://example.ada.support/api/v2/conversations/{conversation_id}/attachments/
Content-Type: multipart/form-data

Upload a temporary file attachment to a conversation. The file is stored on Ada-managed
storage and a presigned URL is returned that is valid for up to 7 days. Use that URL to
create a file message by calling the `/v2/conversations/{conversation_id}/messages/`
endpoint with `content.type` set to `file`. The maximum file size is 50MB.

This endpoint provides temporary media storage for use within a conversation. It is
**not** equivalent to the native attachment experience in Ada's widget handoff
integrations (for example, the paperclip in Zendesk Messaging). With native widget
attachments, files are uploaded directly into your agent platform (such as Sunshine
Conversations / Zendesk) and hosted there. That native path is only available to Ada's
web channel and is not accessible through the Conversations API.

If you are building a headless Conversations API integration and want to send an
attachment from an end user to a human agent mid-conversation so that it appears natively
in your agent platform, upload the file using your agent platform's own attachment
endpoints (for example, the Sunshine Conversations Attachments API for Zendesk) and
consult that platform's documentation.

**Note:** Attachments can only be uploaded when the conversation is in a handoff state.

**Allowed file types:** TXT, LOG, CSV, EML, PNG, SVG, JPEG, JPG, GIF, HEIF, HEIC, AVIF, WAV, M4A, MP3, MP4, M4V, MOV, MPEG, MPG, ZIP, PDF, DOC, DOCX, XLS, XLSX, PPT, PPTX, Keynote, Pages, Numbers

Reference: https://docs.ada.cx/reference/conversations/upload-attachment

## Authentication

- `Authorization` header (bearer token, required) — Bearer authentication of the form `Bearer <token>`, where token is your auth token.

## Request

### Path parameters

- `conversation_id` (string, required) — The ID of the conversation

### Body (multipart/form-data)

This endpoint expects a multipart form containing a file.

- `file` (file, required) — The file to upload (max 50MB)

## Response

### 201

Attachment uploaded

- `url` (string, required) — Presigned URL to access the uploaded file (valid for 7 days)
- `mime_type` (string, required) — MIME type of the uploaded file
- `filename` (string, required) — Name of the uploaded file

## Errors

### 400 Bad Request Error

Bad Request

- `errors` (list of ErrorsErrorsItems, required) — A list of errors

### 401 Unauthorized Error

Unauthorized

- `errors` (list of ErrorsErrorsItems, required) — A list of errors

### 404 Not Found Error

Not Found

- `errors` (list of ErrorsErrorsItems, required) — A list of errors

### 429 Too Many Requests Error

Too Many Requests

- `errors` (list of ErrorsErrorsItems, required) — A list of errors

### 500 Internal Server Error

Internal Server Error

- `errors` (list of ErrorsErrorsItems, required) — A list of errors

## Types

### ErrorsErrorsItems

- `type` (string, required) — The error type
- `message` (string, required) — The error message
- `details` (string, optional, nullable) — Extra information about the error

## Examples

**Request**

```json
{
  "file": "<file: string>"
}
```

**Response**

```json
{
  "url": "https://s3.amazonaws.com/bucket/conversations/5df263b7db5a7e6ea03fae9b/5df263b7db5a7e6ea03fae9b/a1b2c3d4-e5f6-7890-abcd-ef1234567890/document.pdf?X-Amz-Algorithm=AWS4-HMAC-SHA256",
  "mime_type": "application/pdf",
  "filename": "document.pdf"
}
```

**SDK Code**

```python
import requests

url = "https://example.ada.support/api/v2/conversations/conversation_id/attachments/"

files = { "file": "open('string', 'rb')" }
headers = {"Authorization": "Bearer <token>"}

response = requests.post(url, files=files, headers=headers)

print(response.json())
```

```javascript
const url = 'https://example.ada.support/api/v2/conversations/conversation_id/attachments/';
const form = new FormData();
form.append('file', 'string');

const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};

options.body = form;

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://example.ada.support/api/v2/conversations/conversation_id/attachments/"

	payload := strings.NewReader("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"string\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001--\r\n")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://example.ada.support/api/v2/conversations/conversation_id/attachments/")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request.body = "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"string\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001--\r\n"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://example.ada.support/api/v2/conversations/conversation_id/attachments/")
  .header("Authorization", "Bearer <token>")
  .body("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"string\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001--\r\n")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://example.ada.support/api/v2/conversations/conversation_id/attachments/', [
  'multipart' => [
    [
        'name' => 'file',
        'filename' => 'string',
        'contents' => null
    ]
  ]
  'headers' => [
    'Authorization' => 'Bearer <token>',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://example.ada.support/api/v2/conversations/conversation_id/attachments/");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
request.AddParameter("undefined", "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"string\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001--\r\n", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["Authorization": "Bearer <token>"]
let parameters = [
  [
    "name": "file",
    "fileName": "string"
  ]
]

let boundary = "---011000010111000001101001"

var body = ""
var error: NSError? = nil
for param in parameters {
  let paramName = param["name"]!
  body += "--\(boundary)\r\n"
  body += "Content-Disposition:form-data; name=\"\(paramName)\""
  if let filename = param["fileName"] {
    let contentType = param["content-type"]!
    let fileContent = String(contentsOfFile: filename, encoding: String.Encoding.utf8)
    if (error != nil) {
      print(error as Any)
    }
    body += "; filename=\"\(filename)\"\r\n"
    body += "Content-Type: \(contentType)\r\n\r\n"
    body += fileContent
  } else if let paramValue = param["value"] {
    body += "\r\n\r\n\(paramValue)"
  }
}

let request = NSMutableURLRequest(url: NSURL(string: "https://example.ada.support/api/v2/conversations/conversation_id/attachments/")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```