Custom Connector: How to POST binary body?

[seadude]

I have some tests working in Postman that POST binary data (.jpg) to an endpoint. This works just fine, but there is no visible schema for the `body` of this request. Its just "binary data" I guess. 

What do I select in PowerApps Custom Connector to allow binary data in the `body`? Do I need a schema of some sort? 

[Syndicate_Admin]

Hi,

Can you please tell us little more what you are trying to do? Where is this binary data coming from? You can probably work with content-type for this. Also look at this article to work with base64 encoding and binary data: https://linnzawwin.blogspot.com/2021/02/handle-base64-and-binary-file-content.html

If this reply answers your question or solves your issue, please ACCEPT AS SOLUTION ☑️. If you find this reply helpful, please consider giving it a LIKE 👍.

[ben11]

I had the same problem and finally figured it out. You can use the Swagger editor and add a body parameter like this:

      parameters:
      - name: body
        in: body
        schema: {type: string, format: binary}

It appears as a string parameter in the swagger editor and on the custom connector testing tab, but then when you're in the actual flow editor you can put the "File content" from a previous step in there and it gets sent as plain binary. I absolutely did not expect that to work, but it does.

Hope that helps anyone else stumbling across this post because they're stuck on the same thing!

Edit: I later noticed that the paconn validate tool gives a warning that "the MIME type 'application/octet-stream' is not supported" when I try to set the content-type. So maybe what I discovered was a dirty hack, and not the intended behaviour after all.

[seadude]

I was able to figure this out. Believe it or not, the Body was not required!

[ben11]

Glad you figured yours out! I just edited my solution to note that I'm still getting an ominous warning. So far it's been working fine, but what I'm doing doesn't seem to be officially supported.

[Cam]

here is an example from Github:
https://github.com/microsoft/PowerPlatformConnectors/blob/master/custom-connectors/ServiceNow/apiDef...

there is an example POST on line 471 - 644,

631-640 contains the file element

i'm not sure what to make of this information.... but hopefully it helps someone 🙂

(there is a content type element on row 611 - 630 too)

note: the above is in JSON, so you will need to convert to YAML to use in your custom connector

https://www.json2yaml.com/

[cachemerrill]

Certainly! Here's a detailed response suitable for a Microsoft forum on how to POST a binary body:

---

To POST a binary body in an HTTP request, you need to ensure that the binary data is correctly formatted and sent to the server. This can be done using various tools and programming languages. Below, I'll demonstrate how you can achieve this using a few different methods:

### Using Postman

Postman is a popular tool for testing APIs. Here’s how you can use it to POST a binary body:

1. **Open Postman** and create a new POST request.
2. **Enter the URL** to which you want to send the binary data.
3. **Go to the Body tab**.
4. Select **binary**.
5. **Upload your binary file** by clicking on the "Select File" button.
6. **Send the request** by clicking the "Send" button.

### Using cURL

cURL is a command-line tool for transferring data using various network protocols. Here’s an example of how to POST a binary file using cURL:

```sh
curl -X POST "http://example.com/upload" -H "Content-Type: application/octet-stream" --data-binary "@path/to/your/file"
```

### Using JavaScript (Node.js)

Here’s an example using Node.js and the `axios` library to send a binary file in a POST request:

1. **Install axios** if you haven’t already:

```sh
npm install axios
```

2. **Create a JavaScript file** and include the following code:

```javascript
const axios = require('axios');
const fs = require('fs');

const url = 'http://example.com/upload';
const pathToFile = 'path/to/your/file';

const binaryData = fs.readFileSync(pathToFile);

axios.post(url, binaryData, {
headers: {
'Content-Type': 'application/octet-stream',
},
})
.then(response => {
console.log('Response:', response.data);
})
.catch(error => {
console.error('Error:', error);
});
```

### Using Python

Python’s `requests` library makes it easy to send HTTP requests, including binary data:

1. **Install the requests library** if you haven’t already:

```sh
pip install requests
```

2. **Create a Python script** and include the following code:

```python
import requests

url = 'http://example.com/upload'
file_path = 'path/to/your/file'

with open(file_path, 'rb') as f:
binary_data = f.read()

headers = {
'Content-Type': 'application/octet-stream',
}

response = requests.post(url, headers=headers, data=binary_data)

print('Response:', response.content)
```

### Using .NET (C#)

Here’s an example using C# to send a binary file in a POST request:

1. **Create a new C# project** or use an existing one.
2. **Include the following code**:

```csharp
using System;
using System.Net.Http;
using System.Threading.Tasks;
using System.IO;

class Program
{
static async Task Main(string[] args)
{
var url = "http://example.com/upload";
var filePath = "path/to/your/file";

using var client = new HttpClient();
using var content = new StreamContent(File.OpenRead(filePath));
content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");

var response = await client.PostAsync(url, content);

var responseString = await response.Content.ReadAsStringAsync();
Console.WriteLine("Response: " + responseString);
}
}
```

Cache Merrill

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