Sending a message with ContentType application/json won't work

Question

I'm trying to send a message with a JSON payload using boto3:

https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/connectparticipant/client/send_message.html

```python
response = client.send_message(
        ContentType='application/json',
        Content=json.dumps({'key': 'value'}),
        ConnectionToken=connection_token
    )
```

However, I always get this error: 
```
An error occurred (ValidationException) when calling the SendMessage operation: Specified request parameter(s) are invalid.
```

If I switch the ContentType to text/plain, everything works fine. Is this a bug, or am I making a mistake?

Edit: Fixed typo

David C · Answer

Looking at the code you provided, it looks like you are missing a closing single quotation mark in the json.dumps line. The ~~**'value**~~ should be **'value'.** This might be causing the error you're experiencing.

```
import json

response = client.send_message(
    ContentType='application/json',
    Content=json.dumps({'key': 'value'}),
    ConnectionToken=connection_token
)
```

Sending a message with ContentType application/json won't work

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