Yo, had the same problem last week! Turns out my JSON was valid but the server expected the data to be URL-encoded. Weird, right?
Try this:
```bash
curl -X POST https://example.com/api \
-H "Content-Type: application/x-www-form-urlencoded" \
-d "param1=value1¶m2=value2"
```
If that works, then the server’s just picky. For debugging, `-i` shows response headers, which might give a clue.
Also, Postman is great for testing before translating to curl post requests.
Try this:
```bash
curl -X POST https://example.com/api \
-H "Content-Type: application/x-www-form-urlencoded" \
-d "param1=value1¶m2=value2"
```
If that works, then the server’s just picky. For debugging, `-i` shows response headers, which might give a clue.
Also, Postman is great for testing before translating to curl post requests.
