Lots of services (Twitter! Twilio! Google!) let you use them by sending them HTTP requests. If an HTTP API doesn’t come with a client library, don’t be scared! You can just make the HTTP requests yourself. Here’s what you need to remember:

Set the right Content—Type header

Often you’ll be sending a POST request with a body, and that means you need a Content—Type header that matches the body.

The 2 main options are: - application/json (JSON!) - application/x-www-form-urlencoded (same as what an HTML form does)

If you don’t set the Content—Type, your request won’t work.

Smiling stick figure with short curly hair: a common error is to try to send POST data as one content type (like JSON) when it’s actually another (like application/x-www-form-urlencoded)

Identify yourself

Most HTTP APIs require a secret API key so they know who you are. Here’s how that looks for the Twilio API:

curl
https://api.twilio.com/2010-04-01/Accounts/ACCOUNT_ID/Messages.json
    -H "Content-Type: application/json"
    -u CCOUNT_ID:AUTH_TOKEN
    -d '{
       "from": "+15141234567",
       "to": "+15141234567",
       "body": "a text message"
}'

(this sends a POST request)

u ACCOUNT_ID:AUTHO_TOKEN sends the username/password in the Authorization