About cross-origin requests
A cross-origin request is a request made to a different domain than the one originating the request. For security reasons, most web browsers block cross-origin requests. However, you can use cross-origin resource sharing (CORS) and JSONP callbacks to make cross-origin requests.
Cross-origin resource sharing (CORS)
The REST API supports cross-origin resource sharing (CORS) for AJAX requests from any origin. For more information, see the "CORS W3C Recommendation" and the HTML 5 Security Guide
Here's a sample request sent from a browser hitting
http://example.com
:
$ curl -I http(s)://<em>HOSTNAME</em>/api/v3 -H "Origin: http://example.com"
HTTP/2 302
Access-Control-Allow-Origin: *
Access-Control-Expose-Headers: ETag, Link, X-GitHub-OTP, x-ratelimit-limit, x-ratelimit-remaining, x-ratelimit-reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval
This is what the CORS preflight request looks like:
$ curl -I http(s)://<em>HOSTNAME</em>/api/v3 -H "Origin: http://example.com" -X OPTIONS
HTTP/2 204
Access-Control-Allow-Origin: *
Access-Control-Allow-Headers: Authorization, Content-Type, If-Match, If-Modified-Since, If-None-Match, If-Unmodified-Since, X-GitHub-OTP, X-Requested-With
Access-Control-Allow-Methods: GET, POST, PATCH, PUT, DELETE
Access-Control-Expose-Headers: ETag, Link, X-GitHub-OTP, x-ratelimit-limit, x-ratelimit-remaining, x-ratelimit-reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval
Access-Control-Max-Age: 86400
JSON-P callbacks
You can send a ?callback
parameter to any GET call to have the results
wrapped in a JSON function. This is typically used when browsers want to embed GitHub Enterprise Server content in web pages and avoid cross-domain problems. The response includes the same data output as the regular API, plus the relevant HTTP Header information.
$ curl http(s)://<em>HOSTNAME</em>/api/v3?callback=foo
> /**/foo({
> "meta": {
> "status": 200,
> "x-ratelimit-limit": "5000",
> "x-ratelimit-remaining": "4966",
> "x-ratelimit-reset": "1372700873",
> "Link": [ // pagination headers and other links
> ["http(s)://<em>HOSTNAME</em>/api/v3?page=2", {"rel": "next"}]
> ]
> },
> "data": {
> // the data
> }
> })
You can write a JavaScript handler to process the callback. Here's a minimal example you can try:
<html>
<head>
<script type="text/javascript">
function foo(response) {
var meta = response.meta;
var data = response.data;
console.log(meta);
console.log(data);
}
var script = document.createElement('script');
script.src = 'http(s)://HOSTNAME/api/v3?callback=foo';
document.getElementsByTagName('head')[0].appendChild(script);
</script>
</head>
<body>
<p>Open up your browser's console.</p>
</body>
</html>
All of the headers have the same string value as the HTTP Headers, except Link
. Link
headers are pre-parsed for you and come through as an array of [url, options]
tuples.
For example, a link that looks like this:
Link: <url1>; rel="next", <url2>; rel="foo"; bar="baz"
will look like this in the Callback output:
{
"Link": [
[
"url1",
{
"rel": "next"
}
],
[
"url2",
{
"rel": "foo",
"bar": "baz"
}
]
]
}