使用Cloudflare workers反代OpenAI API

在Cloudflare新建一个worker，填入以下代码即可。代码来源于GitHub，版权归原作者所有。

// Website you intended to retrieve for users.

const upstream = 'api.openai.com'

// Custom pathname for the upstream website.

const upstream_path = '/'

// Website you intended to retrieve for users using mobile devices.

const upstream_mobile = upstream

// Countries and regions where you wish to suspend your service.

const blocked_region = []

// IP addresses which you wish to block from using your service.

const blocked_ip_address = ['0.0.0.0', '127.0.0.1']

// Whether to use HTTPS protocol for upstream address.

const https = true

// Whether to disable cache.

const disable_cache = false

// Replace texts.

const replace_dict = {

'$upstream': '$custom_domain',

}

addEventListener('fetch', event => {

event.respondWith(fetchAndApply(event.request));

})

async function fetchAndApply(request) {

const region = request.headers.get('cf-ipcountry').toUpperCase();

const ip_address = request.headers.get('cf-connecting-ip');

const user_agent = request.headers.get('user-agent');

let response = null;

let url = new URL(request.url);

let url_hostname = url.hostname;

if (https == true) {

url.protocol = 'https:';

} else {

url.protocol = 'http:';

}

if (await device_status(user_agent)) {

var upstream_domain = upstream;

} else {

var upstream_domain = upstream_mobile;

}

url.host = upstream_domain;

if (url.pathname == '/') {

url.pathname = upstream_path;

} else {

url.pathname = upstream_path + url.pathname;

}

if (blocked_region.includes(region)) {

response = new Response('Access denied: WorkersProxy is not available in your region yet.', {

status: 403

});

} else if (blocked_ip_address.includes(ip_address)) {

response = new Response('Access denied: Your IP address is blocked by WorkersProxy.', {

status: 403

});

} else {

let method = request.method;

let request_headers = request.headers;

let new_request_headers = new Headers(request_headers);

new_request_headers.set('Host', upstream_domain);

new_request_headers.set('Referer', url.protocol + '//' + url_hostname);

let original_response = await fetch(url.href, {

method: method,

headers: new_request_headers,

body: request.body

})

connection_upgrade = new_request_headers.get("Upgrade");

if (connection_upgrade && connection_upgrade.toLowerCase() == "websocket") {

return original_response;

}

let original_response_clone = original_response.clone();

let original_text = null;

let response_headers = original_response.headers;

let new_response_headers = new Headers(response_headers);

let status = original_response.status;

if (disable_cache) {

new_response_headers.set('Cache-Control', 'no-store');

}

new_response_headers.set('access-control-allow-origin', '*');

new_response_headers.set('access-control-allow-credentials', true);

new_response_headers.delete('content-security-policy');

new_response_headers.delete('content-security-policy-report-only');

new_response_headers.delete('clear-site-data');

if (new_response_headers.get("x-pjax-url")) {

new_response_headers.set("x-pjax-url", response_headers.get("x-pjax-url").replace("//" + upstream_domain, "//" + url_hostname));

}

const content_type = new_response_headers.get('content-type');

if (content_type != null && content_type.includes('text/html') && content_type.includes('UTF-8')) {

original_text = await replace_response_text(original_response_clone, upstream_domain, url_hostname);

} else {

original_text = original_response_clone.body

}

response = new Response(original_text, {

status,

headers: new_response_headers

})

}

return response;

}

async function replace_response_text(response, upstream_domain, host_name) {

let text = await response.text()

var i, j;

for (i in replace_dict) {

j = replace_dict[i]

if (i == '$upstream') {

i = upstream_domain

} else if (i == '$custom_domain') {

i = host_name

}

if (j == '$upstream') {

j = upstream_domain

} else if (j == '$custom_domain') {

j = host_name

}

let re = new RegExp(i, 'g')

text = text.replace(re, j);

}

return text;

}

async function device_status(user_agent_info) {

var agents = ["Android", "iPhone", "SymbianOS", "Windows Phone", "iPad", "iPod"];

var flag = true;

for (var v = 0; v < agents.length; v++) {

if (user_agent_info.indexOf(agents[v]) > 0) {

flag = false;

break;

}

}

return flag;

}

还有一种更简单的方法，目前Cloudflare提供了官方的OpenAI api反代，即Cloudflare AI Gateway，具体看这里：https://developers.cloudflare.com/ai-gateway/providers/openai/，格式是https://gateway.ai.cloudflare.com/v1/ACCOUNT_TAG/GATEWAY/openai

登录自己的Cloudflare账号即可看到具体的api地址。