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fix: ensure Content-Type headers and add keep-alive for OpenAI fake stream #48

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Merged
bbbugg merged 1 commit into from
Jan 29, 2026
Merged

fix: ensure Content-Type headers and add keep-alive for OpenAI fake stream #48

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143 changes: 90 additions & 53 deletions src/core/RequestHandler.js
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Original file line number Diff line number Diff line change
Expand Up @@ -518,53 +518,85 @@ class RequestHandler {
this.logger.info(`[Adapter] OpenAI streaming response (Real Mode) started...`);
await this._streamOpenAIResponse(messageQueue, res, model);
} else {
const result = await this._executeRequestWithRetries(proxyRequest, messageQueue);
// OpenAI Fake Stream / Non-Stream mode
// Set up keep-alive timer for fake stream mode to prevent client timeout
let connectionMaintainer;
if (isOpenAIStream) {
const scheduleNextKeepAlive = () => {
const randomInterval = 12000 + Math.floor(Math.random() * 6000); // 12 - 18 seconds
connectionMaintainer = setTimeout(() => {
if (!res.headersSent) {
res.status(200).set({
"Cache-Control": "no-cache",
Connection: "keep-alive",
"Content-Type": "text/event-stream",
});
}
if (!res.writableEnded) {
res.write(": keep-alive\n\n");
scheduleNextKeepAlive();
}
}, randomInterval);
};
scheduleNextKeepAlive();
}

if (!result.success) {
// Send standard HTTP error response for both streaming and non-streaming
// if the error happens before the stream starts.
this._sendErrorResponse(res, result.error.status || 500, result.error.message);
try {
const result = await this._executeRequestWithRetries(proxyRequest, messageQueue);

// Handle account switch without sending callback to client
await this.authSwitcher.handleRequestFailureAndSwitch(result.error, null);
return;
}
if (!result.success) {
// Send standard HTTP error response for both streaming and non-streaming
if (connectionMaintainer) clearTimeout(connectionMaintainer);
this._sendErrorResponse(res, result.error.status || 500, result.error.message);

if (this.authSwitcher.failureCount > 0) {
this.logger.info(`✅ [Auth] OpenAI interface request successful - failure count reset to 0`);
this.authSwitcher.failureCount = 0;
}
// Handle account switch without sending callback to client
await this.authSwitcher.handleRequestFailureAndSwitch(result.error, null);
return;
}

if (isOpenAIStream) {
// Fake stream
res.status(200).set({
"Cache-Control": "no-cache",
Connection: "keep-alive",
"Content-Type": "text/event-stream",
});
this.logger.info(`[Adapter] OpenAI streaming response (Fake Mode) started...`);
let fullBody = "";
let streaming = true;
while (streaming) {
const message = await messageQueue.dequeue();
if (message.type === "STREAM_END") {
streaming = false;
break;
if (this.authSwitcher.failureCount > 0) {
this.logger.info(`✅ [Auth] OpenAI interface request successful - failure count reset to 0`);
this.authSwitcher.failureCount = 0;
}

if (isOpenAIStream) {
// Fake stream - ensure headers are set before sending data
if (!res.headersSent) {
res.status(200).set({
"Cache-Control": "no-cache",
Connection: "keep-alive",
"Content-Type": "text/event-stream",
});
}
if (message.data) fullBody += message.data;
// Clear keep-alive timer as we are about to send real data
if (connectionMaintainer) clearTimeout(connectionMaintainer);

this.logger.info(`[Adapter] OpenAI streaming response (Fake Mode) started...`);
let fullBody = "";
let streaming = true;
while (streaming) {
const message = await messageQueue.dequeue();
if (message.type === "STREAM_END") {
streaming = false;
break;
}
if (message.data) fullBody += message.data;
}
const streamState = {};
const translatedChunk = this.formatConverter.translateGoogleToOpenAIStream(
fullBody,
model,
streamState
);
if (translatedChunk) res.write(translatedChunk);
res.write("data: [DONE]\n\n");
this.logger.info("[Adapter] Fake mode: Complete content sent at once.");
} else {
// Non-stream
await this._sendOpenAINonStreamResponse(messageQueue, res, model);
}
const streamState = {};
const translatedChunk = this.formatConverter.translateGoogleToOpenAIStream(
fullBody,
model,
streamState
);
if (translatedChunk) res.write(translatedChunk);
res.write("data: [DONE]\n\n");
this.logger.info("[Adapter] Fake mode: Complete content sent at once.");
} else {
// Non-stream
await this._sendOpenAINonStreamResponse(messageQueue, res, model);
} finally {
if (connectionMaintainer) clearTimeout(connectionMaintainer);
}
}
} catch (error) {
Expand Down Expand Up @@ -617,6 +649,8 @@ class RequestHandler {
const result = await this._executeRequestWithRetries(proxyRequest, messageQueue);

if (!result.success) {
clearTimeout(connectionMaintainer);

if (result.error.message?.includes("The user aborted a request")) {
this.logger.info(
`[Request] Request #${proxyRequest.request_id} was properly cancelled by user, not counted in failure statistics.`
Expand All @@ -642,6 +676,14 @@ class RequestHandler {
this.authSwitcher.failureCount = 0;
}

if (!res.headersSent) {
res.setHeader("Content-Type", "text/event-stream");
res.setHeader("Cache-Control", "no-cache");
res.setHeader("Connection", "keep-alive");
}
// Clear the keep-alive timer as we are about to send real data
clearTimeout(connectionMaintainer);

// Read all data chunks until STREAM_END to handle potential fragmentation
let fullData = "";
let streaming = true;
Expand Down Expand Up @@ -781,6 +823,10 @@ class RequestHandler {
}

this._setResponseHeaders(res, headerMessage, req);
// Fallback: Ensure Content-Type is set for streaming response
if (!res.get("Content-Type")) {
res.type("text/event-stream");
}
this.logger.info("[Request] Starting streaming transmission...");
try {
let lastChunk = "";
Expand Down Expand Up @@ -1066,18 +1112,9 @@ class RequestHandler {
if ((lowerName === "x-goog-upload-url" || lowerName === "location") && value.includes("googleapis.com")) {
try {
const urlObj = new URL(value);
// Construct local proxy URL using configured host/port
// Note: The client (build.js) might have already embedded the original host in __proxy_host__
// But wait, headerMessage comes from the BROWSER.
// If the Browser sends back the header as received from Google, then it's the GOOGLE URL.
// If the Browser rewrote it, it's the LOCALHOST URL.
// build.js `_transmitHeaders` rewrites it!

// So `value` is `http://localhost:xxxx/...&__proxy_host__=google.com` (from Browser)
// We just need to ensure it points to *our* current listener address.

// Use the Host header from the request to support remote clients (e.g. Docker IPs)
// If req.headers.host exists (standard), use it. Otherwise fallback to config.
// Rewrite upload/redirect URLs to point to this proxy server
// build.js already rewrote the URL to localhost with __proxy_host__ param
// Here we just ensure it matches the client's request host (for Docker/remote access)
let newAuthority;
if (req && req.headers && req.headers.host) {
newAuthority = req.headers.host;
Expand Down
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