feat: /logs debug endpoint with circular buffer

server.mjs

@@ -50,6 +50,25 @@ if (!MCP_TOKEN) {
 const PORT = Number(process.env.PORT || 8935);
 const OUTPUT_DIR = process.env.IMAGE_MCP_OUTPUT_DIR || '/app/generated-images';
 
+// ---------- In-memory circular log buffer (for /logs debug endpoint) ----------
+const LOG_MAX = 500;
+const logBuffer = [];
+function writeLog(msg) {
+  logBuffer.push(msg);
+  if (logBuffer.length > LOG_MAX) logBuffer.shift();
+  process.stderr.write(msg);
+}
+function readLogBuffer(n) {
+  return logBuffer.slice(-n).join('');
+}
+// Override stderr.write to also capture to our buffer
+const origStdErrWrite = process.stderr.write.bind(process.stderr);
+process.stderr.write = (chunk, ...args) => {
+  logBuffer.push(String(chunk));
+  if (logBuffer.length > LOG_MAX) logBuffer.shift();
+  return origStdErrWrite(chunk, ...args);
+};
+
 // ---------- Models that support transparent background ----------
 // Recraft (v3 confirmed via OpenRouter /api/v1/images endpoint, accepts background param)
 // GPT-Image (1/2/5-image) via /chat/completions with image_config.background=transparent
@@ -602,8 +621,8 @@ await mcpServer.connect(mcpTransport);
 const httpServer = http.createServer(async (req, res) => {
   const url = new URL(req.url, `http://${req.headers.host || 'localhost'}`);
 
-  // Auth gate — skip /health and /images/
-  if (!url.pathname.startsWith('/health') && !url.pathname.startsWith('/images/')) {
+  // Auth gate — skip /health, /images/ and /logs
+  if (!url.pathname.startsWith('/health') && !url.pathname.startsWith('/images/') && !url.pathname.startsWith('/logs')) {
     const auth = req.headers.authorization || '';
     const expected = `Bearer ${MCP_TOKEN}`;
     if (auth !== expected) {
@@ -616,7 +635,7 @@ const httpServer = http.createServer(async (req, res) => {
     }
   }
 
-  // Lightweight /health for Coolify / Traefik probes
+// Lightweight /health for Coolify / Traefik probes
   if (url.pathname === '/health') {
     res.statusCode = 200;
     res.setHeader('content-type', 'application/json');
@@ -624,6 +643,16 @@ const httpServer = http.createServer(async (req, res) => {
     return;
   }
 
+  // Recent logs viewer (no auth, for debugging Figma connections)
+  if (url.pathname === '/logs') {
+    const maxLines = parseInt(url.searchParams.get('n') || '50', 10);
+    const logLines = readLogBuffer(maxLines);
+    res.statusCode = 200;
+    res.setHeader('content-type', 'text/plain; charset=utf-8');
+    res.end(logLines);
+    return;
+  }
+
   process.stderr.write(`[HTTP] ${req.method} ${url.pathname} -> incoming\n`);
 
   try {