Add /pressure endpoint, bump maxTabs to 20, expose pool stats

- GET /pressure returns activeTabs, pendingTabs, capacity per browser
- Default maxTabs bumped from 2 to 20 (configurable via MAX_TABS_PER_BROWSER)
- ChromeInstanceStats now includes pendingTabs and maxTabs
- ReaderClient.getPoolStats() exposes pool stats for daemon use

Author: nihalwashere

src/browser/playwright-pool.ts

@@ -73,6 +73,8 @@ export interface ChromeInstanceStats {
   proxyUrl: string | null;
   state: "launching" | "active" | "retired" | "closed";
   activeTabs: number;
+  pendingTabs: number;
+  maxTabs: number;
   totalPages: number;
 }
 
@@ -125,7 +127,7 @@ export class ChromeInstance {
     logger?: Logger;
   }) {
     this.proxyUrl = options.proxyUrl;
-    this.maxTabs = options.maxTabs ?? 2;
+    this.maxTabs = options.maxTabs ?? 20;
     this.retireAfterPages = options.retireAfterPages ?? 100;
     this.showChrome = options.showChrome ?? false;
     this.userAgent = options.userAgent;
@@ -158,6 +160,8 @@ export class ChromeInstance {
       proxyUrl: this.proxyUrl,
       state: this.state,
       activeTabs: this.limit.activeCount,
+      pendingTabs: this.limit.pendingCount,
+      maxTabs: this.maxTabs,
       totalPages: this.totalPages,
     };
   }

src/client.ts

@@ -247,7 +247,7 @@ export class ReaderClient {
 
       this.pool = new PlaywrightPool({
         tiers: tierConfigs,
-        maxTabsPerBrowser: 10,
+        maxTabsPerBrowser: parseInt(process.env.MAX_TABS_PER_BROWSER || "20", 10),
         retireAfterPages: this.options.browserPool?.retireAfterPages ?? 100,
         showChrome: this.options.showChrome,
         userAgent: this.options.userAgent,
@@ -426,6 +426,10 @@ export class ReaderClient {
     return this.initialized && !this.closed;
   }
 
+  getPoolStats(): import("./browser/playwright-pool.js").PoolStatsSnapshot | null {
+    return this.pool?.getStats() ?? null;
+  }
+
   /**
    * Close the client and release resources
    *

src/daemon/server.ts

@@ -318,6 +318,13 @@ export class DaemonServer {
       return;
     }
 
+    // Pressure: per-browser load metrics for smart routing
+    if (method === "GET" && url === "/pressure") {
+      if (!this.checkAuth(req, res)) return;
+      this.handlePressure(res);
+      return;
+    }
+
     // --- POST / (existing action-based RPC) ---
 
     if (method !== "POST" || url !== "/") {
@@ -486,6 +493,34 @@ export class DaemonServer {
     this.sendResponse<DaemonStatus>(res, 200, { success: true, data: status });
   }
 
+  private handlePressure(res: http.ServerResponse): void {
+    const poolStats = this.client?.getPoolStats();
+    let activeTabs = 0;
+    let pendingTabs = 0;
+    let capacity = 0;
+
+    const tiers =
+      poolStats?.tiers.map((t) => {
+        const browsers = t.browsers.map((b) => {
+          activeTabs += b.activeTabs;
+          pendingTabs += b.pendingTabs;
+          if (b.state === "active") capacity += b.maxTabs;
+          return {
+            activeTabs: b.activeTabs,
+            pendingTabs: b.pendingTabs,
+            maxTabs: b.maxTabs,
+            state: b.state,
+          };
+        });
+        return { tier: t.tier, browsers };
+      }) ?? [];
+
+    this.sendResponse(res, 200, {
+      success: true,
+      data: { activeTabs, pendingTabs, capacity, activeRequests: this.activeRequests, tiers },
+    });
+  }
+
   /**
    * Handle shutdown request
    */