Glean Webhooks & Events

Overview

Glean uses an event-driven indexing model where source system webhooks trigger incremental updates to the Glean Indexing API. Instead of emitting its own webhooks, Glean receives document changes from platforms like GitHub, Confluence, and Notion. You can also monitor internal Glean events such as document indexing completion, permission changes, connector sync status, and search anomalies through the admin API.

Webhook Registration

// Register a source system webhook that pushes to Glean Indexing API
const response = await fetch("https://yourapp.com/admin/webhooks", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    url: "https://yourapp.com/webhooks/glean-indexer",
    events: ["document.indexed", "permission.changed", "connector.synced", "search.anomaly"],
    secret: process.env.GLEAN_WEBHOOK_SECRET,
  }),
});

Signature Verification

import crypto from "crypto";
import { Request, Response, NextFunction } from "express";

function verifyGleanSignature(req: Request, res: Response, next: NextFunction) {
  const signature = req.headers["x-glean-signature"] as string;
  const expected = crypto.createHmac("sha256", process.env.GLEAN_WEBHOOK_SECRET!)
    .update(req.body).digest("hex");
  if (!crypto.timingSafeEqual(Buffer.from(signature), Buffer.from(expected))) {
    return res.status(401).json({ error: "Invalid signature" });
  }
  next();
}

Event Handler

import express from "express";
const app = express();

app.post("/webhooks/glean-indexer", express.raw({ type: "application/json" }), verifyGleanSignature, (req, res) => {
  const event = JSON.parse(req.body.toString());
  res.status(200).json({ received: true });

  switch (event.type) {
    case "document.indexed":
      confirmIndexStatus(event.data.datasource, event.data.doc_id); break;
    case "permission.changed":
      reindexPermissions(event.data.datasource, event.data.object_id); break;
    case "connector.synced":
      logSyncMetrics(event.data.connector_name, event.data.docs_processed); break;
    case "search.anomaly":
      alertOps(event.data.query_pattern, event.data.anomaly_type); break;
  }
});

Event Types

Retry & Idempotency

const processed = new Set<string>();

async function handleIdempotent(event: { id: string; type: string; data: any }) {
  if (processed.has(event.id)) return;
  await routeEvent(event);
  processed.add(event.id);
  if (processed.size > 10_000) {
    const entries = Array.from(processed);
    entries.slice(0, entries.length - 10_000).forEach((id) => processed.delete(id));
  }
}

Error Handling

Resources

• Glean Indexing API

Next Steps

See glean-security-basics.