Glean common errors

Glean Common Errors

Overview

Glean provides enterprise search across connected data sources with AI-powered results. API integrations involve two distinct token types (indexing vs. client) and a custom datasource model for pushing content. Common errors stem from token type mismatches, permission misconfiguration that silently hides documents from search results, and bulk indexing failures caused by duplicate upload IDs or oversized documents. Stale results are a frequent complaint -- Glean indexes asynchronously, so newly pushed documents may take 1-5 minutes to appear in search. This reference covers authentication, indexing pipeline, and search-time issues.

Error Reference

Code	Message	Cause	Fix
401	Unauthorized	Invalid or expired API token	Regenerate at Admin > Settings > API Tokens
403	Wrong token type	Using indexing token for search API	Indexing API needs indexing token; Client API needs client token with X-Glean-Auth-Type: BEARER
400	uploadId already used	Duplicate bulk upload identifier	Generate a unique UUID per upload run
400	document too large	Document body exceeds 100KB limit	Truncate or split content before indexing
400	invalid datasource	Datasource not registered	Create datasource first via adddatasource endpoint
400	missing required field	Document lacks id or title	Ensure every document has both id and title fields
403	Permission denied	Document visibility restricted	Set allowAnonymousAccess: true or add user/group to permissions
429	Rate limit exceeded	Too many API requests	Implement exponential backoff; batch indexing calls

Error Handler

interface GleanError {
  code: number;
  message: string;
  category: "auth" | "rate_limit" | "indexing" | "permission";
}

function classifyGleanError(status: number, body: string): GleanError {
  if (status === 401) {
    return { code: 401, message: body, category: "auth" };
  }
  if (status === 429) {
    return { code: 429, message: "Rate limit exceeded", category: "rate_limit" };
  }
  if (status === 403 && body.includes("permission")) {
    return { code: 403, message: body, category: "permission" };
  }
  if (status === 400) {
    return { code: 400, message: body, category: "indexing" };
  }
  return { code: status, message: body, category: "auth" };
}

Debugging Guide

Authentication Errors

Glean uses two distinct token types. Indexing tokens authenticate bulk document uploads. Client tokens authenticate search queries and require the X-Glean-Auth-Type: BEARER header. Using the wrong token type returns 403, not 401 -- check the token type first.

Rate Limit Errors

Glean enforces per-token rate limits. Indexing operations should batch documents (up to 100 per request). Search queries are rate-limited per client token. Use Retry-After header when present and implement exponential backoff starting at 2 seconds.

Validation Errors

Bulk index uploads require a unique uploadId per run -- reusing an ID silently drops the upload. Documents must include both id and title fields. Content bodies over 100KB are rejected; truncate or split large documents. New datasources must be registered via adddatasource before any documents can be indexed against them. The datasource field in each document must exactly match the registered datasource name (case-sensitive).

Error Handling

Scenario	Pattern	Recovery
No search results after indexing	Processing delay (1-5 min)	Wait 5 minutes, then verify with direct document lookup
Stale results returned	Index not refreshed	Trigger re-index; check datasource sync schedule
Permission mismatch	User lacks document access	Add user/group to document permissions or enable anonymous access
Bulk upload silently dropped	Duplicate uploadId	Always generate fresh UUID per upload run
Token type confusion	403 on search or index	Verify correct token type for the API being called

Quick Diagnostic

# Verify client token connectivity
curl -s -o /dev/null -w "%{http_code}" \
  -H "Authorization: Bearer $GLEAN_API_KEY" \
  -H "X-Glean-Auth-Type: BEARER" \
  https://your-domain.glean.com/api/v1/search

Resources

• Glean Developer Portal
• Indexing API Docs

Next Steps

See glean-debug-bundle.