Firestore: REST vs Admin SDK

As of: 2026-08

The problem

firebase-admin pulls a JWT stack including buffer-equal-constant-time, which breaks under Node 25's stricter ESM/require interop in some environments. Symptom: ERR_REQUIRE_ESM or silent import failure at boot, on scripts that worked on Node 22.

The fix that always works

1. gcloud auth print-access-token (or a service-account-signed JWT) → bearer token.
2. Call REST directly:

GET https://firestore.googleapis.com/v1/projects/PROJECT/databases/(default)/documents/COLLECTION?pageSize=50
Authorization: Bearer $TOKEN

3. Structured queries via POST …/documents:runQuery with the same JSON the console uses.

When the SDK is still right

Long-lived servers on Node LTS using connection pooling and bulkWriter. For one-off scripts, cron jobs and agent-run operations, prefer REST — no dependency surface, explicit wire format, easy to audit.