invalid property path "a b". unquoted property paths must match regex ([a-za-z_][a-za-z_#-#]*), and quoted property paths must match regex (`(?:[^`\\]|(?:\\.))+`)

Cloud Firestore (Firebase) REST API · GET /v1/projects/{project}/databases/{database}/documents/{collection} · HTTP 400 INVALID_ARGUMENT

Status: ✅ verified:server:prod · first seen 2026-10-24 · last confirmed 2026-10-27 · 73 confirmations from 2 vantages

A mask.fieldPaths entry with a space or other character outside [a-zA-Z_][a-zA-Z_0-9]* returns HTTP 400 "Invalid property path" unless the path is quoted in backticks.

What to do

  1. No client-side fix known (by design).

Dimensions

env: prod · plan: any · region: any · account_state: service_account

Evidence

Probe af:google-firestore:probe:list-parameter-errors (declarative, source)

Observations: none from reporters yet.

Machine access

curl -s https://apifacts.dev/v0/check \
  -H 'content-type: application/json' \
  -d '{"target":{"method":"GET","url":"https://firestore.googleapis.com/v1/projects/{project}/databases/{database}/documents/{collection}"},"error":{"status":400,"body_excerpt":"invalid property path \"a b\". unquoted property paths must match regex ([a-za-z_][a-za-z_#-#]*), and quoted property paths must match regex (`(?:[^`\\\\]|(?:\\\\.))+`)"}}'

YAML: facts/google-firestore/invalid-field-path-400.yaml

Data: CC BY 4.0 · apifacts registry · This page is generated; edit the YAML, not the page.