Managing Firebase Messaging

Firebase Cloud Messaging Management Skill

Manage and analyze Firebase Cloud Messaging resources including messages, topics, and delivery.

API Conventions

Authentication

All API calls use OAuth 2.0 Bearer token from service account, injected automatically.

Base URL

https://fcm.googleapis.com/v1/projects/$FIREBASE_PROJECT_ID

Core Helper Function

#!/bin/bash

fcm_api() {
    local method="$1"
    local endpoint="$2"
    local data="${3:-}"

    if [ -n "$data" ]; then
        curl -s -X "$method" \
            -H "Authorization: Bearer $FIREBASE_ACCESS_TOKEN" \
            -H "Content-Type: application/json" \
            "https://fcm.googleapis.com/v1/projects/${FIREBASE_PROJECT_ID}${endpoint}" \
            -d "$data"
    else
        curl -s -X "$method" \
            -H "Authorization: Bearer $FIREBASE_ACCESS_TOKEN" \
            "https://fcm.googleapis.com/v1/projects/${FIREBASE_PROJECT_ID}${endpoint}"
    fi
}

# Instance ID API for topic management
iid_api() {
    local method="$1"
    local endpoint="$2"
    curl -s -X "$method" \
        -H "Authorization: Bearer $FIREBASE_ACCESS_TOKEN" \
        "https://iid.googleapis.com${endpoint}"
}

Output Rules

• Target ≤50 lines per script output
• Use jq to extract only needed fields
• Never dump full API responses

Phase 1: Discovery

#!/bin/bash
echo "=== Project Configuration ==="
curl -s -H "Authorization: Bearer $FIREBASE_ACCESS_TOKEN" \
    "https://firebase.googleapis.com/v1beta1/projects/${FIREBASE_PROJECT_ID}" \
    | jq '{projectId: .projectId, displayName: .displayName, state: .state}'

echo ""
echo "=== FCM Send Test ==="
RESULT=$(fcm_api POST "/messages:send" '{"message": {"topic": "__test__", "notification": {"title": "test", "body": "test"}, "dry_run": true}}' 2>/dev/null)
echo "$RESULT" | jq '{status: (if .error then "error: \(.error.message)" else "healthy" end)}' 2>/dev/null || echo "FCM API reachable"

echo ""
echo "=== Topic Subscription Check (sample token) ==="
echo "Note: FCM does not have a list-all-topics API. Check specific tokens with IID API."

Phase 2: Analysis

Delivery Analytics (via BigQuery export)

#!/bin/bash
echo "=== FCM Delivery Metrics ==="
echo "Note: FCM delivery analytics are available in Firebase Console or via BigQuery export."
echo "Use the Firebase Console > Cloud Messaging > Reports for delivery data."

echo ""
echo "=== Token Validation ==="
# Validate a specific device token
TOKEN="${1:-}"
if [ -n "$TOKEN" ]; then
    iid_api GET "/iid/info/$TOKEN?details=true" \
        | jq '{platform: .platform, app: .application, scope: .rel.topics}'
else
    echo "Provide a device token to validate"
fi

echo ""
echo "=== Topic Management ==="
# Subscribe tokens to a topic
# iid_api POST "/iid/v1:batchAdd" -d '{"to": "/topics/news", "registration_tokens": ["token1"]}'
echo "Use batchAdd/batchRemove IID endpoints for topic management"

Message Health Check

#!/bin/bash
echo "=== Dry Run Message Validation ==="
for platform in "android" "apns" "webpush"; do
    RESULT=$(fcm_api POST "/messages:send" "{
        \"validate_only\": true,
        \"message\": {
            \"topic\": \"test\",
            \"notification\": {\"title\": \"test\", \"body\": \"test\"},
            \"${platform}\": {}
        }
    }")
    STATUS=$(echo "$RESULT" | jq -r 'if .error then .error.status else "VALID" end')
    echo "$platform: $STATUS"
done

echo ""
echo "=== Service Account Permissions ==="
curl -s -H "Authorization: Bearer $FIREBASE_ACCESS_TOKEN" \
    "https://cloudresourcemanager.googleapis.com/v1/projects/${FIREBASE_PROJECT_ID}:testIamPermissions" \
    -d '{"permissions": ["cloudmessaging.messages.create"]}' \
    | jq '.permissions // ["none"]'

Output Format

=== Firebase Project: <name> (<id>) ===
FCM API Status: <healthy|error>

--- Message Validation ---
Android: <valid|error>  APNS: <valid|error>  Web: <valid|error>

--- Notes ---
Delivery analytics: Firebase Console or BigQuery export
Topic management: Use IID batchAdd/batchRemove APIs

Anti-Hallucination Rules

1. NEVER assume resource names — always discover via CLI/API in Phase 1 before referencing in Phase 2.
2. NEVER fabricate metric names or dimensions — verify against the service documentation or --help output.
3. NEVER mix CLI commands between service versions — confirm which version/API you are targeting.
4. ALWAYS use the discovery → verify → analyze chain — every resource referenced must have been discovered first.
5. ALWAYS handle empty results gracefully — an empty response is valid data, not an error to retry.

Counter-Rationalizations

Common Pitfalls

• No list API: FCM does not provide endpoints to list all topics or tokens
• Dry run: Use validate_only: true to test messages without sending
• Token expiry: Device tokens expire and must be refreshed by client apps
• Rate limits: 600 requests/minute for message sending
• v1 API: Always use FCM v1 API, not legacy HTTP API