The request names Firebase, which is not directly listed as a product in the sources; the closest match is Google's Firebase Auth tooling, reachable via the Google platform 1. Firebase Cloud Messaging's Data API itself is not documented on any provided source page, so the alternatives below are general cloud and messaging platforms that expose send and data APIs.

A question back: Do you need the Firebase Cloud Messaging Data API for push notifications to mobile or web clients, or a different messaging channel?

1. 1

   Googlegoogle.comfound in code, not yet checked

   Google's Firebase tooling is indexed here through actions such as get_users for retrieving Firebase Auth users by UID or email, and create_project for creating a Firebase project 1. It does not document a Cloud Messaging Data API on this page.

   Website

   official:MCP server · mcp-securityAPI · Travel Partner APISDK · brotlilibrary · zerocopyCLI · googletest+1,236 community tools built for it

   for agents: get_users · Cloud · create_project

2. 2

   Supabasesupabase.comverified and signed

   Supabase offers a custom API call action and a get_user action for Auth records, plus Postgres, Authentication and Realtime services 2, as a Firebase-style backend alternative.

   WebsiteDocsPricingGet started

   official:SDK · @supabase/auth-jslibrary · Supabase CLI ActionCLI · supabasepackage · Supabaserepository · supabase+106 community tools built for it

   for agents: custom_api_call · get_user · javascript

3. 3

   Twiliotwilio.comverified and signed

   Twilio's Programmable Messaging API sends SMS, MMS, RCS and WhatsApp messages through a REST API 4, useful when the need is multichannel messaging rather than push notifications.

   WebsiteDocsPricingGet started

   official:SDK · twiliolibrary · Twilioskill · twilio-sms-send-message+21 community tools built for it

   for agents: api · twilio-send-message · REST

4. 4

   SendGrid Email APIsendgrid.comverified and signed

   SendGrid's Email API sends transactional email and exposes a get_message action for checking the status of sent messages 9.

   WebsiteGet started

   official:API · Email Activity (beta)+12 community tools built for it

   for agents: get_message · custom_api_call · custom_api_call