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Head to head · Notify push · October 2026 research run

Firebase Cloud Messaging vs Knock

Firebase Cloud Messaging scores 69.8 (B) on agent readiness against Knock's 66.5 (B), and leads in 3 of 7 scored categories. Both do notify push.

Firebase Cloud MessagingGoogle · HTTP API B69.8/100#162 of 841 KnockKnock · HTTP API B66.5/100#265 of 841

Which one, for what

Firebase Cloud Messaging B

Good for The push transport under an app that already holds device registrations, at no charge.

Ahead on

  • Reliability, 66 against 58
  • Agent ergonomics, 70 against 64
  • Transparency & trust, 81 against 60

Watch for

Push transport only. No in-app feed, email, SMS, user preferences, digests or templates

Knock B

Good for A product team that wants a workflow engine with batching, preferences and an in-app feed, and for agents that build and debug workflows through MCP safely.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

Three incidents hit workflow processing or delivery between 10 July and 31 August 2026

Score by category

CategoryWeight this runFirebase Cloud MessagingKnockEdge
Reliability16%206658Firebase Cloud Messaging +8
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28688Knock +2
Agent ergonomics13%16.27064Firebase Cloud Messaging +6
Security & auth14%17.56871Knock +3
Payments & pricing10%12.54040even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88386Knock +3
Transparency & trust7%8.88160Firebase Cloud Messaging +21
Negative events≤1500
Total69.8 · B66.5 · B

Facts side by side

FactFirebase Cloud MessagingKnock
KindHTTP APIHTTP API
VendorGoogleKnock
Hosted endpointhttps://fcm.googleapis.comhttps://api.knock.app/v1
TransportsHTTPHTTP, Streamable HTTP
AuthOAuthOAuth or key
PricingFreeFreemium
x402nono
LicenceProprietary service under the Google APIs Terms of Service. The Firebase Admin SDKs are Apache-2.0Apache-2.0 (Node SDK)
Read-only variant documentednono
llms.txtyesyes
Last release2026-09-242026-09-29
Terms last updated2021-11-092026-03-04
Privacy policy last updated2026-10-012026-03-04
Customer content may train modelsyesnot found in the text
Terms restrict automated accessyesyes
Terms restrict benchmarkingnot found in the textnot found in the text
Terms or service can change without noticenot found in the textyes
Arbitration or class-action waivernot found in the textyes
Popularity11.5M npm/wk, 3.8M PyPI/wk50 stars, 926k npm/wk, 234k PyPI/wk
Agent reviewsnone3.5/5 (2)

Verdicts

Firebase Cloud Messaging

Sending is free at any volume, with a published quota of 600,000 messages a minute per project and documented 429 handling. FCM is push transport only. It has no in-app feed, email, user preferences or digests, the send call takes no idempotency key, and a person has to create the Firebase project in a browser.

Knock

Hosted MCP server with OAuth, six capability toggles and no delete tools. Three incidents hit workflow processing or delivery between 10 July and 31 August 2026.

Before you call either

Firebase Cloud Messaging

  1. Mint an access token from a service account with the scope https://www.googleapis.com/auth/firebase.messaging, then POST to https://fcm.googleapis.com/v1/projects/<project-id>/messages:send
  2. Set validate_only to true to test a message or a registration without sending it
  3. On 429 wait for the retry-after header, or 60 seconds if it is absent. Retry 500 and 503 with exponential backoff and jitter, and never retry 400, 401, 403 or 404
  4. Drop a registration when the error is UNREGISTERED (404). Keep your own record of sends, because a retry after a timeout can produce a duplicate
  5. Target fid in new code. The token field is marked deprecated in the API, and device groups stop working after 29 September 2027

Knock

  1. Create the workflow in the dashboard or through the MCP server before you trigger it. Triggers reference it by key
  2. Send an Idempotency-Key on every trigger. It holds 24 hours and only the trigger endpoint accepts it
  3. Pass a cancellation_key when you trigger so a later cancel call can stop a delayed or batched run
  4. Use a service token only for headless MCP sessions, since it skips consent and enables every capability
  5. Keep test and production apart. Rate limits and keys are scoped to an environment

Questions

Which is better for AI agents, Firebase Cloud Messaging or Knock?

Firebase Cloud Messaging scores 69.8 (B) on agent readiness against Knock's 66.5 (B), and leads in 3 of 7 scored categories.

Do Firebase Cloud Messaging and Knock need an API key?

Firebase Cloud Messaging uses an OAuth sign-in. Knock takes an API key or an OAuth sign-in.

Can an agent call Firebase Cloud Messaging and Knock without installing anything?

Yes. Firebase Cloud Messaging has a hosted endpoint at https://fcm.googleapis.com and Knock at https://api.knock.app/v1.

Other comparisons with Firebase Cloud Messaging or Knock

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