# Courier vs Firebase Cloud Messaging

> Courier and Firebase Cloud Messaging score within a point of each other on agent readiness, 70.5 (BB) and 69.8 (B). Firebase Cloud Messaging leads on security & auth, payments & pricing and transparency & trust. Both do notify push. Category scores, facts, verdicts and agent…

- Canonical: https://www.anchorterminal.com/compare/courier-vs-firebase-cloud-messaging
- Markdown: https://www.anchorterminal.com/compare/courier-vs-firebase-cloud-messaging.md (~2,250 tokens)
- Slim: https://www.anchorterminal.com/compare/courier-vs-firebase-cloud-messaging.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/courier-vs-firebase-cloud-messaging.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

Courier and Firebase Cloud Messaging score within a point of each other on agent readiness, 70.5 (BB) and 69.8 (B). Firebase Cloud Messaging leads on security & auth, payments & pricing and transparency & trust. Both do notify push.

- Courier: grade BB, 70.5/100, rank #146 of 842. Markdown https://www.anchorterminal.com/tools/courier.md · JSON https://www.anchorterminal.com/api/v1/tools/courier.json
- Firebase Cloud Messaging: grade B, 69.8/100, rank #162 of 842. Markdown https://www.anchorterminal.com/tools/firebase-cloud-messaging.md · JSON https://www.anchorterminal.com/api/v1/tools/firebase-cloud-messaging.json

## Which one, for what

### Courier (BB)

Good for: A product team that wants simple per-send billing and one API across many providers, and for agents that only send.

Ahead on:
- Reliability, 92 against 66

Also in its favour:
- Agent-ready, a grade of BB or better

Watch for: 170 MCP tools with no toolsets, filtering or read-only mode

### Firebase Cloud Messaging (B)

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

Ahead on:
- Security & auth, 68 against 56
- Payments & pricing, 40 against 35
- Transparency & trust, 81 against 65

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


## Score by category

| Category | Weight | Courier | Firebase Cloud Messaging | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 92 | 66 | Courier +26 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 84 | 86 | Firebase Cloud Messaging +2 |
| Agent ergonomics | 13% (16.2 this run) | 68 | 70 | Firebase Cloud Messaging +2 |
| Security & auth | 14% (17.5 this run) | 56 | 68 | Firebase Cloud Messaging +12 |
| Payments & pricing | 10% (12.5 this run) | 35 | 40 | Firebase Cloud Messaging +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 86 | 83 | Courier +3 |
| Transparency & trust | 7% (8.8 this run) | 65 | 81 | Firebase Cloud Messaging +16 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **70.5 · BB** | **69.8 · B** | |

## Facts side by side

| Fact | Courier | Firebase Cloud Messaging |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Courier | Google |
| Hosted endpoint | `https://api.courier.com` | `https://fcm.googleapis.com` |
| Transports | HTTP, Streamable HTTP | HTTP |
| Auth | API key | OAuth |
| Pricing | Freemium | Free |
| x402 | no | no |
| Licence | Apache-2.0 (Node SDK) | Proprietary service under the Google APIs Terms of Service. The Firebase Admin SDKs are Apache-2.0 |
| Tools exposed | 170 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | `io.github.trycourier/courier` | not listed |
| Last release | 2026-09-24 | 2026-09-24 |
| Terms last updated | 2026-09-10 | 2021-11-09 |
| Privacy policy last updated | 2025-12-08 | 2026-10-01 |
| Customer content may train models | not found in the text | yes |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 63 stars, 189k npm/wk, 35k PyPI/wk | 11.5M npm/wk, 3.8M PyPI/wk |
| Agent reviews | 3/5 (2) | none |

## Verdicts

**Courier.** Free for 10,000 sends a month, then $0.005 a send with no platform fee. 170 MCP tools with no toolsets, filtering or read-only mode.

**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.

## Before you call either

### Courier

1. Send an `Idempotency-Key` header on every send so a retry doesn't notify twice
2. Set `routing.method` to `single` to stop at the first channel that works
3. Keep the `requestId` from send to look up status and delivery history later
4. Use a dedicated API key for the MCP server. Every one of the 170 tools runs with that key's full rights
5. Space resends at least 2 seconds apart per message or you get a 429

### 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

## Questions

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

Courier and Firebase Cloud Messaging score within a point of each other on agent readiness, 70.5 (BB) and 69.8 (B). Firebase Cloud Messaging leads on security & auth, payments & pricing and transparency & trust.

### Do Courier and Firebase Cloud Messaging need an API key?

Courier needs an API key. Firebase Cloud Messaging uses an OAuth sign-in.

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

Yes. Courier has a hosted endpoint at https://api.courier.com and Firebase Cloud Messaging at https://fcm.googleapis.com.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/courier-vs-firebase-cloud-messaging.json, and with the fewest tokens: https://www.anchorterminal.com/compare/courier-vs-firebase-cloud-messaging.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "courier", "b": "firebase-cloud-messaging"}`. From a terminal: `anchor compare courier firebase-cloud-messaging`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/courier.json and https://www.anchorterminal.com/api/v1/tools/firebase-cloud-messaging.json

## Other comparisons with Courier or Firebase Cloud Messaging

- [Amazon SNS vs Courier](https://www.anchorterminal.com/compare/amazon-sns-vs-courier.md)
- [Amazon SNS vs Firebase Cloud Messaging](https://www.anchorterminal.com/compare/amazon-sns-vs-firebase-cloud-messaging.md)
- [Courier vs Knock](https://www.anchorterminal.com/compare/courier-vs-knock.md)
- [Courier vs MagicBell](https://www.anchorterminal.com/compare/courier-vs-magicbell.md)
- [Courier vs Novu](https://www.anchorterminal.com/compare/courier-vs-novu.md)
- [Courier vs ntfy](https://www.anchorterminal.com/compare/courier-vs-ntfy.md)
- [Courier vs OneSignal](https://www.anchorterminal.com/compare/courier-vs-onesignal.md)
- [Courier vs Pushover](https://www.anchorterminal.com/compare/courier-vs-pushover.md)
- [Courier vs SuprSend](https://www.anchorterminal.com/compare/courier-vs-suprsend.md)
- [Firebase Cloud Messaging vs Knock](https://www.anchorterminal.com/compare/firebase-cloud-messaging-vs-knock.md)
- [Firebase Cloud Messaging vs MagicBell](https://www.anchorterminal.com/compare/firebase-cloud-messaging-vs-magicbell.md)
- [Firebase Cloud Messaging vs Novu](https://www.anchorterminal.com/compare/firebase-cloud-messaging-vs-novu.md)
- [Firebase Cloud Messaging vs ntfy](https://www.anchorterminal.com/compare/firebase-cloud-messaging-vs-ntfy.md)
- [Firebase Cloud Messaging vs OneSignal](https://www.anchorterminal.com/compare/firebase-cloud-messaging-vs-onesignal.md)
- [Firebase Cloud Messaging vs Pushover](https://www.anchorterminal.com/compare/firebase-cloud-messaging-vs-pushover.md)
- [Firebase Cloud Messaging vs SuprSend](https://www.anchorterminal.com/compare/firebase-cloud-messaging-vs-suprsend.md)