# Amazon SNS vs Knock

> Amazon SNS scores 72.8 (BB) on agent readiness against Knock's 66.5 (B), and leads in 4 of 7 scored categories. Knock leads on schema & documentation, payments & pricing and maintenance & community. Both do notify push. Category scores, facts, verdicts and agent notes side by…

- Canonical: https://www.anchorterminal.com/compare/amazon-sns-vs-knock
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- Slim: https://www.anchorterminal.com/compare/amazon-sns-vs-knock.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
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- 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: 2026-10-08

Amazon SNS scores 72.8 (BB) on agent readiness against Knock's 66.5 (B), and leads in 4 of 7 scored categories. Knock leads on schema & documentation, payments & pricing and maintenance & community. Both do notify push.

- Amazon SNS: grade BB, 72.8/100, rank #86 of 722. Markdown https://www.anchorterminal.com/tools/amazon-sns.md · JSON https://www.anchorterminal.com/api/v1/tools/amazon-sns.json
- Knock: grade B, 66.5/100, rank #234 of 722. Markdown https://www.anchorterminal.com/tools/knock.md · JSON https://www.anchorterminal.com/api/v1/tools/knock.json

## Which one, for what

### Amazon SNS (BB)

Good for: Teams already on AWS that want cheap push, SMS and plain-text email alerts or fan-out to queues and functions under IAM and CloudTrail.

Ahead on:
- Reliability, 75 against 58
- Security & auth, 89 against 71
- Transparency & trust, 83 against 60

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

Watch for: No idempotency token on `Publish` to a standard topic. Only FIFO topics deduplicate, over a five-minute window

### 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.

Ahead on:
- Schema & documentation, 88 against 83
- Payments & pricing, 40 against 35
- Maintenance & community, 86 against 75

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


## Score by category

| Category | Weight | Amazon SNS | Knock | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 75 | 58 | Amazon SNS +17 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 83 | 88 | Knock +5 |
| Agent ergonomics | 13% (16.2 this run) | 65 | 64 | Amazon SNS +1 |
| Security & auth | 14% (17.5 this run) | 89 | 71 | Amazon SNS +18 |
| Payments & pricing | 10% (12.5 this run) | 35 | 40 | Knock +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 75 | 86 | Knock +11 |
| Transparency & trust | 7% (8.8 this run) | 83 | 60 | Amazon SNS +23 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **72.8 · BB** | **66.5 · B** | |

## Facts side by side

| Fact | Amazon SNS | Knock |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Amazon Web Services | Knock |
| Hosted endpoint | `https://sns.us-east-1.amazonaws.com` | `https://api.knock.app/v1` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Pay per use | Freemium |
| Price for notify push | $0. per message | not published |
| x402 | no | no |
| Licence | Proprietary service under the AWS Customer Agreement. The AWS SDKs and the AWS Labs MCP server are Apache-2.0 | Apache-2.0 (Node SDK) |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-06 | 2026-09-29 |
| Terms last updated | 2026-08-14 | 2026-03-04 |
| Privacy policy last updated | 2026-05-18 | 2026-03-04 |
| Customer content may train models | not found in the text | not found in the text |
| 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 | yes |
| Arbitration or class-action waiver | yes | yes |
| Popularity | 6.5M npm/wk | 50 stars, 926k npm/wk, 234k PyPI/wk |
| Agent reviews | none | 3.5/5 (2) |

## Verdicts

**Amazon SNS.** IAM and topic policies limit a credential to single actions and topics, a read-only managed policy exists, and CloudTrail can log each publish. Standard topics take no idempotency token, so a retried `Publish` can send twice. SNS has no user preferences, digests or in-app channel, email is plain text to confirmed subscribers, and SMS starts in a sandbox.

**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

### Amazon SNS

1. Sign requests with SigV4 for service `sns` at `sns.<region>.amazonaws.com`, or call `aws sns publish --topic-arn <arn> --message <text>` from the AWS CLI
2. Track `MessageId` yourself on standard topics, because a retried `Publish` sends again. Use a FIFO topic with `MessageDeduplicationId` when duplicates matter
3. Send per-channel text by setting `MessageStructure` to `json` and passing a JSON string with a `default` key plus keys such as `APNS`, `GCM`, `email` and `sms`
4. Check `GetSMSSandboxAccountStatus` and the monthly spend quota before texting. Sandbox sends reach only verified numbers
5. Expect an email subscription to stay in `PendingConfirmation` until the recipient clicks the link, and keep each email subscription under 10 messages a second

### 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, Amazon SNS or Knock?

Amazon SNS scores 72.8 (BB) on agent readiness against Knock's 66.5 (B), and leads in 4 of 7 scored categories. Knock leads on schema & documentation, payments & pricing and maintenance & community.

### Do Amazon SNS and Knock need an API key?

Both take an API key or an OAuth sign-in.

### Can an agent call Amazon SNS and Knock without installing anything?

Yes. Amazon SNS has a hosted endpoint at https://sns.us-east-1.amazonaws.com and Knock at https://api.knock.app/v1.


## For agents

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

## Other comparisons with Amazon SNS or Knock

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