Best of · Everyday APIs
Best notification APIs for AI agents
The 10 highest-scoring of 12 notification APIs on the Anchor benchmark, with a pick for each need and where each one falls short. Scores come from public evidence, re-checked as vendors change.
- 12 ranked
- 3 agent-ready
- 12 hosted endpoints
- Updated 9 October 2026
Top three
Picks by need
Worked out from the scores, prices and facts, so they change when the research does.
Schema & documentation
SuprSend BB
94/100 on schema & documentation, against 83 for the overall leader.
Maintenance & community
Novu B
92/100 on maintenance & community, against 75 for the overall leader.
The shortlist
| # | Tool | Grade | Best for | Price | Where |
|---|---|---|---|---|---|
| 1 | Amazon SNS Amazon Web Services |
BB 72.8 | 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. | $0.0005 / 1k req | hosted |
| 2 | SuprSend SuprSend |
BB 72.6 | A SaaS team that needs tenant-aware preferences, digests and batching at a mid-range price, and for agents that inspect users and preferences through MCP. | $110 / mo | hosted and local |
| 3 | Courier Courier |
BB 70.5 | A product team that wants simple per-send billing and one API across many providers, and for agents that only send. | Freemium | hosted |
| 4 | Firebase Cloud Messaging |
B 69.8 | The push transport under an app that already holds device registrations, at no charge. | Free | hosted |
| 5 | OneSignal OneSignal |
B 69.3 | A team whose main channel is push to its own mobile or web app and who wants delivery handled without a separate push provider. | $19 / mo | hosted |
| 6 | Knock Knock |
B 66.5 | 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. | $250 / mo | hosted |
| 7 | Novu Novu |
B 64.2 | A team that wants multi-channel user notifications with an Inbox component and the option to self-host. | $30 / mo | hosted |
| 8 | ntfy ntfy |
C 61.5 | An agent that has to reach its own operator or a small team on their phones with no setup. | $6 / mo | hosted |
| 9 | Expo Push Notifications Expo |
C 58.8 | An agent that must push to an app already built with Expo, at no cost and with one call for both platforms. | Free | hosted |
| 10 | MagicBell MagicBell, Inc. |
C 58.8 | A product team that wants an embeddable in-app inbox with push, email, SMS, Slack and Teams behind one broadcast call, and an agent that sends notifications with a project token it was given. | $249 / mo | hosted |
2 more are ranked in the full table.
How to choose
- Channels reached from one callCheck which channels one request reaches, since an agent that needs push and email for the same event should not have to call a separate endpoint for each.
- Digest and delay windowsCheck how digests and delay windows group events, and whether urgent alerts can skip them, because batching can hide time-sensitive messages.
- Preference and opt-out handlingTest an opt-out on one channel and confirm the person still receives the others, because a global switch could silence messages they asked to keep.
- Message log and retentionRead how long the message log is kept and what it records per message, since an agent that has to prove a message was sent needs that record.
How the benchmark tests this category. One event sent to a user across in-app, push and email, with a digest and a preference opt-out. We check what arrives where, the batching, the opt-out and the delivery log.
Each one in detail
Amazon SNS
BB 72.8/100Amazon SNS is AWS's publish and subscribe messaging service. A message published to a topic, or directly to a device or phone number, goes out as mobile push, SMS, plain-text email, HTTPS calls or to SQS queues and Lambda functions.
Verdict 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.
Choose it 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.
Strengths
- IAM identity policies and topic resource policies per action and topic, temporary credentials, and an
AmazonSNSReadOnlyAccessmanaged policy - Published quotas of 30,000 published messages a second per account in US East (N. Virginia) and 300 in the smallest Regions
- First 1,000,000 API requests, 1,000,000 mobile push notifications and 1,000 emails each month are free on standard topics
Weaknesses
- No idempotency token on
Publishto a standard topic. Only FIFO topics deduplicate, over a five-minute window - No user preferences, digests, templates or in-app channel. Email is plain text and each address has to confirm its subscription
- SMS starts in a sandbox with ten verified numbers and a $1 monthly spend quota, raised through an AWS Support case
Price $0.0005 / 1k reqAuth OAuth or keyx402 nohosted
SuprSend
BB 72.6/100Notification workflow API for email, SMS, push, an in-app Inbox, Slack, Microsoft Teams and webhooks, with digests, batching and preferences per user and per tenant.
Verdict MCP tool descriptions say when to use each tool, when not to, and what it changes, with readOnlyHint and destructiveHint set. No rate-limit page or 429 guidance.
Choose it for A SaaS team that needs tenant-aware preferences, digests and batching at a mid-range price, and for agents that inspect users and preferences through MCP.
Strengths
- MCP tool descriptions say when to use each tool, when not to, and what it changes, with readOnlyHint and destructiveHint set
--toolsloads a subset of the 22 built-in tools, and trigger tools register only for the workflows you name- Free plan with 10,000 notifications, no card and unlimited seats
Weaknesses
- No rate-limit page or 429 guidance
- No hosted MCP server, only the local CLI
- Workspace secrets come back in plain text on every management API response
Price $110 / moAuth API keyx402 nohosted and local
Courier
BB 70.5/100Notification API that routes one message to email, SMS, push, an in-app Inbox, Slack, Microsoft Teams and WhatsApp through your own providers, with templates, digests, preferences and journeys.
Verdict 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.
Choose it for A product team that wants simple per-send billing and one API across many providers, and for agents that only send.
Strengths
- Free for 10,000 sends a month, then $0.005 a send with no platform fee
POST /sendhas no request-count rate limit, and the limited endpoints publish their numbers- Idempotency keys replay for 25 hours by default and up to a year
Weaknesses
- 170 MCP tools with no toolsets, filtering or read-only mode
- MCP authentication is a raw API key header with no OAuth or scopes
- Error responses documented only as
messageandtype, with no list of codes
Price FreemiumAuth API keyx402 nohosted
Firebase Cloud Messaging
B 69.8/100Google's push messaging service for Android, Apple and web apps. A server sends notification or data messages to devices, topics or conditions through the HTTP v1 API or the Firebase Admin SDKs.
Verdict 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.
Choose it for The push transport under an app that already holds device registrations, at no charge.
Strengths
- No charge for sending on either Firebase plan, and no billing account needed (https://firebase.google.com/pricing)
- Default quota of 600,000 messages a minute per project, with 429 responses that carry
retry-afterand written backoff guidance - Short-lived OAuth 2.0 tokens with a
firebase.messagingscope, and IAM permissions per action such ascloudmessaging.messages.create
Weaknesses
- Push transport only. No in-app feed, email, SMS, user preferences, digests or templates
- No idempotency key on
messages:send, so a retried request can reach the device twice - One HTTP request per message. Only the Admin SDKs group up to 500 sends in a call
Price FreeAuth OAuthx402 nohosted
OneSignal
B 69.3/100Messaging platform that sends mobile and web push through its own service and adds email, SMS, RCS, in-app messages, Live Activities and journeys.
Verdict Runs push delivery itself, so there's no separate push provider to wire up. Three incidents on the API and SDK endpoints in September 2026.
Choose it for A team whose main channel is push to its own mobile or web app and who wants delivery handled without a separate push provider.
Strengths
- Runs push delivery itself, so there's no separate push provider to wire up
- 429 with Retry-After, two documented backoff recipes and 30-day idempotency keys
- Hosted MCP server with OAuth only, a confirmation flag on send and no delete tools
Weaknesses
- Three incidents on the API and SDK endpoints in September 2026
- MCP server is in open beta and app access may need enabling before most tools work
- Priced per monthly active user and subscriber, which is hard to forecast
Price $19 / moAuth OAuth or keyx402 nohosted
Knock
B 66.5/100Notification workflow API.
Verdict 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.
Choose it 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.
Strengths
- Hosted MCP server with OAuth, six capability toggles and no delete tools
- Idempotency keys on trigger for 24 hours, plus cancellation keys for delayed runs
- Rate limits published in five tiers from 1 to 1,000 requests a second
Weaknesses
- Three incidents hit workflow processing or delivery between 10 July and 31 August 2026
- No SLA, Retry-After header or backoff guidance found
- Service tokens carry the creator's full privileges with no expiry, and skip MCP consent
Price $250 / moAuth OAuth or keyx402 nohosted
Novu
B 64.2/100Open-source infrastructure for application notifications.
Verdict MIT-licensed core, self-hostable, with server and package releases every few weeks (latest 28 September 2026). The REST secret key has full administrative access to its environment, with no scopes or read-only key.
Choose it for A team that wants multi-channel user notifications with an Inbox component and the option to self-host.
Strengths
- MIT-licensed core, self-hostable, with server and package releases every few weeks (latest 28 September 2026)
- Rate limits per plan with RateLimit and Retry-After headers, and a documented backoff pattern
- Errors page with every status code and one JSON error shape, cursor pagination capped at 100
Weaknesses
- The REST secret key has full administrative access to its environment, with no scopes or read-only key
- The MCP server includes delete tools for subscribers, workflows and integrations, with no read-only mode
- Idempotency keys only work once support enables them for your organisation
Price $30 / moAuth OAuth or keyx402 nohosted
ntfy
C 61.5/100Open-source publish-subscribe service for push notifications.
Verdict Publish with one HTTP POST and no account, up to 250 messages a day per IP on ntfy.sh. Unreserved topics on ntfy.sh can be read and written by anyone who knows the name.
Choose it for An agent that has to reach its own operator or a small team on their phones with no setup.
Strengths
- Publish with one HTTP POST and no account, up to 250 messages a day per IP on ntfy.sh
- Apache-2.0 and GPL-2.0 server, six releases between 9 July and 27 August 2026
- Status page with no incidents since 31 March 2026
Weaknesses
- Unreserved topics on ntfy.sh can be read and written by anyone who knows the name
- No idempotency key, so a retried publish arrives twice
- No OpenAPI spec, llms.txt, official MCP server or SDKs
Price $6 / moAuth OAuth or keyx402 nohosted
Expo Push Notifications
C 58.8/100Hosted push service from Expo that takes one HTTPS request and relays it to Apple's APNs and Google's FCM for apps built with Expo. It issues push tickets and receipts, and sending is free.
Verdict A free push relay with a small, well documented HTTP API, published limits of 600 notifications a second and written error codes. Sending needs no credential unless the owner turns on access tokens, there is no idempotency key or SLA, and the status page records three iOS push incidents since 4 August 2026.
Choose it for An agent that must push to an app already built with Expo, at no cost and with one call for both platforms.
Strengths
- One POST to
https://exp.host/--/api/v2/push/sendreaches both APNs and FCM, with up to 100 messages a request - Sending is free, per the push FAQ, and the Free plan costs $0 a month
- Limits are published. 600 notifications a second per project, 100 messages a request, 1,000 receipt IDs a request
Weaknesses
- The send API needs no authentication by default, so anyone holding a push token can send to that device until the owner enables access tokens
- No idempotency key. Expo says a notification may reach Apple or Google more than once, or not at all
- No SLA for the push service, stated in the docs
Price FreeAuth OAuth or keyx402 nohosted
MagicBell
C 58.8/100MagicBell is a hosted notification service that sends one broadcast to users across an in-app inbox, mobile and web push, email, SMS, Slack and Teams. Agents reach it through a REST API, a CLI and typed clients.
Verdict A public OpenAPI 3.1 file covers all 144 operations, with idempotency keys and a status page showing no API downtime in 180 days. No batching or digest step, llms.txt, error code list, SLA or sub-processor list was found, and project tokens carry no scopes.
Choose it for A product team that wants an embeddable in-app inbox with push, email, SMS, Slack and Teams behind one broadcast call, and an agent that sends notifications with a project token it was given.
Strengths
- OpenAPI 3.1 file with 144 operations, published at
/docs/api/openapi.jsonwithout a login Idempotency-Keyheader caches the first response for 24 hours on some endpoints- Status page shows 100 per cent for the API and dashboard over 180 days to 7 October 2026
Weaknesses
- No batching or digest step found. Workflows have four commands (broadcast, wait, pause, abort)
- No llms.txt or Markdown docs, and the OpenAPI file documents no error responses
- Project tokens are project-wide with no scopes or read-only mode
Price $249 / moAuth API keyx402 nohosted
Head to head
- Amazon SNS vs SuprSend BB 72.8 vs BB 72.6
- Amazon SNS vs Courier BB 72.8 vs BB 70.5
- Amazon SNS vs Firebase Cloud Messaging BB 72.8 vs B 69.8
- Amazon SNS vs OneSignal BB 72.8 vs B 69.3
- Courier vs SuprSend BB 70.5 vs BB 72.6
- Firebase Cloud Messaging vs SuprSend B 69.8 vs BB 72.6
- OneSignal vs SuprSend B 69.3 vs BB 72.6
- Courier vs Firebase Cloud Messaging BB 70.5 vs B 69.8
- Courier vs OneSignal BB 70.5 vs B 69.3
- Firebase Cloud Messaging vs OneSignal B 69.8 vs B 69.3
Questions
What are the highest-rated notification APIs for AI agents?
Amazon SNS has the highest benchmark score of the 12 ranked notification APIs, 72.8 (BB). SuprSend is second with 72.6 (BB).
How many notification APIs are agent-ready?
3 of the 12 ranked here grade BB or better, the bar for agent-ready on the Anchor benchmark.
Which notification APIs accept x402 payments?
None of the ranked listings here accepts x402 for its main call yet.
How is this list ranked?
By the Anchor benchmark score out of 100, a weighted mean of the scored categories minus deductions for negative events, from public evidence re-checked as vendors change. Listings cannot pay for a place. The latest assessment behind this page is from 9 October 2026.
How this list is made
The order is the Anchor benchmark score, the same number as on each listing and in the top list. Each listing is graded from public evidence against the benchmark checklist, and the picks above are worked out from those grades, prices and facts. No listing pays for its place, and paid audits or listing help never change a score.
Full ranked table · 66 head-to-head comparisons · Best tools in every category