Sentinel
Sentinel: Affordable API checks with JSON assertions, multi-region monitoring, and MCP access. Ranked #14 of 27 in API Monitoring Tools by our editors (8.1/10); pricing: Free plan · 14-day trial; best for affordable API checks with MCP access.
At a glance
- Editor score8.1 / 10
- PricingFree plan · 14-day trial
- Best forAffordable API checks with MCP access
- Free planYes
- Paid from$144/yr
- Response assertionsYes
- Facts checked7 Nov 2026
Where it wins
- JSON-path assertions validate API response fields and values.
- Checks run from 15 global regions across six continents with incident creation.
- MCP, REST API, Terraform, webhooks, and major alert integrations.
Where it doesn't
- The Free plan limits monitoring to 10 monitors and 5-minute checks.
- SMS outage alerts are limited to the United States and Canada.
- The product was founded in 2024, offering a shorter maturity history.
Our verdict on Sentinel
Sentinel is a cloud monitoring service for agencies, freelance developers, and SaaS teams that need recurring API and health-check validation. It sends requests to API and health-check endpoints, checks JSON response fields and values, and alerts teams when assertions fail. Its wider monitoring coverage includes uptime, SSL certificates, DNS records, domain expiration, keywords, ICMP ping, TCP ports, and heartbeat or cron jobs. Web, macOS, and API access support browser-based monitoring, a native menu bar app, and programmatic workflows.
According to the vendor's pricing page, Sentinel has a Free plan with up to 10 monitors, 5-minute checks, JSON/API checks, one public status page, email and Discord notifications, and read-only API and MCP access. Starter costs $14 per month billed monthly, or $144 per year billed annually, for up to 25 endpoints, 1-minute checks, heartbeat and cron monitoring, Slack and Teams alerts, and five client status pages. Pro costs $29 per month billed monthly, or $288 per year billed annually, and adds up to 100 endpoints, Lighthouse audits, full API, Terraform and provisioning access, signed webhooks, AI assistants that act, and teams with up to five members. Business costs $79 per month billed monthly, or $768 per year billed annually, with up to 300 endpoints, 15-second checks, PagerDuty, unlimited teams and members, unlimited status pages, and priority support.
The standout capability is response-aware API monitoring: custom GET, POST, PUT, PATCH, DELETE, HEAD, and OPTIONS requests can be paired with JSON path assertions and multi-region checks. Incident creation, status pages, and alerts through email, SMS, Slack, Discord, Teams, and webhooks extend those checks into operational workflows. Integrations with GitHub, Terraform, command line tools, and MCP access suit teams that want monitoring connected to development or AI-assisted processes. Sentinel fits buyers seeking low-cost API validation and broad endpoint coverage; teams needing more than 300 endpoints or a faster interval than 15 seconds should consider alternatives.
Your product? Our editors can test Sentinel in depth and publish a review, labelled as paid · from $149/mo →
Sentinel pricing
All 4 Sentinel plans and prices →
Sentinel fact sheet
| Free plan | Yes |
|---|---|
| Paid from | $144/yr |
| Check frequency | 15 sec |
| Response assertions | Yes |
| Multi-region checks | Yes |
| Private locations | Not verified |
| Monitor limit | 25 monitors |
| Incident workflows | Yes |
| Free trial | 14 days · card required |
| Money-back guarantee | 30 days |
| Deployment | Cloud, Desktop |
| Platforms | Web, macOS |
| Support | Docs |
| Built for | Solo, Small business, Mid-market, Enterprise (editorial estimate) |
| Integrations | 9 integrations: Email, SMS, Slack, Discord, Microsoft Teams, Webhooks … See all → |
| Pricing | Free plan · 14-day trial (source) |
| Website | sentinel.rootstuff.io |
| Facts checked | 7 Nov 2026 |
Sentinel integrations
Sentinel lists 9 integrations on its own site.
- SMS
- Slack
- Discord
- Microsoft Teams
- Webhooks
- PagerDuty
- REST API
- MCP
See all Sentinel integrations →
Alternatives to Sentinel
- ObserveOne API MonitoringA flexible API monitoring service with strong automation, alerting, and self-hosted options.9.4
- APIContextDeep API and workflow coverage with a strong free tier and higher entry pricing.9.3
- Site24x7 API MonitoringA broad API monitoring option with multi-protocol checks, private locations, and mobile access.9.2
See all Sentinel alternatives →
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Reviewed by iTechGuides Editors · Editorial team · Updated Nov 2026
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