How it works
From a read-only role to your first recommendation in minutes.
No agents, no sidecars, and nothing installed in your VPC. Reserver works through AWS APIs alone, starting from a role you control and can revoke at any time.
Step 01: Connect
Grant a role that can look, not touch.
An owner or admin clicks Connect in the app. Reserver opens a pre-filled AWS quick-create-stack link, so nothing gets hand-typed. Accepting the link creates a read-only role. Its trust policy requires an ExternalId drawn from the stack's own GUID. That stops anyone else from assuming the role, even if they learn its ARN. The stack then registers itself with Reserver. The account appears in your org with no extra step.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"ec2:DescribeRegions",
"ec2:DescribeInstances",
"ec2:DescribeReservedInstances",
"rds:DescribeDBInstances",
"rds:DescribeReservedDBInstances",
"elasticache:DescribeCacheClusters",
"elasticache:DescribeReservedCacheNodes",
"elasticache:ListTagsForResource",
"cloudwatch:GetMetricData"
],
"Resource": "*"
}]
}- Nine named read-only calls: eight Describe and List calls across EC2, RDS, and ElastiCache, plus CloudWatch GetMetricData for utilization sampling. No service-wide wildcards.
- Single-use, 60 minutes: the install link works once and expires an hour after it's minted.
- Manual fallback: already have a role that matches the template? Paste the role ARN and external ID by hand instead.
- One stack, one account: each stack connects one AWS account today. One-stack AWS Organizations discovery will connect every member account at once.next · M6
Step 02: Scan
Take inventory of the whole fleet.
Reserver scans your accounts and builds two lists. The first list is what's running: every RDS instance, ElastiCache cluster, and EC2 instance. Each one carries its class, family, region, AZ, engine, and platform. The second list is what you own: every reservation, with its term, payment option, and expiry date.
- RDS: instances, clusters, and Multi-AZ topology.
- ElastiCache: Redis and Memcached node fleets.
- EC2: instances, platform, and tenancy details.
- Every six hours: a scan runs automatically on that cadence, so the picture never goes stale.
- Or right now: an admin can start a scan by hand from the Connections page at any time.
Step 03: Match
Match every reservation. Find every gap.
Reservations are matched to running instances the way AWS billing applies them. The match checks service, class or family, region or AZ, and engine. Size flexibility is included. What's left is your true coverage position.
- Covered: a reservation matched to a live instance.
- Gap: a steady workload paying the on-demand rate.
- Idle: a reservation owned, with nothing using it.
- Expiring: coverage about to lapse with no warning.
Step 04: Recommend, then act
Reserver forms an opinion. You decide how far it runs.
Every gap becomes a concrete recommendation, with the math shown. Today, you buy it yourself, in the AWS console. Some of this is live. The rest is on the roadmap.
Live today
- A recommendation for every gap: exact instance class, term, payment option, break-even date, and dollars saved per year.
- Rightsizing caution: flags a recommendation built on capacity that never got busy.
- Old-generation flags: names the current-generation family that replaces an old one.
- Expiry radar: flags a reservation about to lapse before it does.
- You buy it: in the AWS console, today. Reserver never buys anything on its own.
On the roadmap
- Notifications: a recommendation, an expiring term, or a weekly digest will reach your channel: email, Slack, or SMS.building · M3
- One-click purchase: buying a recommendation will take one click, once the purchase role ships.building · M4
- Renewal autopilot: an expiring reservation will renew itself on the terms you set.building · M5
- Scheduled purchases: an accepted recommendation will buy itself on the schedule you choose.building · M5
- Age-based rules: an instance older than the age you set will get a recommendation to reserve it, on its own.building · M5
- Approval flows: a human sign-off will gate a purchase before it runs.building · M4
- Purchase ledger: every purchase will be logged: who approved it, what it cost, and why.building · M4
Every fleet size
The same four steps at every size.
One stack and one scan. Watch costs $0 and covers 1 AWS account.
One stack per account. Autopilot costs $149 a month and covers up to 5 AWS accounts. Invite teammates as read-only members.
One stack per account today. Scale costs $499 a month and covers unlimited AWS accounts in one coverage map.
Today, each account gets its own stack. One-stack AWS Organizations discoverynext · M6 will connect every member account at once.
Why the six-hour cadence matters
What a missed renewal costs, next to what this costs.
These figures are illustrative, for one sample instance. A reservation that lapses for six hours costs about $3.36 in on-demand overage. Left for three days, the same lapse costs about $40.32. Both figures are per instance, so they grow with every instance the reservation covered. Watch costs $0 and shows an expiring term on the expiry radar before it lapses. Autopilot costs $149 a month and covers up to 5 AWS accounts. The default six-hour scan catches a slip on the same day. A quarterly review would find it weeks later.
See the full math on the renewal cost calculator and thesavings estimator.
Questions
How it works, straight answers.
How long does connecting take?
A few minutes. Accept the quick-create stack, and the role exists. The next scan runs on the six-hour cycle. You can also start one by hand from the Connections page.
What can the role read, and what can it do?
Nine named read-only calls: eight Describe and List calls across EC2, RDS, and ElastiCache, plus CloudWatch GetMetricData. The CloudWatch call samples utilization. The role cannot start, stop, modify, or delete anything.
How do I disconnect?
Delete the role in your AWS console. Access ends immediately. No support ticket, no waiting on us.
How often does Reserver scan?
Every six hours by default. An admin can also start a scan by hand from the Connections page at any time.
Can I connect a whole AWS Organization?
Not yet. One stack connects one account today. Discovering every account under one AWS Organization from a single connection is on the roadmap.
Does Reserver buy anything for me?
No, not today. You buy every recommendation yourself, in the AWS console. One-click purchasing is on the roadmap.
Prefer to see it? Take the product tour →
Stop overpaying for a steady fleet.
Reserver is in early access. Join the list, and we will onboard you when we have capacity. Your first recommendation lands within minutes of connecting.