Cost Explorer (`ce:*`)

Protocol: JSON 1.1 Header: X-Amz-Target: AWSInsightsIndexService.<Action> Endpoint prefix: ce

Floci synthesizes Cost Explorer responses from its own resource state, multiplied by the bundled AWS Pricing snapshot served by the Pricing service. Costs reflect what's running in Floci right now, so any test that mutates resources (e.g. creates a bucket, runs an instance) sees those changes in the next GetCostAndUsage call.

Supported Actions

Action	Description
`GetCostAndUsage`	Full `TimePeriod` / `Granularity` / `Filter` / `GroupBy` / `Metrics` support
`GetCostAndUsageWithResources`	Same shape as `GetCostAndUsage`; for resource-level breakdown, group by `Type=DIMENSION,Key=RESOURCE_ID`
`GetDimensionValues`	Returns dimension values present in the synthesized data set
`GetTags`	Returns tag keys / values across enumerated resources
`GetReservationCoverage`	Stub; returns zeroed totals; full RI math lands in a follow-up PR
`GetReservationUtilization`	Stub; returns zeroed totals
`GetSavingsPlansCoverage`	Stub; returns empty list
`GetSavingsPlansUtilization`	Stub; returns zeroed totals
`GetCostCategories`	Stub; returns empty list (cost-category management not yet emulated)
`CreateAnomalyMonitor`	Store a dimensional or custom monitor with optional resource tags
`GetAnomalyMonitors`	List account-scoped monitors with ARN filters and pagination
`UpdateAnomalyMonitor`	Update a monitor's name
`DeleteAnomalyMonitor`	Delete a monitor without deleting subscriptions
`CreateAnomalySubscription`	Store subscriber, frequency, monitor, and threshold configuration
`GetAnomalySubscriptions`	List subscriptions with ARN or monitor filters and pagination
`UpdateAnomalySubscription`	Update supplied settings while preserving omitted fields
`DeleteAnomalySubscription`	Delete a subscription
`ListTagsForResource`	Read monitor or subscription tags
`TagResource`	Add or replace monitor or subscription tags
`UntagResource`	Remove monitor or subscription tag keys

Cost anomaly configuration

Monitors and subscriptions support creation, listing, updates, deletion, and resource tags. They are global within the calling account: requests signed for different regions see the same resources, while another account cannot read or modify them. Definitions and tags use Floci's configured storage and survive restarts in persistent storage modes.

DIMENSIONAL monitors support SERVICE, LINKED_ACCOUNT, TAG, and COST_CATEGORY. Tag and cost-category monitors provide a key in MonitorSpecification; CUSTOM monitors provide linked-account, tag, or cost-category values. MonitorSpecification is a JSON object, including when the caller's configuration tool represents it internally as a JSON string.

Subscriptions support DAILY or WEEKLY email configuration and IMMEDIATE SNS configuration. Updates preserve omitted fields and reject invalid changes before writing. The deprecated Threshold input is accepted as an absolute-cost shorthand; reads return its normalized ThresholdExpression. Monitor names are labels, not idempotency keys.

GetAnomalyMonitors and GetAnomalySubscriptions accept their ARN-list filters, MaxResults, and NextPageToken; subscriptions also support a MonitorArn filter. Tags are managed through ResourceArn, ResourceTags, and ResourceTagKeys, and are not embedded in the resource definitions returned by the list APIs.

Deleting a monitor leaves subscriptions intact and editable. In this emulator, their saved monitor ARN lists remain unchanged until explicitly updated. Monitor evaluation, anomaly generation, email confirmation, and email/SNS notification delivery are not emulated. Floci does not synthesize subscriber confirmation status or a monitor's last evaluation date. Organizations management-account eligibility is not enforced for the additional dimensional monitor types.

For example, create a monitor and a daily subscription against the local endpoint:

MONITOR_ARN=$(aws ce create-anomaly-monitor --endpoint-url http://localhost:4566 \
  --anomaly-monitor '{"MonitorName":"services","MonitorType":"DIMENSIONAL","MonitorDimension":"SERVICE"}' \
  --resource-tags Key=Environment,Value=development --query MonitorArn --output text)

aws ce create-anomaly-subscription --endpoint-url http://localhost:4566 \
  --anomaly-subscription "{\"SubscriptionName\":\"daily-alerts\",\"Frequency\":\"DAILY\",\"MonitorArnList\":[\"$MONITOR_ARN\"],\"Subscribers\":[{\"Address\":\"alerts@example.com\",\"Type\":\"EMAIL\"}],\"ThresholdExpression\":{\"Dimensions\":{\"Key\":\"ANOMALY_TOTAL_IMPACT_ABSOLUTE\",\"Values\":[\"100\"],\"MatchOptions\":[\"GREATER_THAN_OR_EQUAL\"]}}}"

Cost synthesis model

Each Floci service that wants to participate in cost reporting ships a {@code @ApplicationScoped} bean implementing ResourceUsageEnumerator (in core/common/). Cost Explorer auto-discovers these via CDI — adding a new service with cost data needs zero changes to CostExplorerService.

The bundled enumerators cover:

Service	Priced unit	Source
`AmazonEC2`	`BoxUsage:<instanceType>` × hours	`Ec2Service.describeInstances`
`AmazonS3`	`TimedStorage-Standard` × GB-month	`S3Service.listBuckets` + `listObjects`
`AWSLambda`	`AWS-Lambda-Requests` (zero quantity, catalog only)	`LambdaService.listFunctions`
Other Floci services (DDB, SQS, SNS, …)	catalog only, zero quantity	`UnpricedServicesEnumerator`

Unpriced services emit zero-quantity catalog rows so they remain visible in GetDimensionValues SERVICE responses without contributing billed cost.

`RECORD_TYPE` semantics

GROUP_BY=RECORD_TYPE distinguishes:

Record type	When emitted
`Usage`	All synthesized usage rows (always present)
`Credit`	When `FLOCI_SERVICES_CE_CREDIT_USD_MONTHLY > 0` (see below)
`Tax` / `Refund` / `DiscountedUsage` / `SavingsPlan*`	Reserved for future PRs; not currently emitted

Synthetic credit injection

Set FLOCI_SERVICES_CE_CREDIT_USD_MONTHLY (default 0.0) to emit a monthly Credit row that offsets min(creditUsd, monthly Usage cost). Useful for exercising any code path that computes net cost (gross usage − credits) without having to build credit fixtures by hand.

floci:
  services:
    ce:
      credit-usd-monthly: 100.0

Configuration

Variable	Default	Description
`FLOCI_SERVICES_CE_ENABLED`	`true`	Enable or disable the service
`FLOCI_SERVICES_CE_CREDIT_USD_MONTHLY`	`0.0`	Synthetic monthly credit, applied as a `Credit` `RECORD_TYPE` row

Examples

export AWS_ENDPOINT_URL=http://localhost:4566
export AWS_DEFAULT_REGION=us-east-1
export AWS_ACCESS_KEY_ID=test
export AWS_SECRET_ACCESS_KEY=test

aws ce get-cost-and-usage \
  --time-period Start=2026-01-01,End=2026-02-01 \
  --granularity MONTHLY \
  --metrics UnblendedCost \
  --group-by Type=DIMENSION,Key=SERVICE

aws ce get-dimension-values \
  --time-period Start=2026-01-01,End=2026-02-01 \
  --dimension SERVICE

import boto3

ce = boto3.client(
    "ce",
    endpoint_url="http://localhost:4566",
    region_name="us-east-1",
)

resp = ce.get_cost_and_usage(
    TimePeriod={"Start": "2026-01-01", "End": "2026-02-01"},
    Granularity="MONTHLY",
    Metrics=["UnblendedCost"],
    GroupBy=[{"Type": "DIMENSION", "Key": "SERVICE"}],
    Filter={
        "Not": {"Dimensions": {"Key": "SERVICE", "Values": ["AmazonRDS"]}}
    },
)
for result in resp["ResultsByTime"]:
    for group in result["Groups"]:
        print(group["Keys"], group["Metrics"]["UnblendedCost"]["Amount"])

Out of Scope

Forecasting (GetCostForecast, GetUsageForecast).
Right-sizing recommendations (GetRightsizingRecommendation).
Anomaly evaluation and results (GetAnomalies), email confirmation, and email/SNS delivery.
Real Reservation / Savings Plan utilization math — currently zeroed stubs.
Cost category management (CreateCostCategoryDefinition / *Definition / ListCostCategoryDefinitions).
Resource-level granularity beyond what GetCostAndUsageWithResources exposes today.

Cost Explorer (ce:*)