Local AWS cloud emulator for integration tests. Run your app with normal AWS clients, stay fully local, and use fakecloud SDKs when your tests need deeper visibility.
39 services. 2,592 operations. 86,327/86,327 Smithy variants pass — true 100% conformance.
fakecloud gives you a local AWS environment that behaves like infrastructure, not a mock. Your app uses the regular AWS SDK, CLI, and IaC tools. Unlike today's LocalStack Community setup, you do not need an account, auth token, or paid plan just to keep core development flows local.
The SDKs make that workflow nicer, not narrower. Start fakecloud, run the code you actually ship, inspect emails/messages/invocations after the fact, and force async AWS-style behavior to happen on demand.
Real APIs for your app, purpose-built tooling for your tests.
Use normal AWS clients against localhost, then verify the effects with fakecloud instead of stitching together polling, fixtures, or private test hooks.
TypeScript, Python, Go, PHP, Java, and Rust SDKs wrap the /_fakecloud/* endpoints for resets, assertions, and manual control of async processors after your app has already used the normal AWS APIs.
S3, SQS, SNS, EventBridge, EventBridge Scheduler, Lambda, DynamoDB, IAM, STS, SSM, Secrets Manager, CloudWatch Logs, CloudWatch (Metrics & Alarms), KMS, CloudFormation, SES, Cognito User Pools, Cognito Identity, Kinesis, Firehose, RDS, ElastiCache, Step Functions, API Gateway v1 (REST), API Gateway v2 (HTTP), Bedrock, Bedrock Agent, Bedrock Agent Runtime, Bedrock Runtime, ECR, ECS, Elastic Load Balancing v2, CloudFront, Route 53, WAF v2, Application Auto Scaling, Athena, ACM, and Glue.
True 100% conformance across all 2,592 implemented API operations: 86,327/86,327 Smithy-model-generated test variants pass on every commit, backed by end-to-end tests against the official AWS SDKs.
30+ service-to-service integrations: S3 notifications, SNS fanout, EventBridge targets, DynamoDB Streams, CloudWatch Logs subscriptions, Cognito triggers, Step Functions task integrations, API Gateway → Lambda, and more — all exercise real service interactions.
Run a single binary or Docker image, use any dummy credentials, and keep the whole workflow local without signing in to someone else's platform.
Keep using the AWS SDK in your app. Use fakecloud SDKs when your tests need visibility and control on top of the emulator itself.
npm install fakecloudInspect SES emails, SNS messages, SQS queues, Lambda invocations, Cognito confirmation codes, and more.
View on npmpip install fakecloudAsync and sync clients for pytest or app-level integration tests, with the same introspection and simulation coverage.
View on PyPIgo get github.com/faiscadev/fakecloud/sdks/goContext-friendly helpers for resets, event history, SES inbound simulation, and the rest of the fakecloud test surface.
View on pkg.go.devcargo add fakecloud-sdkNative Rust client for tests that need resets, state inspection, and direct access to the fakecloud introspection surface.
View on crates.ioStart fakecloud, point your AWS client at localhost, then assert what happened.
If you want a fully local workflow with real AWS APIs and no account requirement, fakecloud is built for that path. The SDKs are an extra testing advantage, not a replacement for that positioning.
| fakecloud | LocalStack Community | |
|---|---|---|
| License | AGPL-3.0 | Proprietary |
| Auth required | No | Yes (account + token) |
| Commercial use | Free | Paid plans only |
| Docker required | No (standalone binary) | Yes |
| Startup time | ~300ms | ~3s |
| Idle memory | ~10 MiB | ~150 MiB |
| Install size | ~19 MB binary | ~1 GB Docker image |
| AWS services | 39 at true 100% conformance | 30+ (paid-only past Community) |
| Test assertion SDKs | TypeScript, Python, Go, PHP, Java, Rust | Python, Java |
| Cognito User Pools | 122 operations | Paid only |
| SES v2 | 110 operations | Paid only |
| SES inbound email | Real receipt rule actions | Stored but never executed |
| RDS | 163 operations, PostgreSQL/MySQL/MariaDB via Docker, PostgreSQL aws_lambda extension | Paid only |
| ElastiCache | 75 operations, Redis and Valkey via Docker | Paid only |
| API Gateway v2 | 103 operations, HTTP APIs + developer portals + JWT/Lambda authorizers | Paid only |
| Bedrock | 214 operations across 4 APIs (Bedrock + Bedrock Runtime + Bedrock Agent + Bedrock Agent Runtime) | Not available |
Every implemented API is covered by conformance and behavioral testing, with the service mix tuned for local development and integration tests.