{"generated_at":"2026-11-12T18:35:23.044Z","source":{"name":"Hacker News public API","url":"https://github.com/HackerNews/API","attribution":"Stories and comments are public Hacker News submissions by their respective authors. HackerHub is an independent reader, not affiliated with Y Combinator.","content_is_untrusted":true},"story_id":50456631,"hn_url":"https://news.ycombinator.com/item?id=50456631","total_comments":261,"returned":20,"scope":"Up to the requested number of top-level comments in Hacker News ranked order. Deleted comments are omitted. Nested replies are not fetched; this is not the complete thread.","comments":[{"id":50456723,"author":"CharlieDigital","created_at":"2026-11-11T18:27:14.000Z","text":"Skeptical of using because it's not clear whether this was just an exercise or a real product they are going to ship and maintain.\nFloci[0] has been great for me. Use the Testcontainers[1], too.\nBonus: works for GCP and Azure, too (so far have only used in limited capacity, though).\n[0] https://floci.io/\n[1] https://testcontainers.com/modules/floci/","parent_id":50456631,"replies_count":6,"hn_url":"https://news.ycombinator.com/item?id=50456723"},{"id":50459920,"author":"scriptsmith","created_at":"2026-11-11T22:45:33.000Z","text":"From the security page [0]\n> Don’t use the emulator to test the following:\n> - IAM policies and permissions boundaries\n> - Resource-based policies, such as bucket policies\n> - AWS KMS key policies\n> - Access across AWS accounts or across AWS Regions\n> - Any other security control\n> Some services in the emulator evaluate IAM policies for IAM users and roles that you create in the emulator, but not the same way as AWS. The emulator never denies a request signed with its own key. It doesn’t check AWS KMS key policies or Amazon S3 bucket policies. It also doesn’t support calls across accounts or Regions. So a request that AWS denies might succeed in the emulator. A request that AWS allows might fail.\nThis is a shame because I'd love for the official AWS product to be better than e.g. ministack and localstack on this, which will go some of the distance. I think because the agents were only building on the public API surface, it's hard to build this part. But they should've tried and let the agents read whatever policy engines AWS has. Or maybe it's a way to prevent someone from trivially running aws-emulator as AWSaaS?\n[0] https://docs.aws.amazon.com/emulator/latest/userguide/securi...","parent_id":50456631,"replies_count":4,"hn_url":"https://news.ycombinator.com/item?id=50459920"},{"id":50458860,"author":"wg0","created_at":"2026-11-11T21:20:51.000Z","text":"Say whatever but without AI and agents, no one in AWS would have thought of building this given the huge amount of services they have. Humanly, possible but very very costly. Not saying has not happened before but fakecloud and localstack etc? That moat is gone.\nI am shocked TBH that this is the new normal. Agents writing code in one of the most difficult to use languages. And ugly as well TBH, it pokes into your eyes. Subjective I know but it is a horrible language for humans.","parent_id":50456631,"replies_count":5,"hn_url":"https://news.ycombinator.com/item?id=50458860"},{"id":50457202,"author":"morelandjs","created_at":"2026-11-11T19:10:26.000Z","text":"Fellow Amazonian here. Want to say that I’m grateful you built this and it has tremendous value if pulled off well and properly maintained.\nAgentic development is all about closing off a system as much possible, then mocking up or simulating any inputs or dependencies that cannot be closed off. At that point, you let Claude crawl over the system and do its thing.\nThis inevitably runs into problems with infrastructure and any tools that help mock up those interfaces will be tremendously valuable. Thank you!","parent_id":50456631,"replies_count":0,"hn_url":"https://news.ycombinator.com/item?id=50457202"},{"id":50464245,"author":"fergie","created_at":"2026-11-12T07:52:07.000Z","text":"I feel like we don't talk enough about the massive problem of creating local test environments for AWS deployments.\nAn actual AWS supported env that you can run on your local machine would be super useful, even if it just had a subset comprising the most popular services.","parent_id":50456631,"replies_count":0,"hn_url":"https://news.ycombinator.com/item?id=50464245"},{"id":50458542,"author":"Shakahs","created_at":"2026-11-11T20:55:19.000Z","text":"AWS already models all their services with Smithy, the specification language they created. Their API clients are all generated from Smithy, and the emulator seems to have been built using the Smithy specs and comprehensive integration testing against the real APIs. Using the spec ensures they hit every variant and optional field of every endpoint, unlike Floci and Ministack that only implement the more commonly used ones.\nhttps://github.com/aws/api-models-aws\nhttps://github.com/smithy-lang/smithy","parent_id":50456631,"replies_count":1,"hn_url":"https://news.ycombinator.com/item?id=50458542"},{"id":50457408,"author":"Waterluvian","created_at":"2026-11-11T19:29:08.000Z","text":"If I understand this correctly, it means I can point my entire CDK project to the emulator and test a `cdk deploy`?\nI'm curious just how realistic the \"internal\" behaviour is emulated. It's been a while (since I got my stack working and I just don't like touching it now...), but I recall it being a real pain that sometimes odd, sometimes inconsistent things happened with setup and teardown (even through Terraform), which led to long timeouts if you did things in the wrong (but seemingly valid) order.","parent_id":50456631,"replies_count":2,"hn_url":"https://news.ycombinator.com/item?id=50457408"},{"id":50462127,"author":"MiroslavPokorny","created_at":"2026-11-12T02:05:18.000Z","text":"> At least 100 GB of free disk for target/. The workspace has one crate per AWS service, so a debug build of everything is large, and it grows as services are added.\n100GB !??!?!","parent_id":50456631,"replies_count":0,"hn_url":"https://news.ycombinator.com/item?id=50462127"},{"id":50465971,"author":"pprotas","created_at":"2026-11-12T12:05:09.000Z","text":"Tried it out, this does not seem to work well. A codebase that runs fine on MiniStack could not be emulated with this official AWS emulator.\nSpecifically it does not support certain SFN fields (like `Assign`) and Lambda Python code was not fully supported, so SFNs and Lambdas did not work and the test had to stop there.","parent_id":50456631,"replies_count":0,"hn_url":"https://news.ycombinator.com/item?id=50465971"},{"id":50457726,"author":"jbmchuck","created_at":"2026-11-11T19:51:11.000Z","text":"AFAICT there isn't a quick way to reset state other than restarting the process - in other words it probably isn't a drop in replacement for https://github.com/getmoto/moto for running tons of tests where the state of the mocked AWS system needs to be reset after each test. Hopefully they will implement a quick reset functionality; multiple accounts and full org APIs emulation would be nice too.","parent_id":50456631,"replies_count":1,"hn_url":"https://news.ycombinator.com/item?id=50457726"},{"id":50456656,"author":"super_linear","created_at":"2026-11-11T18:22:45.000Z","text":"Related to this post: https://www.aboutamazon.com/news/aws/how-autonomous-ai-agent...","parent_id":50456631,"replies_count":1,"hn_url":"https://news.ycombinator.com/item?id=50456656"},{"id":50457756,"author":"schonfinkel","created_at":"2026-11-11T19:52:56.000Z","text":"What makes this any different than fakecloud?\nhttps://github.com/faiscadev/fakecloud\nI had a good time using its SDK inside my integration tests. I'll give a couple months before even moving to this because it's weird how similar both projects look like.\nEDIT: After checking AWS's project I'd say stay away from it, looks heavily vibe slopped.","parent_id":50456631,"replies_count":2,"hn_url":"https://news.ycombinator.com/item?id=50457756"},{"id":50466396,"author":"mooreds","created_at":"2026-11-12T12:50:16.000Z","text":"What this means:\nIf you have a product that has APIs and can be verified, anyone can copy the APIs and the features. By the way, you absolutely want to offer APIs so your product can be used by agents.\nThis means you need to compete on aspects other than features.\nJust because you can emulate all the APIs doesn't mean you can build AWS.\nAvailability, reputation, performance, domain expertise, price: all of these become critical in a world where features can be copied.","parent_id":50456631,"replies_count":0,"hn_url":"https://news.ycombinator.com/item?id=50466396"},{"id":50460482,"author":"resters","created_at":"2026-11-11T23:29:33.000Z","text":"This will make it even easier for competitors to reliably clone AWS services, which reveals that cloud is fully commoditized at this point, and advantages come down to market power (buying servers/bandwidth at scale, building data centers at scale, etc).","parent_id":50456631,"replies_count":5,"hn_url":"https://news.ycombinator.com/item?id=50460482"},{"id":50468245,"author":"tormeh","created_at":"2026-11-12T14:50:13.000Z","text":"Fun fact: You cannot compile this with 32GB of RAM without setting \"jobs\" to a low value. Haven't seen that before...","parent_id":50456631,"replies_count":0,"hn_url":"https://news.ycombinator.com/item?id=50468245"},{"id":50467076,"author":"noeleon","created_at":"2026-11-12T13:51:34.000Z","text":"Does this have all of the AWS API rate-limits baked in?","parent_id":50456631,"replies_count":0,"hn_url":"https://news.ycombinator.com/item?id=50467076"},{"id":50469124,"author":"dmtroyer","created_at":"2026-11-12T15:35:58.000Z","text":"I'm impressed, this seems like an impossible task.","parent_id":50456631,"replies_count":0,"hn_url":"https://news.ycombinator.com/item?id=50469124"},{"id":50456820,"author":"tptacek","created_at":"2026-11-11T18:34:35.000Z","text":"The title for this story should be \"aws-emulator, from AWS\".","parent_id":50456631,"replies_count":1,"hn_url":"https://news.ycombinator.com/item?id=50456820"},{"id":50460167,"author":"JoshTriplett","created_at":"2026-11-11T23:03:07.000Z","text":"This simulates API responses, like a mocking mechanism, which is enough for some testing. But if you call RunInstances, the corresponding code of the launched instance doesn't actually run. So if you have orchestration code you want to test, that depends on actually running the instances you launch, this won't test it.\nSpinifex (https://github.com/mulgadc/spinifex/) seems more promising than this, because its RunInstances actually launches VMs.","parent_id":50456631,"replies_count":0,"hn_url":"https://news.ycombinator.com/item?id=50460167"},{"id":50456891,"author":"gateauxd","created_at":"2026-11-11T18:41:13.000Z","text":"Excited to see this develop and be a free replacement to localstack / similar providers.","parent_id":50456631,"replies_count":2,"hn_url":"https://news.ycombinator.com/item?id=50456891"}]}