409 on Lambda Permission, too many concurrent permissions updates with Function URLS
Author: imaginaryCornCreated Jun 22, 2026Updated Aug 31, 2026
Hello!
We're hitting an issue with the first time deploy of sst.aws.React on function url creation and the permissions created therein:
Mon, 22 Jun 2026 04:53:32 GMT | Created ***Site sst:aws:React → ***SiteServerUswest2Function aws:lambda:Function (15.2s)
Mon, 22 Jun 2026 04:53:32 GMT | Created ***Site sst:aws:React (19.8s)
Mon, 22 Jun 2026 04:53:32 GMT | Created ***Site sst:aws:React → ***SiteServerUswest2InvokeFunction aws:lambda:Permission
Mon, 22 Jun 2026 04:53:32 GMT | Error ***Site sst:aws:React → ***SiteServerUswest2Url aws:lambda:FunctionUrl
Mon, 22 Jun 2026 04:53:32 GMT sdk-v2/provider2.go:572: sdk.helper_schema: adding Lambda Function URL (a-sst-dev-stack-*-
***SiteServerUswest2Function-**) permission operation error Lambda: AddPermission, https response error StatusCode: 409, RequestID: **,
ResourceConflictException: The function could not be updated due to a concurrent update operation.: [email protected]
Mon, 22 Jun 2026 04:53:32 GMT | Created ***Site sst:aws:React → ***SiteServerUswest2PublicFunctionUrlAccess aws:lambda:Permission
Mon, 22 Jun 2026 04:53:32 GMT | Created ***Site sst:aws:React → ***SitePublicFunctionUrlAccessUswest2 aws:lambda:Permission
Appears that permissions creation are done asap in parallel for the Function, so CreateFunctionUrlConfig + both AddPermission calls mutate the same function's resource policy concurrently, causing 409 on occasion, especially for SST stacks created anew for development environments per PR.
Source: anomalyco/sst