From the source
- The feature answers a review problem: when an app must be copied out and deployed elsewhere before it can be seen, every change waits for a deployment and the review loop slows to that pace.
- Each session gets its own endpoint, and developers choose which ports it reaches by setting allowedPorts in CreateAgentRuntime, with one to five entries, each a single port or a range within 8000–12000, excluding reserved platform ports.
- The URL arrives in the InvokeAgentRuntime response header, and every request is authenticated: IAM runtimes require a SigV4 signature plus bedrock-agentcore:InvokeAgentRuntimeProxy, while JWT-authorizer runtimes carry a bearer token, so knowing the URL does not grant access.
- Clients connect on port 443 and a host-name prefix selects the port inside the session, and HTTP/1.1, HTTP/2, server-sent events, gRPC and WebSocket traffic all pass through.
- Because a browser cannot add a signature itself, the bedrock-agentcore SDK's Session endpoint client opens a local endpoint that adds credentials before forwarding.
- The URL lasts only as long as the session, so Amazon says apps meant for users should be deployed to a hosting service such as AWS Amplify Hosting.
aws.amazon.com