elbv2 — Elastic Load Balancing v2
A zero-dependency, in-process emulator for AWS ELBv2 (Application / Network / Gateway load balancers).
| Property | Value |
|---|---|
| Port | 4710 |
| Protocol | AWS Query / XML |
| API Version | 2015-12-01 |
| Health | GET /_parlel/health |
| Reset | POST /_parlel/reset |
Default connection
AWS_ENDPOINT_URL=http://127.0.0.1:4710
AWS_REGION=us-east-1
AWS_ACCESS_KEY_ID=parlel
AWS_SECRET_ACCESS_KEY=parlel
Any credentials are accepted — auth is never verified.
Supported operations
| Operation | Notes |
|---|---|
| CreateLoadBalancer | Generates ARN + DNSName |
| DescribeLoadBalancers | Filter by ARNs or Names |
| DeleteLoadBalancer | Cascades to listeners |
| CreateTargetGroup | Generates ARN |
| DescribeTargetGroups | Filter by ARNs or Names |
| DeleteTargetGroup | |
| RegisterTargets | Targets reported healthy |
| DeregisterTargets | |
| DescribeTargetHealth | |
| CreateListener | Requires existing load balancer |
| DescribeListeners | Filter by LoadBalancerArn / ARNs |
| DeleteListener | Cascades to rules |
| CreateRule | Requires existing listener |
| DescribeRules | Filter by ListenerArn / ARNs |
SDK usage example
import {
ElasticLoadBalancingV2Client,
CreateLoadBalancerCommand,
} from "@aws-sdk/client-elastic-load-balancing-v2";
const elbv2 = new ElasticLoadBalancingV2Client({
endpoint: "http://127.0.0.1:4710",
region: "us-east-1",
credentials: { accessKeyId: "parlel", secretAccessKey: "parlel" },
});
await elbv2.send(
new CreateLoadBalancerCommand({
Name: "my-alb",
Subnets: ["subnet-aaa", "subnet-bbb"],
}),
);
Access via MCP / preview URL
When launched through the parlel pool, the service is reachable at the
allocated preview URL (e.g. http://<host>:4710). Point any AWS SDK or MCP
tool at that endpoint via AWS_ENDPOINT_URL.
Surface coverage
This emulator faithfully replicates the API surface most application code and agents exercise. Anything below the supported lines is either an intentional design choice for a fast, zero-cost local emulator (✓ By design) or a candidate for a future release (⟳ Roadmap) — never a silent inaccuracy.
Legend: ✅ fully supported · ◐ accepted (stored, not strictly enforced) · ✓ by design · ⟳ on the roadmap.
| Area | Limitation |
|---|---|
| Target health | Always reported healthy (no real checks) |
| Listener rules | Stored but not evaluated for routing |
| Attributes | LB/TG attributes are not persisted |
| Tags | Accepted on create but not queryable |
| State | In-memory only; lost on restart |
Configuration — test.env
Copy these into your test.env (used by the bridge sidecar flow). Tokens are Parlel's seeded test credentials — any non-empty value is accepted by the emulator, so you rarely need to change them. Swap in real credentials only when pointing at the live service in prod.env.
AWS_ACCESS_KEY_ID=parlel
AWS_SECRET_ACCESS_KEY=parlel
AWS_REGION=us-east-1
AWS_ENDPOINT_URL=http://parlel-bridge:4710