RDS Data API (parlel emulator)
A zero-dependency, in-process fake of the Amazon RDS Data API. Ships a tiny in-memory SQL engine (CREATE TABLE / INSERT / SELECT / UPDATE / DELETE) so round trips return real data.
| Property | Value |
|---|---|
| Port | 4722 |
| Protocol | REST/JSON (operation paths) |
| Healthcheck | GET /_parlel/health |
| Reset | POST /_parlel/reset |
Default connection
AWS_REGION=us-east-1
AWS_ENDPOINT_URL=http://127.0.0.1:4722
AWS_ACCESS_KEY_ID=parlel
AWS_SECRET_ACCESS_KEY=parlel
Supported operations / paths
| Operation | Path |
|---|---|
| ExecuteStatement | POST /Execute |
| BatchExecuteStatement | POST /BatchExecute |
| BeginTransaction | POST /BeginTransaction |
| CommitTransaction | POST /CommitTransaction |
| RollbackTransaction | POST /RollbackTransaction |
ExecuteStatement accepts sql, database, and parameters
([{ name, value: { stringValue | longValue | doubleValue | booleanValue } }])
and returns { records, columnMetadata, numberOfRecordsUpdated }.
SDK example
import { RDSDataClient, ExecuteStatementCommand } from "@aws-sdk/client-rds-data";
const data = new RDSDataClient({
region: "us-east-1",
endpoint: "http://127.0.0.1:4722",
credentials: { accessKeyId: "parlel", secretAccessKey: "parlel" },
});
await data.send(new ExecuteStatementCommand({
resourceArn: "arn:aws:rds:us-east-1:000000000000:cluster:c1",
secretArn: "arn:aws:secretsmanager:us-east-1:000000000000:secret:db",
database: "app",
sql: "CREATE TABLE users (id INTEGER, name TEXT)",
}));
Access via MCP / preview URL
Reachable through the parlel pool MCP bridge and preview URL. No auth setup required.
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 |
|---|---|
| SQL dialect | Subset only: single-table SELECT, simple WHERE col = val. |
| Joins | Not supported. |
| Transactions | transactionId is tracked but statements are not isolated. |
| Types | Values are coerced to string/long/double/boolean. |
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:4722