SSM contract

The account baseline writes, the constructs read. Paths are rooted at ssmRootPrefix (default /platform). See ADR 0003 for the full list.

Reading in CDK

const params = PlatformStack.of(this).params;
params.env.dnsZoneId(); // context lookup, needed at synth
params.env.certificateArn(); // context lookup
params.env.alertTopicArn("high"); // deploy-time token
params.account.kmsKeyArn(); // deploy-time token

Reading at runtime

import { platformParams } from "@rpallas/outcrop-runtime";
const busName = await platformParams().env("dev").eventBusName();

Adding a key

1. Add the path builder to PlatformParameterPaths in packages/outcrop/src/params/paths.ts.
2. Add the writer in the relevant outcrop-account module.
3. Add the reader to PlatformParameters and platformParams().
4. Document it in ADR 0003.