@walkeros/transformer-validate

Enforce JSON Schema contracts on walkerOS events at runtime. Checks each event against its contract and records a verdict, either annotating the event and continuing or dropping it. Runs on both web and server.

Documentation • NPM Package • Source Code

Installation

npm install @walkeros/transformer-validate

Quick start

import { startFlow } from '@walkeros/collector';
import { transformerValidate } from '@walkeros/transformer-validate';

await startFlow({
  transformers: {
    validate: {
      code: transformerValidate,
      config: { settings: { contract: [contractWeb], mode: 'strict' } },
    },
  },
});

The same step in a bundled flow, referencing a named contract from the top-level contract block:

{
  "version": 4,
  "contract": {
    "web": {
      "events": {
        "order": {
          "complete": {
            "properties": { "data": { "required": ["total", "currency"] } }
          }
        }
      }
    }
  },
  "flows": {
    "default": {
      "transformers": {
        "validate": {
          "package": "@walkeros/transformer-validate",
          "config": {
            "settings": { "contract": ["$contract.web"], "mode": "strict" }
          },
          "next": "ga4"
        }
      }
    }
  }
}

Modes

mode decides what happens to an invalid event:

• pass (default) writes the verdict to the event and continues, so a downstream step can route on event.source.valid.
• strict records the errors and stops the chain, so the event never reaches downstream steps.

The boolean verdict goes onto the event as data that travels with it. The issue list goes onto the ingest as diagnostics, so it survives even a strict-mode drop.

Documentation

Full configuration, contract references, and examples live in the docs: https://www.walkeros.io/docs/transformers/validate

Contribute

Feel free to contribute by submitting an issue, starting a discussion, or getting in contact.

License

MIT