Redaction & PII protection

RedactionPolicy lets you redact sensitive values from narratives and snapshots without changing business logic. Recorders see [REDACTED], runtime gets real values.

Setting a policy

Call executor.setRedactionPolicy() before run(). One config covers three dimensions:

import { flowChart, FlowChartExecutor } from 'footprintjs';

interface RegistrationState {
  ssn: string;
  email: string;
  dbPassword: string;
  authToken: string;
  patient: {
    name: string;
    ssn: string;
    dob: string;
    bloodType: string;
    address: { street: string; city: string; zip: string };
  };
  verified?: boolean;
}

const chart = flowChart<RegistrationState>('Register', async (scope) => {
  scope.ssn = '999-88-7777';
  scope.email = 'alice@example.com';
  scope.dbPassword = 'hunter2';
  scope.authToken = 'bearer-xyz-789';
  scope.patient = {
    name: 'Alice Johnson',
    ssn: '999-88-7777',
    dob: '1990-05-15',
    bloodType: 'O+',
    address: { street: '123 Main St', city: 'LA', zip: '90210' },
  };
}, 'register')
  .addFunction('Process', async (scope) => {
    // Runtime gets real values — business logic works normally
    scope.verified = scope.ssn.length > 0;
  }, 'process')
  .build();

const executor = new FlowChartExecutor(chart);

executor.setRedactionPolicy({
  keys: ['ssn'],                                // exact key match
  patterns: [/password|token|secret/i],          // regex pattern match
  fields: { patient: ['ssn', 'dob', 'address.zip'] }, // nested field scrubbing
});

executor.enableNarrative();
await executor.run();

Three dimensions

Dimension	Config	What it matches
`keys`	`['ssn', 'password']`	Exact top-level key names
`patterns`	`[/token	secret/i]`
`fields`	`{ patient: ['ssn', 'dob'] }`	Specific nested paths within objects

What gets redacted

Narrative — writes show [REDACTED] instead of the value
Snapshots — getSnapshot() scrubs redacted keys
Recorders — all recorder hooks receive redacted values

Runtime code (scope.ssn, scope.patient.dob) still gets the real value. Redaction is an observation-layer concern.

Redaction report

After execution, executor.getRedactionReport() returns a compliance-friendly audit trail:

const report = executor.getRedactionReport();
console.log(report.redactedKeys);     // ['ssn']
console.log(report.fieldRedactions);  // { patient: ['ssn', 'dob', 'address.zip'] }
console.log(report.patterns);         // [/password|token|secret/i]

Subflow redaction

Redaction policies propagate to subflows automatically. See examples/features/17-subflow-redaction.ts for a working example.

Try it live

Redaction — keys, patterns, and field-level scrubbing