Reusable secret-redaction and safe-serialization utilities for Node.js 26+. This library helps protect observability and boundary data; it is not encryption, secret storage, or a guarantee that unknown secrets are detected.
npm install @eliware/redactNode.js 26 or newer with native ESM support is required.
The repository is at version 6.0.0. The public API includes
policy creation, structured redaction, header redaction, best-effort text
redaction, literal-secret replacement, safe serialization, and error helpers.
import {
redactText,
redactValue,
safeSerialize,
} from '@eliware/redact';
redactText('Authorization: Bearer secret');
// 'Authorization: Bearer [REDACTED]'
redactValue({ token: 'secret', safe: true });
// { token: '[REDACTED]', safe: true }
safeSerialize({ token: 'secret', nested: { value: 1 } });
// { token: '[REDACTED]', nested: { value: 1 } }Structured redaction is key-based and does not mutate its input. Text
redaction is best-effort and cannot guarantee detection of unknown secrets.
Configure keys, marker, circularMarker, and serialization limits
(maxDepth, maxKeys, maxArray, and maxString) for package-specific
contracts.
Serialization limits must be non-negative integers.
Structured redaction also accepts non-negative integer maxDepth, maxKeys,
and maxArray limits; exceeding a limit emits [TRUNCATED].
Header-name heuristics can be disabled with matchHeuristics: false when
custom header policy must be exact. Custom headerNames are additive to the
default heuristic matching unless heuristics are disabled.
The supported runtime is Node.js 26 or newer; browser use does not provide
Node Buffer serialization behavior.
Structured redaction is intentionally loss-tolerant for hostile objects: if
property enumeration fails, unavailable fields are omitted from the safe result.
Safe serialization similarly reduces unsupported class instances and built-in
objects to safely readable enumerable own properties; hostile state may be
omitted by design.
Literal-secret replacement processes at most 100 configured secrets per call.
When bounded serialization omits array items, it appends [TRUNCATED]; object
truncation uses a collision-safe metadata key.
Additional boundary helpers are available for common logging paths:
redactHeaders({ authorization: 'Bearer secret', accept: 'json' });
redactErrorMessage(new Error('request token=secret'));
redactErrorDetails(Object.assign(new Error('failed'), { token: 'secret' }));
safeErrorValue(new Error('failed'));The same helpers are exported from the package entrypoint; serialization-only
limits are options to safeSerialize, not properties of defaultPolicy.
Configured literal secrets are replaced using substring semantics; empty and
non-string entries are ignored. Buffer handling is intentionally Node.js-specific.
Text redaction and error-message redaction accept only marker and secrets;
structured/header policy fields do not apply to those helpers. Header
enumeration failures are intentionally loss-tolerant and produce an empty safe
result, as hostile input cannot be represented reliably.
When both keys and the legacy redactKeys alias are supplied, keys takes
precedence; unknown policy fields are ignored by normalized policies.
npm test
npm run lint
npm run typecheck
npm run pack
The project uses @eliware/test for its test and lint gates.
Redaction is an observability and boundary-safety aid, not encryption, secret storage, access control, or a guarantee that unknown secrets are detected. Redact values before logging, persistence, transport, or browser delivery.
See documentation, specifications, examples, and release notes.
Report reproducible issues at github.com/eliware/redact/issues.
This package is distributed under the terms in LICENSE.