Reference

Configuration Options

All options are passed to errorcore.init(). Only transport is required.

Core

Option	Type	Default	Description
`transport`	`TransportConfig`	required	Where incident packages are delivered. See Transport.
`encryptionKey`	`string`	`undefined`	64-character hex string (32 bytes) for AES-256-GCM encryption. Generate with `node -e "console.log(require('crypto').randomBytes(32).toString('hex'))"`.
`allowUnencrypted`	`boolean`	`false`	Allow unencrypted packages. Set to `true` for local development when no encryption key is available.

Capture

Option	Type	Default	Description
`captureLocalVariables`	`boolean`	`false`	Capture local variables at the throw site via V8 Inspector.
`captureRequestBodies`	`boolean`	`false`	Include request bodies in captured incidents.
`captureResponseBodies`	`boolean`	`false`	Include response bodies in captured incidents.
`captureBody`	`boolean`	`false`	Shorthand to enable both request and response body capture.
`captureBodyDigest`	`boolean`	`false`	Include a SHA-256 digest of bodies instead of the full content.
`captureDbBindParams`	`boolean`	`false`	Include database bind parameters in the IO timeline.
`bodyCaptureContentTypes`	`string[]`	`["application/json", "application/x-www-form-urlencoded", "text/plain", "application/xml"]`	Content types eligible for body capture.

Filtering

Option	Type	Default	Description
`headerAllowlist`	`string[]`	`["content-type", "content-length", "accept", "user-agent", "x-request-id", "x-correlation-id", "host"]`	Headers to include in captured requests.
`headerBlocklist`	`RegExp[]`	Patterns matching authorization, cookie, token, key, secret, password, credential	Headers to exclude (evaluated as regex against header names).
`envAllowlist`	`string[]`	`NODE_ENV`, `PORT`, `HOSTNAME`, Kubernetes and cloud platform variables	Environment variables to include in the incident package.
`envBlocklist`	`RegExp[]`	Patterns matching key, secret, token, password, credential, auth, private	Environment variable names to exclude.
`piiScrubber`	`(key: string, value: unknown) => unknown`	`undefined`	Custom function to scrub or transform values before serialization. Runs in addition to the built-in scrubber.
`replaceDefaultScrubber`	`boolean`	`false`	When `true`, the custom `piiScrubber` replaces the built-in scrubber entirely instead of running alongside it.

Buffer and Performance

Option	Type	Default	Description
`bufferSize`	`number`	`200`	Maximum number of IO events kept in the circular buffer. Range: 10-100000.
`bufferMaxBytes`	`number`	`52428800` (50 MB)	Maximum memory for the IO buffer in bytes. Minimum: 1 MB.
`maxPayloadSize`	`number`	`32768` (32 KB)	Maximum size of a single serialized value in bytes.
`maxConcurrentRequests`	`number`	`50`	Maximum number of concurrent request contexts tracked.
`rateLimitPerMinute`	`number`	`60`	Maximum incidents captured per rate limit window.
`rateLimitWindowMs`	`number`	`60000`	Rate limit sliding window duration in milliseconds. Minimum: 1000.
`flushIntervalMs`	`number`	`5000`	Interval for periodic transport flush. Set to `0` to disable.

Local Variables

Option	Type	Default	Description
`maxLocalsCollectionsPerSecond`	`number`	`20`	Rate limit for V8 Inspector local variable collection.
`maxCachedLocals`	`number`	`50`	Maximum cached local variable snapshots.
`maxLocalsFrames`	`number`	`5`	Number of stack frames to capture locals from.

Serialization

Passed as serialization: { ... } in the config:

Option	Type	Default	Description
`maxDepth`	`number`	`8`	Maximum nesting depth for cloned values.
`maxArrayItems`	`number`	`20`	Maximum array elements to include.
`maxObjectKeys`	`number`	`50`	Maximum object keys to include.
`maxStringLength`	`number`	`2048`	Maximum string length before truncation.
`maxPayloadSize`	`number`	`32768`	Maximum serialized size per value (32 KB).
`maxTotalPackageSize`	`number`	`5242880`	Maximum total package size (5 MB).

Transport and Delivery

Option	Type	Default	Description
`deadLetterPath`	`string`	auto-derived	Path to the dead-letter NDJSON file. Defaults to `.errorcore-dead-letters.ndjson` next to the transport file or in CWD for HTTP transport.
`maxDrainOnStartup`	`number`	`100`	Maximum dead-letter entries to retry on SDK initialization.
`uncaughtExceptionExitDelayMs`	`number`	`1500`	Milliseconds to wait for delivery before exiting after an uncaught exception.

Advanced

Option	Type	Default	Description
`resolveSourceMaps`	`boolean`	`true`	Resolve source maps in stack traces.
`useWorkerAssembly`	`boolean`	`false`	Assemble incident packages in a worker thread to reduce main thread blocking.
`allowPlainHttpTransport`	`boolean`	`false`	Allow `http://` URLs for the HTTP transport (not recommended).
`allowInvalidCollectorCertificates`	`boolean`	`false`	Skip TLS certificate validation for the collector (not recommended).

Reference

Exact option names, shapes, and types for teams that need a direct lookup surface.

TypeScript Types

Direct lookup page for the main TypeScript-facing SDK shapes.

On this page

Configuration Options Core Capture Filtering Buffer and Performance Local Variables Serialization Transport and Delivery Advanced