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2.0.0 • Public • Published

@tshttp/error 💢

The ultimate HTTP error to throw.
Built with a simple and discoverable API surface, highly typed, with augmentation in mind.

Get started

Requires at least typescript 4.0.

yarn add @tshttp/error
npm install @tshttp/error
import { HttpError } from '@tshttp/error'

throw new HttpError(400)
throw new HttpError(500, 'My bad')

Attached properties


The resulting error has a status property that will be used, for example by Express and Fastify error handlers, to properly set the HTTP response status.


The resulting error name property will be inferred from status: e.g. "NotFound" for 404.

If you use a unknown error status code, the error name will be "HttpError".

Need more?

Have a look at the Augmentations section.


To respect the inherited Error, non-enumerable properties are kept non-enumerable: name, message, stack.
They won't be serialized by JSON.stringify (MDN reference).

Dedicated static methods

Instead of passing the status code, the known HTTP errors are exposed as static methods: List of HTTP errors.

throw HttpError.Unauthorized('Get out')
// HttpError { status: 400, name: 'Unauthorized', message: 'Get out' }

throw HttpError.InternalServerError('My bad') 
// HttpError { status: 500, name: 'InternalServerError', message: 'My bad' }

Optional new keyword

You can instantiate HttpError with or without the new keyword, just like the built-in Error constructor.

throw HttpError(401)

The compiler is okay with both. 👌


By default, the only parameter you can pass besides the status code is message?: string. You might want your error objects to have more details.

A dedicated namespace Augmentation gives the possibility, for each different status, to change the optional message parameter to a required data object parameter. This object's properties will be attached to the resulting error (at runtime and compile time).

export {} // necessary to be in a module file

declare module '@tshttp/error' {
  namespace Augmentation {
    interface Forbidden {
      access: 'read' | 'create' | 'update' | 'delete'
      target: string

    // Could be useful for custom headers since frameworks usually set the response headers with the error headers property:
    interface MethodNotAllowed {
      headers: {
        allow: ('GET' | 'POST' | 'PUT' | 'PATCH' | 'DELETE')[]

throw HttpError(403, { access: 'read', target: 'user' })
// HttpError { status: 400, name: 'Forbidden', access: 'read', target: 'user' }

throw HttpError.MethodNotAllowed({ headers: { allow: ['GET'] } })
// HttpError { status: 505, name: 'MethodNotAllowed', headers: { allow: ['GET'] } }

Every known HTTP error is available for augmentation under its own name: List of HTTP errors.

If you want to augment every HTTP error at once, use the AnyHttpError interface.


With the Constraint interface, you can:

  • Whitelist the errors you application uses.
declare module '@tshttp/error' {
  namespace Augmentation {
    interface Constraint {
      status: 400 | 401 | 403 | 404 | 405 | 422 | 500
      // or widen to all numbers with `status: number`
  • Force usage of static methods.
declare module '@tshttp/error' {
  namespace Augmentation {
    interface Constraint {
      constructor: false

HttpError(400) // Compile time error
HttpError.BadRequest() // Ok

message property stringification

If you define a message property with different type than string, like so:

declare module '@tshttp/error' {
  namespace Augmentation {
    interface AnyHttpError {
      message: Record<string, any>

it will always be stringified to respect the original Error interface (at runtime and compile time).


throw HttpError(400, { message: { about: 'thing' } })

gives the following stack trace:

BadRequest: {"about":"thing"} # instead of "BadRequest: [Object object]"
    at ...


Since these augmentations affect the error object itself, you cannot define the following properties: name, status, stack, __proto__, constructor, prototype.

List of HTTP errors

Status Name
400 BadRequest
401 Unauthorized
402 PaymentRequired
403 Forbidden
404 NotFound
405 MethodNotAllowed
406 NotAcceptable
407 ProxyAuthenticationRequired
408 RequestTimeout
409 Conflict
410 Gone
411 LengthRequired
412 PreconditionFailed
413 PayloadTooLarge
414 URITooLong
415 UnsupportedMediaType
416 RequestedRangeNotSatisfiable
417 ExpectationFailed
418 ImATeapot
421 MisdirectedRequest
422 UnprocessableEntity
423 Locked
424 FailedDependency
425 UnorderedCollection
426 UpgradeRequired
428 PreconditionRequired
429 TooManyRequests
431 RequestHeaderFieldsTooLarge
451 UnavailableForLegalReasons
500 InternalServerError
501 NotImplemented
502 BadGateway
503 ServiceUnavailable
504 GatewayTimeout
505 HTTPVersionNotSupported
506 VariantAlsoNegotiates
507 InsufficientStorage
508 LoopDetected
509 BandwidthLimitExceeded
510 NotExtended
511 NetworkAuthenticationRequired


npm i @tshttp/error

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  • jeben