@leancodepl/kratos

Headless React components library for building Ory Kratos authentication flows.

Installation

npm install @leancodepl/kratos
# or
yarn add @leancodepl/kratos

API

mkKratos(queryClient, basePath, traits, SessionManager)

Creates a Kratos client factory with authentication flows, session management, and React providers.

Parameters:

• queryClient: QueryClient - React Query client instance for managing server state
• basePath: string - Base URL for the Kratos API server
• traits?: TTraitsConfig - Optional traits configuration object for user schema validation
• SessionManager?: new (props: BaseSessionManagerContructorProps) => TSessionManager - Optional session manager constructor, defaults to BaseSessionManager

Returns: Object with the following structure:

flows

Authentication flow components and hooks:

• useLogout() - Hook providing logout functionality with optional returnTo parameter
• LoginFlow - Complete login flow component with multi-step authentication support
• RecoveryFlow - Password recovery flow component with email verification and reset
• RegistrationFlow - User registration flow component with traits collection and verification
• SettingsFlow - User settings flow component for account management and profile updates
• VerificationFlow - Email verification flow component

providers

React context providers for the application:

• KratosProviders - Composite provider that wraps your app with necessary Kratos context
  • Includes KratosClientProvider for API access
  • Includes KratosSessionProvider for session management

session

Session management utilities:

• sessionManager - Session manager instance with methods and hooks for:
  • Async Methods: getSession(), getIdentity(), getUserId(), isLoggedIn(), checkIfLoggedIn()
  • React Hooks: useSession(), useIdentity(), useUserId(), useIsLoggedIn(), useIsAal2Required()
  • Extensible: Can be extended to provide trait-specific methods like useEmail(), useFirstName() for typed user data access

BaseSessionManager(queryClient, api)

Manages Ory Kratos session and identity state with React Query integration.

Parameters:

• queryClient: QueryClient - React Query QueryClient instance for caching and fetching session data
• api: FrontendApi - Ory Kratos FrontendApi instance for session and identity requests

Usage Examples

Basic Setup

To use the library, you need to create new instance of Kratos client with mkKratos factory:

// traits.ts

export const traitsConfig = {
  Email: { trait: "email", type: "string" },
  GivenName: { trait: "given_name", type: "string" },
  RegulationsAccepted: { trait: "regulations_accepted", type: "boolean" },
} as const

export type AuthTraitsConfig = typeof traitsConfig

// kratosService.ts

import { environment } from "./environments"
import { queryClient } from "./queryService"
import { traitsConfig } from "./traits"

const {
  session: { sessionManager },
  providers: { KratosProviders },
  flows: { LoginFlow, RegistrationFlow, SettingsFlow, VerificationFlow, RecoveryFlow, useLogout },
} = mkKratos({
  queryClient,
  basePath: environment.authUrl,
  traits: traitsConfig,
})

// session
export { sessionManager }

// providers
export { KratosProviders }

// flows
export { LoginFlow, RecoveryFlow, RegistrationFlow, SettingsFlow, useLogout, VerificationFlow }

And then wrap your app with KratosProviders from mkKratos:

// main.tsx

import { QueryClientProvider } from "@tanstack/react-query"
import { KratosProviders } from "./kratosService"
import { queryClient } from "./queryService"

function App() {
  return (
    <QueryClientProvider client={queryClient}>
      <KratosProviders>
        <Routes>
          <Route path="/login" element={<LoginPage />} />
          <Route path="/register" element={<RegisterPage />} />
          <Route path="/settings" element={<SettingsPage />} />
        </Routes>
      </KratosProviders>
    </QueryClientProvider>
  )
}

Extending session manager

You can add new functionalities to the session manager by extending BaseSessionManager class:

// session.ts

import { BaseSessionManager } from "@leancodepl/kratos"
import { queryClient } from "./queryService"
import type { AuthTraitsConfig } from "./traits"

export class SessionManager extends BaseSessionManager<AuthTraitsConfig> {
  getTraits = async () => {
    const identity = await this.getIdentity()

    return identity?.traits
  }

  getEmail = async () => {
    const traits = await this.getTraits()

    return traits?.email
  }

  // Hooks for React components

  useTraits = () => {
    const { identity, isLoading, error } = this.useIdentity()

    return {
      traits: identity?.traits,
      isLoading,
      error,
    }
  }

  useEmail = () => {
    const { traits, isLoading, error } = this.useTraits()

    return {
      email: traits?.email,
      isLoading,
      error,
    }
  }
}

// kratosService.ts

import { environment } from "./environments"
import { queryClient } from "./queryService"
import { SessionManager } from "./session"
import { traitsConfig } from "./traits"

const {
  session: { sessionManager },
  providers: { KratosProviders },
  flows: { LoginFlow, RegistrationFlow, SettingsFlow, VerificationFlow, RecoveryFlow, useLogout },
} = mkKratos({
  queryClient,
  basePath: environment.authUrl,
  traits: traitsConfig,
  SessionManager,
})

Session Management

import { sessionManager } from "./kratosService"

function UserProfile() {
  const { isLoggedIn, isLoading } = sessionManager.useIsLoggedIn()
  const { userId } = sessionManager.useUserId()
  const { email } = sessionManager.useEmail()
  const { firstName } = sessionManager.useFirstName()

  if (isLoading) return <div>Loading...</div>
  if (!isLoggedIn) return <div>Not logged in</div>

  return (
    <div>
      <h1>User Profile</h1>
      <p>ID: {userId}</p>
      <p>Email: {email}</p>
      <p>Name: {firstName}</p>
    </div>
  )
}

Login Flow

import { LoginFlow } from "./kratosService"

function LoginPage() {
  return (
    <LoginFlow
      loaderComponent={Loader}
      chooseMethodForm={ChooseMethodForm}
      secondFactorForm={SecondFactorForm}
      secondFactorEmailForm={SecondFactorEmailForm}
      emailVerificationForm={EmailVerificationForm}
      returnTo="/identity"
      onLoginSuccess={() => {
        console.log("Login successful")
      }}
      onSessionAlreadyAvailable={() => {
        location.href = "/identity"
      }}
      onError={({ target, errors }) => {
        console.error(`Error in ${target}:`, errors)
      }}
    />
  )
}

Registration Flow

import { RegistrationFlow } from "./kratosService"

function RegisterPage() {
  return (
    <RegistrationFlow
      chooseMethodForm={ChooseMethodForm}
      emailVerificationForm={EmailVerificationForm}
      traitsForm={TraitsForm}
      returnTo="/welcome"
      onRegistrationSuccess={() => {
        console.log("Registration successful")
      }}
      onVerificationSuccess={() => {
        console.log("Email verified")
      }}
      onError={({ target, errors }) => {
        console.error(`Registration error in ${target}:`, errors)
      }}
    />
  )
}

Settings Flow

import { SettingsFlow, settingsFlow } from "./kratosService"

function SettingsPage() {
  const { isLoggedIn, isLoading } = sessionManager.useIsLoggedIn()

  if (isLoading) return <div>Loading...</div>
  if (!isLoggedIn) return <div>Access denied</div>

  return (
    <SettingsFlow
      newPasswordForm={NewPasswordForm}
      traitsForm={TraitsForm}
      passkeysForm={PasskeysForm}
      totpForm={TotpForm}
      oidcForm={OidcForm}
      settingsForm={SettingsForm}
      onChangePasswordSuccess={() => {
        console.log("Password updated")
      }}
      onChangeTraitsSuccess={() => {
        console.log("Profile updated")
      }}
    />
  )
}

function SettingsForm({ isLoading, traitsForm, newPasswordForm, passkeysForm }: settingsFlow.SettingsFormProps) {
  if (isLoading) {
    return <div>...loading</div>
  }

  return (
    <div>
      {traitsForm}
      {newPasswordForm}
      {passkeysForm}
    </div>
  )
}

Logout Functionality

import { useLogout } from "./kratosService"

function LogoutButton() {
  const { logout } = useLogout()

  const handleLogout = async () => {
    const result = await logout({ returnTo: "/login" })
    if (result.isSuccess) {
      console.log("Logout successful")
    } else {
      console.error("Logout failed:", result.error)
    }
  }

  return <button onClick={handleLogout}>Logout</button>
}

Recovery Flow

import { RecoveryFlow } from "./kratosService"

function RecoveryPage() {
  return (
    <RecoveryFlow
      emailForm={EmailForm}
      codeForm={CodeForm}
      newPasswordForm={NewPasswordForm}
      onRecoverySuccess={() => {
        console.log("Password recovery completed")
      }}
      onError={error => {
        console.error("Recovery failed:", error)
      }}
    />
  )
}

Custom Error Handling

import { AuthError } from "@leancodepl/kratos"

function getErrorMessage(error: AuthError) {
  switch (error.id) {
    case "Error_InvalidCredentials":
      return "Invalid email or password"
    case "Error_MissingProperty":
      return "This field is required"
    case "Error_TooShort":
      return "Password is too short"
    default:
      return "An error occurred"
  }
}

function handleError({ target, errors }) {
  if (target === "root") {
    console.error("Form errors:", errors.map(getErrorMessage))
  } else {
    console.error(`Field ${target} errors:`, errors.map(getErrorMessage))
  }
}

Implementing flow form

Each form in every flow exposes slot components for inputs and buttons. When wrapping your custom components with these slots, relevant props (such as the onInput event handler) are automatically applied. If you use a custom component as a child, you receive props from one of the following types: CommonInputFieldProps, CommonCheckboxFieldProps, or CommonButtonProps.

Forms like TraitsForm have dynamic parameters determined by the traitsConfig you provide to the mkKratos factory. To type these correctly, use a generic such as registrationFlow.TraitsFormProps<AuthTraitsConfig> and pass your traits config.

Some forms are typed as discriminated unions with multiple variants.

Custom Input component with CommonInputFieldProps

import { CommonInputFieldProps } from "@leancodepl/kratos"
import { getErrorMessage } from "./kratosService"

type InputProps = CommonInputFieldProps & { placeholder?: string }

export const Input = ({ errors, ...props }: InputProps) => (
  <div>
    <input {...props} />
    {errors && errors.length > 0 && (
      <div>
        {errors.map(error => (
          <div key={error.id}>{getErrorMessage(error)}</div>
        ))}
      </div>
    )}
  </div>
)

ChooseMethodForm in login flow

import { loginFlow } from "@leancodepl/kratos"
import { LoginFlow, getErrorMessage } from "./kratosService"
import type { AuthTraitsConfig } from "./traits"

function LoginPage() {
  return (
    <LoginFlow
      chooseMethodForm={ChooseMethodForm}
      // other props
    />
  )
}

function ChooseMethodForm(props: loginFlow.ChooseMethodFormProps) {
  const { errors, isSubmitting, isValidating } = props

  if (props.isRefresh) {
    const { passwordFields, Google, Passkey, Apple, Facebook, identifier } = props

    return (
      <div>
        {identifier && (
          <h2>
            Complete login process as <strong>{identifier}</strong>
          </h2>
        )}

        {passwordFields && (
          <>
            <passwordFields.Password>
              <input placeholder="Password" />
            </passwordFields.Password>

            <passwordFields.Submit>
              <button>Login</button>
            </passwordFields.Submit>
          </>
        )}

        {Google && (
          <Google>
            <button>Sign in with Google</button>
          </Google>
        )}

        {Apple && (
          <Apple>
            <button>Sign in with Apple</button>
          </Apple>
        )}

        {Facebook && (
          <Facebook>
            <button>Sign in with Facebook</button>
          </Facebook>
        )}

        {Passkey && (
          <Passkey>
            <button>Sign in with Passkey</button>
          </Passkey>
        )}

        {errors && errors.length > 0 && (
          <div>
            {errors.map(error => (
              <div key={error.id}>{getErrorMessage(error)}</div>
            ))}
          </div>
        )}
      </div>
    )
  }

  const {
    passwordFields: { Identifier, Password, Submit },
    Google,
    Passkey,
    Apple,
    Facebook,
  } = props

  return (
    <div>
      <Identifier>
        <input placeholder="Identifier" />
      </Identifier>

      <Password>
        <input placeholder="Password" />
      </Password>

      <Submit>
        <button>Login</button>
      </Submit>

      <Google>
        <button>Sign in with Google</button>
      </Google>

      <Apple>
        <button>Sign in with Apple</button>
      </Apple>

      <Facebook>
        <button>Sign in with Facebook</button>
      </Facebook>

      <Passkey>
        <button>Sign in with Passkey</button>
      </Passkey>

      {errors && errors.length > 0 && (
        <div>
          {errors.map(error => (
            <div key={error.id}>{getErrorMessage(error)}</div>
          ))}
        </div>
      )}
    </div>
  )
}

TraitsForm in registration flow

import { registrationFlow } from "@leancodepl/kratos"
import { RegistrationFlow, getErrorMessage } from "./kratosService"
import type { AuthTraitsConfig } from "./traits"

function RegisterPage() {
  return (
    <RegistrationFlow
      traitsForm={TraitsForm}
      onError={handleError}
      // other props
    />
  )
}

function TraitsForm({
  errors,
  Email,
  RegulationsAccepted,
  GivenName,
  Google,
  Apple,
  Facebook,
  isSubmitting,
  isValidating,
}: registrationFlow.TraitsFormProps<AuthTraitsConfig>) {
  return (
    <div>
      {Email && (
        <Email>
          <input placeholder="Email" />
        </Email>
      )}
      {GivenName && (
        <GivenName>
          <input placeholder="First name" />
        </GivenName>
      )}
      {RegulationsAccepted && (
        <RegulationsAccepted>
          <input placeholder="Regulations accepted" type="checkbox">
            I accept the regulations
          </input>
        </RegulationsAccepted>
      )}

      <button type="submit">Register</button>

      {Google && (
        <Google>
          <button>Sign up with Google</button>
        </Google>
      )}

      {Apple && (
        <Apple>
          <button>Sign up with Apple</button>
        </Apple>
      )}

      {Facebook && (
        <Facebook>
          <button>Sign up with Facebook</button>
        </Facebook>
      )}

      {errors && errors.length > 0 && (
        <div>
          {errors.map(error => (
            <div key={error.id}>{getErrorMessage(error)}</div>
          ))}
        </div>
      )}
    </div>
  )
}

const handleError: registrationFlow.OnRegistrationFlowError<AuthTraitsConfig> = ({ target, errors }) => {
  if (target === "root") {
    console.error("Form errors:", errors.map(getErrorMessage))
  } else {
    console.error(`Field ${target} errors:`, errors.map(getErrorMessage))
  }
}