Auth Service

This page documents the core API surface of the module (primarily AuthService).

AuthService is the main abstraction exported by nestjs-auth-module.

It provides a consistent API for generating and validating tokens, regardless of which provider is selected (e.g. JWT).

Methods

Method	Description
generateAsync(payload, options?)	Generates a token from a payload and optional provider-specific options.
verifyAsync(token)	Returns true if the token is valid, otherwise false.
decodeAsync(token)	Decodes the token and returns the payload. Throws if invalid/expired.

Using AuthService in your application

Once you register AuthModule (see Installation), you can inject AuthService into your own services/controllers.

generateAsync(payload, options?)

options is provider-specific and is passed directly to the selected provider implementation.

All providers return a common response shape from generateAsync.

Field	Type	Description
token	string	The generated access token.
expiresIn	string | number	Expiration information returned by the provider. The current JWT provider returns an ISO date string.

Use this to issue a new token.

auth.controller.ts

import { Body, Controller, Post } from '@nestjs/common';
import { AuthService } from 'nestjs-auth-module';

@Controller('auth')
export class AuthController {
  constructor(private readonly authService: AuthService) {}

  @Post('token')
  async createToken(@Body() body: { userId: string }) {
    // payload shape is provider-agnostic; keep it JSON-serializable
    return this.authService.generateAsync({ userId: body.userId });
  }
}

verifyAsync(token)

Use this when you only need a boolean answer (no payload).

auth.controller.ts

import { Controller, Get, Headers, UnauthorizedException } from '@nestjs/common';
import { AuthService } from 'nestjs-auth-module';

@Controller('auth')
export class AuthController {
  constructor(private readonly authService: AuthService) {}

  @Get('verify')
  async verify(@Headers('authorization') authorization?: string) {
    const token = authorization?.split(' ')[1];
    if (!token) throw new UnauthorizedException('No token');

    const ok = await this.authService.verifyAsync(token);
    return { ok };
  }
}

decodeAsync(token)

Use this when you need the decoded payload. It is expected to throw for invalid/expired tokens.

auth.controller.ts

import { Controller, Get, Headers, UnauthorizedException } from '@nestjs/common';
import { AuthService } from 'nestjs-auth-module';

@Controller('auth')
export class AuthController {
  constructor(private readonly authService: AuthService) {}

  @Get('decode')
  async decode(@Headers('authorization') authorization?: string) {
    const token = authorization?.split(' ')[1];
    if (!token) throw new UnauthorizedException('No token');

    const payload = await this.authService.decodeAsync(token);
    return { payload };
  }
}

Notes

• Prefer verifyAsync when you only need a boolean result.
• Use decodeAsync when you want the payload; handle the thrown error as an unauthorized flow.
• Provider-specific options (like expiresIn / algorithm for JWT) are documented under Providers.