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name cognito
description AWS Cognito user authentication and authorization service. Use when setting up user pools, configuring identity pools, implementing OAuth flows, managing user attributes, or integrating with social identity providers.
metadata
last_updated doc_source
2026-01-07

AWS Cognito

Common Patterns

Create User Pool

AWS CLI:

aws cognito-idp create-user-pool \
  --pool-name my-app-users \
  --policies '{
    "PasswordPolicy": {
      "MinimumLength": 12,
      "RequireUppercase": true,
      "RequireLowercase": true,
      "RequireNumbers": true,
      "RequireSymbols": true
    }
  }' \
  --auto-verified-attributes email \
  --username-attributes email \
  --mfa-configuration OPTIONAL \
  --user-attribute-update-settings '{
    "AttributesRequireVerificationBeforeUpdate": ["email"]
  }'

Create App Client

# Verify user pool created
aws cognito-idp describe-user-pool --user-pool-id us-east-1_abc123 --query UserPool.Status

aws cognito-idp create-user-pool-client \
  --user-pool-id us-east-1_abc123 \
  --client-name my-web-app \
  --generate-secret \
  --explicit-auth-flows ALLOW_USER_SRP_AUTH ALLOW_REFRESH_TOKEN_AUTH \
  --supported-identity-providers COGNITO \
  --callback-urls https://myapp.com/callback \
  --logout-urls https://myapp.com/logout \
  --allowed-o-auth-flows code \
  --allowed-o-auth-scopes openid email profile \
  --allowed-o-auth-flows-user-pool-client \
  --access-token-validity 60 \
  --id-token-validity 60 \
  --refresh-token-validity 30 \
  --token-validity-units '{
    "AccessToken": "minutes",
    "IdToken": "minutes",
    "RefreshToken": "days"
  }'

Sign Up User

import boto3
import hmac
import hashlib
import base64

cognito = boto3.client('cognito-idp')

def get_secret_hash(username, client_id, client_secret):
    message = username + client_id
    dig = hmac.new(
        client_secret.encode('utf-8'),
        message.encode('utf-8'),
        digestmod=hashlib.sha256
    ).digest()
    return base64.b64encode(dig).decode()

response = cognito.sign_up(
    ClientId='client-id',
    SecretHash=get_secret_hash('user@example.com', 'client-id', 'client-secret'),
    Username='user@example.com',
    Password='SecurePassword123!',
    UserAttributes=[
        {'Name': 'email', 'Value': 'user@example.com'},
        {'Name': 'name', 'Value': 'John Doe'}
    ]
)

Confirm Sign Up

cognito.confirm_sign_up(
    ClientId='client-id',
    SecretHash=get_secret_hash('user@example.com', 'client-id', 'client-secret'),
    Username='user@example.com',
    ConfirmationCode='123456'
)

Authenticate User

response = cognito.initiate_auth(
    ClientId='client-id',
    AuthFlow='USER_SRP_AUTH',
    AuthParameters={
        'USERNAME': 'user@example.com',
        'SECRET_HASH': get_secret_hash('user@example.com', 'client-id', 'client-secret'),
        'SRP_A': srp_a  # From SRP library
    }
)

# For simple password auth (not recommended for production)
response = cognito.admin_initiate_auth(
    UserPoolId='us-east-1_abc123',
    ClientId='client-id',
    AuthFlow='ADMIN_USER_PASSWORD_AUTH',
    AuthParameters={
        'USERNAME': 'user@example.com',
        'PASSWORD': 'password',
        'SECRET_HASH': get_secret_hash('user@example.com', 'client-id', 'client-secret')
    }
)

tokens = response['AuthenticationResult']
id_token = tokens['IdToken']
access_token = tokens['AccessToken']
refresh_token = tokens['RefreshToken']

Refresh Tokens

response = cognito.initiate_auth(
    ClientId='client-id',
    AuthFlow='REFRESH_TOKEN_AUTH',
    AuthParameters={
        'REFRESH_TOKEN': refresh_token,
        'SECRET_HASH': get_secret_hash('user@example.com', 'client-id', 'client-secret')
    }
)

Create Identity Pool

aws cognito-identity create-identity-pool \
  --identity-pool-name my-app-identities \
  --allow-unauthenticated-identities \
  --cognito-identity-providers \
    ProviderName=cognito-idp.us-east-1.amazonaws.com/us-east-1_abc123,\
ClientId=client-id,\
ServerSideTokenCheck=true

Get AWS Credentials

import boto3

cognito_identity = boto3.client('cognito-identity')

# Get identity ID
response = cognito_identity.get_id(
    IdentityPoolId='us-east-1:12345678-1234-1234-1234-123456789012',
    Logins={
        'cognito-idp.us-east-1.amazonaws.com/us-east-1_abc123': id_token
    }
)
identity_id = response['IdentityId']

# Get credentials
response = cognito_identity.get_credentials_for_identity(
    IdentityId=identity_id,
    Logins={
        'cognito-idp.us-east-1.amazonaws.com/us-east-1_abc123': id_token
    }
)

credentials = response['Credentials']
# Use credentials['AccessKeyId'], credentials['SecretKey'], credentials['SessionToken']

CLI Reference

User Pool

Command Description
aws cognito-idp create-user-pool Create user pool
aws cognito-idp describe-user-pool Get pool details
aws cognito-idp update-user-pool Update pool settings
aws cognito-idp delete-user-pool Delete pool
aws cognito-idp list-user-pools List pools

Users

Command Description
aws cognito-idp admin-create-user Create user (admin)
aws cognito-idp admin-delete-user Delete user
aws cognito-idp admin-get-user Get user details
aws cognito-idp list-users List users
aws cognito-idp admin-set-user-password Set password
aws cognito-idp admin-disable-user Disable user

Authentication

Command Description
aws cognito-idp initiate-auth Start authentication
aws cognito-idp respond-to-auth-challenge Respond to MFA
aws cognito-idp admin-initiate-auth Admin authentication

Best Practices

Security

  • Enable MFA for all users (at least optional)
  • Use strong password policies
  • Enable advanced security features (adaptive auth)
  • Verify email/phone before allowing sign-in
  • Use short token lifetimes for sensitive apps
  • Never expose client secrets in frontend code

User Experience

  • Use hosted UI for quick implementation
  • Customize UI with CSS
  • Implement proper error handling
  • Provide clear password requirements

Architecture

  • Use identity pools for AWS resource access
  • Use access tokens for API Gateway
  • Store refresh tokens securely
  • Implement token refresh before expiry

Troubleshooting

User Cannot Sign In

Causes:

  • User not confirmed
  • Password incorrect
  • User disabled
  • Account locked (too many attempts)

Debug:

aws cognito-idp admin-get-user \
  --user-pool-id us-east-1_abc123 \
  --username user@example.com

Token Validation Failed

Causes:

  • Token expired
  • Wrong user pool/client ID
  • Token signature invalid

Validate JWT:

import jwt
import requests

# Get JWKS
jwks_url = f'https://cognito-idp.us-east-1.amazonaws.com/us-east-1_abc123/.well-known/jwks.json'
jwks = requests.get(jwks_url).json()

# Decode and verify (use python-jose or similar)
from jose import jwt

claims = jwt.decode(
    token,
    jwks,
    algorithms=['RS256'],
    audience='client-id',
    issuer='https://cognito-idp.us-east-1.amazonaws.com/us-east-1_abc123'
)

Hosted UI Not Working

Check:

  • Callback URLs configured correctly
  • Domain configured for user pool
  • OAuth settings enabled
# Check domain
aws cognito-idp describe-user-pool \
  --user-pool-id us-east-1_abc123 \
  --query 'UserPool.Domain'

Rate Limiting

Symptom: TooManyRequestsException

Solutions:

  • Implement exponential backoff
  • Request quota increase
  • Cache tokens appropriately

References