Authentication endpoints: register and login

The KERN API has two public authentication endpoints. Neither requires an existing token. Both return a LoginResponse containing a JWT access token and the full user object.

POST /register

Registers a new user account and returns a JWT access token immediately. No email verification step is required. Auth required: No

Request body

username

string

required

Unique display name for the account. Must not already exist in the database.

string

required

Email address. Must be unique across all accounts.

password

string

required

Plain-text password. Stored as a SHA-256 hash — never in plain text.

full_name

string

User’s full name. Optional.

phone

string

Phone number. Optional.

Response — 200

accessToken

string

required

Signed JWT token. Valid for 30 minutes. Use as Authorization: Bearer <accessToken>.

token_type

string

required

Always "bearer".

user

object

required

Show user properties

integer

Auto-incremented user ID.

username

string

The username that was registered.

string

The email address that was registered.

full_name

string

Full name, if provided.

phone

string

Phone number, if provided.

avatar_url

string

URL of the user’s avatar image. null on registration.

role

string

Always "user" for newly registered accounts.

bio

string

Short biography. null on registration.

has_completed_quiz

boolean

Whether the user has completed the onboarding questionnaire. Always false on registration.

assigned_routine

string

The routine type assigned after quiz completion. null on registration.

created_at

string

ISO 8601 timestamp of account creation.

disabled

boolean

Whether the account is disabled. Always false on registration.

Errors

Status	`detail`	Cause
`400`	`"El usuario o email ya existe"`	`username` or `email` is already taken

Example

curl --request POST \
  --url https://kern-api.vercel.app/register \
  --header "Content-Type: application/json" \
  --data '{
    "username": "jaime",
    "email": "jaime@example.com",
    "password": "mypassword123",
    "full_name": "Jaime Gayo"
  }'

Authenticates an existing user with their email address and password, and returns a fresh JWT access token. Auth required: No

Request body

string

required

The email address used when registering the account.

password

string

required

The account password in plain text. The API compares its SHA-256 hash against the stored hash.

Response — 200

Same LoginResponse structure as POST /register. See the response fields above.

Errors

Status	`detail`	Cause
`401`	`"Email o contraseña incorrectos"`	No account found for that email, or password hash does not match

Example

curl --request POST \
  --url https://kern-api.vercel.app/login \
  --header "Content-Type: application/json" \
  --data '{
    "email": "jaime@example.com",
    "password": "mypassword123"
  }'

Overview

Endpoints

Data Models

Authentication endpoints: register and login

POST /register

Request body

Response — 200

Errors

Example

Request body

Response — 200

Errors

Example

Build docs developers (and LLMs) love

Overview

Endpoints

Data Models

Documentation Index

​POST /register

​Request body

​Response — 200

​Errors

​Example

​POST /login

​Request body

​Response — 200

​Errors

​Example

Build docs developers (and LLMs) love

POST /register

Request body

Response — 200

Errors

Example

POST /login

Request body

Response — 200

Errors

Example