> ## Documentation Index
> Fetch the complete documentation index at: https://docs.niadra.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Start the SSO sign-in

> The identity provider address, with a fresh state, nonce and PKCE challenge.



## OpenAPI

````yaml openapi/en/control.json POST /v1/auth/sso/start
openapi: 3.1.0
info:
  title: Niadra control API
  version: '1'
  description: >-
    Tenants, projects, sources, keys, people, configuration and usage. It never
    receives customer content.
servers:
  - url: https://control.api.niadra.com
security: []
paths:
  /v1/auth/sso/start:
    post:
      summary: Start the SSO sign-in
      description: >-
        The identity provider's address for this e-mail, with a fresh state,
        nonce and PKCE challenge. Only

        the Console's origins may start (403 otherwise): the provider's answer
        comes back to that origin.


        **Authentication.** No authentication.
      operationId: start_v1_auth_sso_start_post
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SsoStartRequest'
            example:
              email: nina@acme.example
              binding: E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM
        required: true
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SsoStartOut'
              example:
                authorize_url: >-
                  https://login.acme.example/authorize?response_type=code&client_id=niadra-console&redirect_uri=https%3A%2F%2Fcontrol.api.niadra.com%2Fv1%2Fauth%2Fsso%2Foidc%2Fcallback&scope=openid+email+profile+groups&state=Zk9x...&nonce=Pq2w...&code_challenge=K8Hm...&code_challenge_method=S256&login_hint=nina%40acme.example
                expires_at: '2026-09-24T12:10:00Z'
          description: The address of the identity provider, where the browser goes.
        '422':
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/Problem'
          description: The request does not match the contract.
      security: []
components:
  schemas:
    SsoStartRequest:
      additionalProperties: false
      properties:
        binding:
          description: >-
            base64url, without padding, of the SHA-256 of a random value the
            Console keeps for this tab and sends again at the exchange.
          pattern: ^[A-Za-z0-9_-]{43}$
          title: Binding
          type: string
        email:
          maxLength: 320
          minLength: 3
          title: Email
          type: string
      required:
        - email
        - binding
      title: SsoStartRequest
      type: object
    SsoStartOut:
      additionalProperties: false
      properties:
        authorize_url:
          description: 'Where to send the browser: the provider''s sign-in.'
          title: Authorize Url
          type: string
        expires_at:
          format: date-time
          title: Expires At
          type: string
      required:
        - authorize_url
        - expires_at
      title: SsoStartOut
      type: object
    Problem:
      additionalProperties: false
      description: RFC 9457 problem details; `code` comes from the versioned error catalog.
      properties:
        code:
          title: Code
          type: string
        detail:
          anyOf:
            - type: string
            - type: 'null'
          default: null
          title: Detail
        request_id:
          anyOf:
            - type: string
            - type: 'null'
          default: null
          title: Request Id
        status:
          title: Status
          type: integer
        title:
          title: Title
          type: string
        type:
          default: about:blank
          title: Type
          type: string
      required:
        - title
        - status
        - code
      title: Problem
      type: object

````