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

# Start Browser Login



## OpenAPI

````yaml /api-reference/customer-api.v1.openapi.json post /v1/admin/sessions/authorize
openapi: 3.1.0
info:
  title: Mount Thor Customer API
  version: v1
servers:
  - description: Mount Thor customer API edge
    url: https://api.mountthor.com
security: []
paths:
  /v1/admin/sessions/authorize:
    post:
      tags:
        - sessions
      summary: Start Browser Login
      operationId: create_login_request
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateLoginRequestRequest'
        required: true
      responses:
        '201':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CreateLoginRequestResponse'
          description: SSO authorization started
        '400':
          description: Request body failed validation
        '404':
          description: >-
            Identity federation disabled, or customer / identity integration not
            found
        '429':
          content:
            text/plain:
              schema:
                type: string
          description: Rate limit exceeded
          headers:
            Retry-After:
              description: Seconds before retry.
              schema:
                minimum: 1
                type: integer
      security:
        - {}
components:
  schemas:
    CreateLoginRequestRequest:
      additionalProperties: false
      properties:
        cli_verifier_sha256:
          description: SHA-256 hex digest of the CLI's verifier random value.
          type: string
        customer_slug:
          example: acme
          type:
            - string
            - 'null'
        localhost_redirect_uri:
          description: |-
            CLI's localhost callback URI. Must match
            `http://127.0.0.1:<port>/callback` with a non-privileged port and no
            query, fragment, or credentials.
          example: http://127.0.0.1:54321/callback
          type: string
        localhost_state_sha256:
          description: SHA-256 hex digest of the CLI's localhost-state random value.
          type: string
        tenant_slug:
          description: |-
            Optional tenant slug to scope the eventual session to a specific
            tenant. When omitted the human session is account-scoped.

            Only valid alongside `customer_slug` — the no-slug consumer flow
            cannot pre-bind a tenant because the customer is unresolved
            until callback. The resolved session in the consumer flow is
            always account-scoped.
          example: acme-prod
          type:
            - string
            - 'null'
      required:
        - localhost_redirect_uri
        - localhost_state_sha256
        - cli_verifier_sha256
      type: object
    CreateLoginRequestResponse:
      additionalProperties: false
      description: Response body for `POST /v1/admin/login-requests`.
      properties:
        authorization_url:
          example: https://api.workos.com/sso/authorize?...
          type: string
        login_request_id:
          description: Stable Mount Thor identifier for this login attempt.
          format: uuid
          type: string
        state_expires_in_seconds:
          example: 1800
          format: int64
          type: integer
      required:
        - login_request_id
        - authorization_url
        - state_expires_in_seconds
      type: object

````