> ## Documentation Index > Fetch the complete documentation index at: https://docs.knotapi.com/llms.txt > Use this file to discover all available pages before exploring further. # Create Session > Create a session and use it to initialize the SDK. The value you receive in this endpoint should be subsequently passed into `KnotConfiguration` class of the SDK during initialization. Sessions last **30 minutes**. It is best practice to create a new session each time you initialize the SDK and not log the session in any internal or 3rd party tooling. ## OpenAPI ````yaml POST /session/create openapi: 3.1.0 info: title: Knot API description: An API to interact with the Knot merchant connectivity platform. version: 1.0.0 servers: - url: https://development.knotapi.com description: Development server security: - basicAuth: [] paths: /session/create: post: description: Create a session and use it to initialize the SDK. operationId: session_create requestBody: description: The input parameters required for creating a session. content: application/json: schema: type: object properties: type: type: string enum: - card_switcher - transaction_link - link - vault description: Product to associate the session with. example: card_switcher external_user_id: type: string description: Your unique identifier for the user. example: 123abc card_id: type: - string - 'null' description: >- Your unique identifier for a specific card. **Required when `type = card_switcher`.** Optionally accepted when `type = vault`. example: 81n9al10a0ayn13 default: null email: type: - string - 'null' description: >- User's email address. When provided, Knot will automatically detect the user's online merchant accounts to personalize the experience in the SDK. example: ada.lovelace@gmail.com default: null phone_number: type: - string - 'null' description: >- User's phone number in E.164 format. When provided, Knot will automatically detect the user's online merchant accounts to personalize the experience in the SDK. example: '+11234567890' default: null processor_token: type: - string - 'null' description: >- Plaid processor_token if using transaction data from Plaid to detect merchants. default: null metadata: type: - object - 'null' additionalProperties: type: string maxLength: 500 maxProperties: 10 description: >- Optional key-value pairs to include in webhook payloads. Maximum 10 keys, 500 characters per value. example: reference_token: abc123 trace_id: def456 default: null required: - type - external_user_id examples: CardSwitcher: summary: Card Switcher value: type: card_switcher external_user_id: abc123 card_id: 81n9al10a0ayn13 merchant_id: 45 email: ada.lovelace@gmail.com phone_number: '+11234567890' TransactionLink: summary: Transaction Link value: type: transaction_link external_user_id: abc123 merchant_id: 45 Link: summary: Link value: type: link external_user_id: abc123 merchant_id: 45 Vault: summary: Vault value: type: vault external_user_id: abc123 merchant_id: 45 responses: '200': description: Successful request. content: application/json: schema: type: object properties: session: type: string description: A session. example: 915efe72-5136-4652-z91q-d9d48003c102 '400': description: Bad request. content: application/json: schema: $ref: '#/components/schemas/Error' examples: CardIdRequired: summary: 'card_id is missing for type: card_switcher' value: error_type: INVALID_REQUEST error_code: INVALID_FIELD error_message: The card_id field is required when type = card_switcher. ExternalUserIdRequired: summary: external_user_id is missing value: error_type: INVALID_REQUEST error_code: INVALID_FIELD error_message: The external user id field is required. TypeRequired: summary: type is missing value: error_type: INVALID_REQUEST error_code: INVALID_FIELD error_message: The type field is required. InvalidPhoneNumber: summary: Phone number is invalid value: error_type: INVALID_REQUEST error_code: INVALID_FIELD error_message: The phone number format is invalid. InvalidEmail: summary: Email is invalid value: error_type: INVALID_REQUEST error_code: INVALID_FIELD error_message: The email must be a valid email address. InvalidProcessorToken: summary: Processor token is invalid value: error_type: INVALID_REQUEST error_code: INVALID_FIELD error_message: The processor token must be a string. InvalidCardBlocked: summary: card.blocked is invalid value: error_type: INVALID_REQUEST error_code: INVALID_FIELD error_message: The card.blocked field must be true or false. '401': description: Unauthorized request. content: application/json: schema: $ref: '#/components/schemas/Error' examples: AuthFailed: summary: Auth failed value: error_type: INVALID_INPUT error_code: INVALID_API_KEYS error_message: Invalid client_id or secret provided. '403': description: Forbidden request. content: application/json: schema: $ref: '#/components/schemas/Error' examples: NoAccess: summary: No access value: error_type: INVALID_REQUEST error_code: NO_ACCESS error_message: >- The type is not enabled. Please contact Knot for access to this endpoint. '500': description: Internal server error. content: application/json: schema: $ref: '#/components/schemas/Error' examples: InternalServerError: summary: Unexpected server error value: message: Server Error components: schemas: Error: type: object properties: error_type: type: string description: Type of error. enum: - INVALID_INPUT - INVALID_REQUEST - USER_ERROR - SESSION_ERROR - MERCHANT_ACCOUNT_ERROR - MERCHANT_ERROR - SUBSCRIPTION_ERROR - TRANSACTION_ERROR - CART_ERROR example: INVALID_REQUEST error_code: type: string description: Error code. enum: - INVALID_API_KEYS - INVALID_FIELD - INVALID_JWE - INVALID_CURSOR_FORMAT - USER_NOT_FOUND - MERCHANT_ACCOUNT_NOT_FOUND - MERCHANT_ACCOUNT_DISCONNECTED - SESSION_NOT_FOUND - EXTEND_NOT_SUPPORTED - MERCHANT_UNAVAILABLE - NO_ACCESS - TRANSACTION_NOT_FOUND - NO_TRANSACTIONS - SUBSCRIPTION_NOT_FOUND - ONGOING_OPERATION - CART_NOT_FOUND - FULFILLMENT_NOT_FOUND example: INVALID_FIELD error_message: type: string description: Detailed error message. example: The limit may not be greater than 10. securitySchemes: basicAuth: type: http scheme: basic description: >- Basic authentication header of the form `Basic `, where `` is the base64-encoded string `username:password`. Use your `client_id` as the `username` and your `secret` as the `password` value. ````