> ## Documentation Index > Fetch the complete documentation index at: https://developers.circle.com/llms.txt > Use this file to discover all available pages before exploring further. # Open a passkey registration session > Creates a short-lived registration session (10-minute TTL) that coordinates WebAuthn passkey enrollment for an end user. Pass the returned `frameToken` to the DAA web SDK's `sca.enroll` method to run the enrollment ceremony. ## OpenAPI ````yaml openapi/accounts.yaml post /v1/accounts/passkeys/registrations openapi: 3.1.0 info: version: 1.0.0 title: Accounts (Stablecoin) API description: > Circle's Accounts API provides endpoints for managing stablecoin accounts -- including transfers, withdrawals, deposits, wire and ACH bank accounts, and blockchain addresses. An **Account** is a general representation of a ledger or custody object that holds balances. It can be a business account, a stablecoin account ledger for an end user, an extra sub-ledger, or any future custody solution. license: name: Circle License url: https://circle.com/terms servers: - url: https://api-sandbox.circle.com - url: https://api.circle.com security: [] tags: - name: Accounts description: Manage accounts. - name: Account Groups description: Manage custody account groups and their memberships. - name: Limits description: View effective account limits and current usage. - name: Transfers description: Manage account transfers. - name: Transactions description: | Get a unified, customer-friendly view of account transaction activity. - name: Wires description: Manage account bank accounts for wire transfers. - name: Deposits description: Get information on account bank deposits. - name: Withdrawals description: Manage account bank withdrawals (fiat offramp). - name: ACH description: Manage account bank accounts for ACH transfers. - name: Deposit Addresses description: Manage account deposit addresses. - name: Recipient Addresses description: Manage account recipient addresses used for transfers. - name: Passkeys description: > Manage WebAuthn passkeys and Strong Customer Authentication (SCA) challenges for end users. - name: Webhook Subscriptions description: Manage subscriptions to Digital Asset Accounts webhook notifications. paths: /v1/accounts/passkeys/registrations: post: tags: - Passkeys summary: Open a passkey registration session description: > Creates a short-lived registration session (10-minute TTL) that coordinates WebAuthn passkey enrollment for an end user. Pass the returned `frameToken` to the DAA web SDK's `sca.enroll` method to run the enrollment ceremony. operationId: openPasskeyRegistration requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/PasskeyRegistrationRequest' responses: '201': description: Successfully opened a passkey registration session. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/OpenPasskeyRegistrationResponse' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/NotAuthorized' '409': description: > The `idempotencyKey` was already used for a different `clientEntityId` or `spcCapable` value. content: application/json: schema: $ref: '#/components/schemas/Error' '500': $ref: '#/components/responses/InternalServerError' security: - bearerAuth: [] components: schemas: PasskeyRegistrationRequest: type: object required: - clientEntityId - idempotencyKey properties: clientEntityId: type: string description: The end-user identifier to enroll. example: entity_01234567890abcdef idempotencyKey: type: string format: uuid description: > A unique key for this registration session. Replaying the same key for the same `clientEntityId` and `spcCapable` returns the original session unchanged. Using the same key for a different `clientEntityId` or `spcCapable` value returns `409`. example: 550e8400-e29b-41d4-a716-446655440000 spcCapable: type: boolean default: false description: > Whether this credential should be marked as eligible for Secure Payment Confirmation (SPC). Defaults to `false`. This flag is recorded permanently at enrollment and cannot be changed later. OpenPasskeyRegistrationResponse: type: object properties: data: type: object properties: registrationId: type: string format: uuid description: >- Use this ID to complete registration via `POST /v1/accounts/passkeys`. example: a1b2c3d4-e5f6-7890-ab12-cdef34567890 frameToken: type: string description: > Opaque token that authorizes the enrollment ceremony iframe. Pass it to the DAA web SDK's `sca.enroll` method immediately. Expires after 10 minutes. Re-sending this request with the same `idempotencyKey` rotates the token and invalidates any token already delivered to the frontend. example: k74ia-AcnTzXtBdxnbVqn1IBpVUXBbhGiGxQkGD386A expiresAt: type: string format: date-time description: When the registration session expires. example: '2026-09-24T12:10:00Z' required: - registrationId - frameToken - expiresAt Error: type: object required: - code - message properties: code: type: integer description: > Circle internal status code from the platform `CoreStatusCode` enum (and its domain-specific extensions). **This is not the HTTP status code** — `-1` is the catch-all unknown error, `1`/`2` indicate API parameter problems, `3` is forbidden, `4` is unauthorized, and larger values identify domain-specific failures. Consumers should rely on the HTTP status line for transport-level error class and on this field for the specific Circle error case. example: 2 message: type: string description: >- Internal error message; suitable for logging but not for end-user display. example: API parameter invalid. externalMessage: type: string description: > End-user-displayable error message. Present when the server has generated a customer-facing variant for this error; omitted otherwise. example: The provided amount exceeds the maximum allowed. errors: type: array description: Additional request-field validation errors, when available. items: $ref: '#/components/schemas/ErrorDetail' XRequestId: type: string format: uuid example: 2adba88e-9d63-44bc-b975-9b6ae3440dde ErrorDetail: type: object required: - error - message properties: error: type: string description: Machine-readable error identifier. example: invalid_value location: type: string description: Query parameter or request field that caused the error. example: assetType message: type: string description: Human-readable description of the specific error. example: The operation and assetType combination is invalid. headers: XRequestId: description: > Circle-generated universally unique identifier (UUID v4). Useful for identifying a specific request when communicating with Circle Support. schema: $ref: '#/components/schemas/XRequestId' responses: BadRequest: description: The request cannot be processed due to a client error. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: code: 2 message: API parameter invalid. NotAuthorized: description: >- The request has not been applied because it lacks valid authentication credentials. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: code: 4 message: Unauthorized. InternalServerError: description: >- The server encountered an unexpected condition that prevented it from fulfilling the request. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: code: -1 message: 'Something went wrong. errId: 1f0b0c455e40f753f07b4f0ae6abd4b4' securitySchemes: bearerAuth: type: http scheme: bearer ````