> ## 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. # Get a notification signature public key > Get the public key and algorithm used to digitally sign webhook notifications. Verifying the digital signature ensures the notification came from Circle. In the headers of each webhook, you can find: - `X-Circle-Signature`: the digital signature generated by Circle. - `X-Circle-Key-Id`: the UUID used as the `id` path parameter to retrieve the relevant public key. ## OpenAPI ````yaml openapi/accounts.yaml get /v2/notifications/publicKey/{id} 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: Webhook Subscriptions description: Manage subscriptions to Digital Asset Accounts webhook notifications. paths: /v2/notifications/publicKey/{id}: get: tags: - Webhook Subscriptions summary: Get a notification signature public key description: > Get the public key and algorithm used to digitally sign webhook notifications. Verifying the digital signature ensures the notification came from Circle. In the headers of each webhook, you can find: - `X-Circle-Signature`: the digital signature generated by Circle. - `X-Circle-Key-Id`: the UUID used as the `id` path parameter to retrieve the relevant public key. operationId: getNotificationSignature parameters: - $ref: '#/components/parameters/IdPath' - $ref: '#/components/parameters/XRequestId' responses: '200': description: Successfully retrieved a notification signature public key. content: application/json: schema: $ref: '#/components/schemas/NotificationSignaturePublicKeyResponse' headers: X-Request-Id: $ref: '#/components/headers/XRequestId' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/NotAuthorized' '404': $ref: '#/components/responses/NotFound' '500': $ref: '#/components/responses/InternalServerError' security: - bearerAuth: [] components: parameters: IdPath: name: id description: Universally unique identifier (UUID v4) of a resource. in: path required: true schema: type: string format: uuid example: b3d9d2d5-4c12-4946-a09d-953e82fae2b0 XRequestId: name: X-Request-Id description: >- Developer-provided parameter used to identify this request. Useful when communicating with Circle Support. in: header schema: $ref: '#/components/schemas/XRequestId' schemas: NotificationSignaturePublicKeyResponse: title: NotificationSignaturePublicKeyResponse type: object properties: data: type: object required: - id - algorithm - publicKey - createDate properties: id: type: string format: uuid example: 09379bc1-4871-45ad-8b8b-8027795df70d algorithm: type: string example: ECDSA_SHA_256 publicKey: type: string example: >- QFkwewylAoZIzj0CBQYIKoZIzj0DAQcDQgAEEext6d7AimvYFDAKBwsUsGXrhqmRHNPYum7V/BwfvJLmJeSMe2V0b9eWKPuFxAEH8HCY/MSZdBI+q/E6IdPnSg== createDate: type: string format: date-time example: '2026-06-01T18:18:06.931Z' XRequestId: type: string format: uuid example: 2adba88e-9d63-44bc-b975-9b6ae3440dde 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' 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. NotFound: description: The specified resource was not found. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: code: 404 message: Not found. 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 ````