> ## 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. # Retrieve a user operation > Retrieve an existing user operation. ## OpenAPI ````yaml openapi/buidl-wallets.yaml get /v1/w3s/buidl/userOps/{id} openapi: 3.0.3 info: description: Modular Wallets API documentation. title: Modular Wallets version: '1.0' servers: - url: https://api.circle.com security: - BearerAuth: [] tags: - name: Transfers - name: UserOps - name: Wallets paths: /v1/w3s/buidl/userOps/{id}: get: tags: - UserOps summary: Retrieve a user operation description: Retrieve an existing user operation. operationId: getUserOp parameters: - $ref: '#/components/parameters/Id' - $ref: '#/components/parameters/XRequestId' responses: '200': description: User operation retrieved successfully. content: application/json: schema: $ref: '#/components/schemas/UserOpId' headers: X-Request-Id: $ref: '#/components/headers/XRequestId' '400': $ref: '#/components/responses/DefaultError' '401': $ref: '#/components/responses/NotAuthorized' security: - BearerAuth: [] components: parameters: Id: name: id description: The universally unique identifier of the resource. in: path required: true schema: type: string format: uuid example: b3d9d2d5-4c12-4946-a09d-953e82fae2b0 XRequestId: name: X-Request-Id in: header description: > Developer-provided identifier for this request, used for tracing requests in Wallets API logs and the Developer Console, and when communicating with Circle Support. **Must be a UUID to appear in logs.** Non-UUID values are accepted by the API but are ignored by logging and tracing systems. schema: $ref: '#/components/schemas/XRequestId' schemas: UserOpId: title: UserOpResponse type: object required: - data properties: data: type: object required: - userOperation properties: userOperation: $ref: '#/components/schemas/UserOp' XRequestId: type: string format: uuid description: >- A unique identifier, which can be helpful for identifying a request when communicating with Circle support. example: 2adba88e-9d63-44bc-b975-9b6ae3440dde UserOp: title: UserOp type: object required: - id - blockchain - state - userOpHash - userOperation properties: id: $ref: '#/components/schemas/Id' refId: $ref: '#/components/schemas/ReferenceId' actualGasCost: type: string description: Actual gas cost of user operation. example: '0.0015584763706281' actualGasUsed: type: string description: Actual gas used of user operation. example: '182385' blockDate: $ref: '#/components/schemas/BlockDate' blockHash: $ref: '#/components/schemas/BlockHash' blockHeight: $ref: '#/components/schemas/BlockHeight' blockchain: $ref: '#/components/schemas/Blockchain' errorReason: $ref: '#/components/schemas/UserOpErrorReason' revertReason: type: string description: On-chain failed revert reason of user operation. state: $ref: '#/components/schemas/UserOpState' to: $ref: '#/components/schemas/Address' description: Address of user operation executed with. txHash: $ref: '#/components/schemas/TxHash' userOpHash: $ref: '#/components/schemas/UserOpHash' userOperation: $ref: '#/components/schemas/UserOperation' createDate: $ref: '#/components/schemas/CreateDate' updateDate: $ref: '#/components/schemas/UpdateDate' Error: title: Error type: object required: - code - message properties: code: type: integer description: Code that corresponds to the error. message: type: string description: Message that describes the error. Id: type: string format: uuid description: System-generated unique identifier of the resource. example: c4d1da72-111e-4d52-bdbf-2e74a2d803d5 ReferenceId: type: string description: >- Optional user-defined reference identifier for the wallet. Not used by Circle for wallet functionality. Used for internal tracking or associating wallets with entities in your own systems (for example, a customer or account ID). example: customer_12345 BlockDate: title: BlockDate type: string format: date-time description: Date and time of block, in ISO-8601 UTC format. example: '2023-01-01T12:04:05Z' BlockHash: title: BlockHash type: string description: Blockchain generated identifier of block. example: '0x2eb19fd02850ff963efefbaa71dbcd4acb41a9c261c4f8961979db1b56d48704' BlockHeight: title: BlockHeight type: integer description: Blockchain height of block. example: 123456 Blockchain: title: Blockchain type: string description: Blockchain network of resource. enum: - ETH - ETH-SEPOLIA - MATIC - MATIC-AMOY - ARB - ARB-SEPOLIA - UNI - UNI-SEPOLIA - BASE - BASE-SEPOLIA - OP - OP-SEPOLIA - AVAX - AVAX-FUJI - ARC-TESTNET - MONAD - MONAD-TESTNET example: MATIC-AMOY UserOpErrorReason: title: ErrorReason type: string description: Error reason of failed user operation. enum: - FAILED_ON_CHAIN - FAILED_REPLACED example: FAILED_REPLACED UserOpState: title: State type: string description: State of user operation. enum: - SENT - CONFIRMED - COMPLETE - FAILED example: COMPLETE Address: title: Address description: > Blockchain generated unique identifier, associated with wallet (account), smart contract or other blockchain objects. type: string example: '0x4b6c0b0078b63f881503e7fd3a9a1061065db242' TxHash: title: TxHash type: string description: Blockchain generated identifier of transaction. example: '0x4a25cc5e661d8504b59c5f38ba93f010e8518966f00e2ceda7955c4b8621357d' UserOpHash: title: UserOpHash type: string description: Generated identifier of user operation. example: '0x54d3cccda6ffa503bc1e554937fe67818b6ca1a5a05c7e66ebfa32bf27520152' UserOperation: title: UserOperation type: object required: - callData - nonce - sender properties: callData: type: string callGasLimit: type: string factory: type: string factoryData: type: string initCode: type: string maxFeePerGas: type: string maxPriorityFeePerGas: type: string nonce: type: string paymaster: type: string paymasterAndData: type: string paymasterData: type: string paymasterPostOpGasLimit: type: string paymasterVerificationGasLimit: type: string preVerificationGas: type: string sender: type: string signature: type: string verificationGasLimit: type: string CreateDate: type: string format: date-time description: Date and time the resource was created, in ISO-8601 UTC format. example: '2023-01-01T12:04:05Z' UpdateDate: type: string format: date-time description: Date and time the resource was last updated, in ISO-8601 UTC format. example: '2023-01-01T12:04:05Z' headers: XRequestId: description: > Developer-provided header parameter or Circle-generated universally unique identifier (UUID v4). Useful for identifying a specific request when communicating with Circle Support. schema: $ref: '#/components/schemas/XRequestId' responses: DefaultError: content: application/json: schema: $ref: '#/components/schemas/Error' description: Error response headers: X-Request-Id: $ref: '#/components/headers/XRequestId' NotAuthorized: content: application/json: schema: type: object title: NotAuthorizedResponse required: - code - message properties: code: type: integer description: Code that corresponds to the error. message: type: string description: Message that describes the error. example: code: 401 message: Malformed authorization. description: >- Request has not been applied because it lacks valid authentication credentials. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: PREFIX:ID:SECRET description: >- Circle's API Keys are formatted in the following structure "PREFIX:ID:SECRET". All three parts are required to make a successful request. ````