openapi: 3.1.0 info: title: Circle Web3 Services (W3S) — Developer-Controlled Wallets NFTs Transactions API description: 'Circle''s Web3 Services API for developer-controlled programmable wallets, wallet sets, signing, transactions, tokens, and NFTs. This is a best-effort partial spec derived from Circle''s published OpenAPI at https://developers.circle.com/openapi/developer-controlled-wallets.yaml.' version: '2026-05-23' contact: name: Circle Developer Support url: https://developers.circle.com/ license: name: Proprietary servers: - url: https://api.circle.com description: Production security: - BearerAuth: [] tags: - name: Transactions paths: /v1/w3s/transactions: get: tags: - Transactions summary: List transactions operationId: listTransactions responses: '200': description: A list of transactions /v1/w3s/transactions/{id}: parameters: - $ref: '#/components/parameters/ResourceId' get: tags: - Transactions summary: Get transaction operationId: getTransaction responses: '200': description: Transaction details /v1/w3s/transactions/lowestNonceTransaction: get: tags: - Transactions summary: Get lowest nonce transaction operationId: getLowestNonceTransaction responses: '200': description: Transaction details /v1/w3s/developer/transactions/feeParameters: get: tags: - Transactions summary: Get fee parameters operationId: getFeeParameters responses: '200': description: Fee parameters /v1/w3s/developer/transactions/transfer: post: tags: - Transactions summary: Create a transfer transaction operationId: createTransferTransaction responses: '201': description: Transfer submitted /v1/w3s/transactions/transfer/estimateFee: post: tags: - Transactions summary: Estimate transfer fee operationId: estimateTransferFee responses: '200': description: Fee estimate /v1/w3s/transactions/contractExecution/estimateFee: post: tags: - Transactions summary: Estimate contract-execution fee operationId: estimateContractExecutionFee responses: '200': description: Fee estimate /v1/w3s/transactions/validateAddress: post: tags: - Transactions summary: Validate a blockchain address operationId: validateAddress responses: '200': description: Validation result /v1/w3s/developer/transactions/contractExecution: post: tags: - Transactions summary: Create contract-execution transaction operationId: createContractExecution responses: '201': description: Contract execution submitted /v1/w3s/developer/transactions/walletUpgrade: post: tags: - Transactions summary: Create wallet-upgrade transaction operationId: createWalletUpgrade responses: '201': description: Wallet upgrade submitted /v1/w3s/developer/transactions/{id}/cancel: parameters: - $ref: '#/components/parameters/ResourceId' post: tags: - Transactions summary: Cancel a transaction operationId: cancelTransaction responses: '200': description: Cancel submitted /v1/w3s/developer/transactions/{id}/accelerate: parameters: - $ref: '#/components/parameters/ResourceId' post: tags: - Transactions summary: Accelerate a transaction operationId: accelerateTransaction responses: '200': description: Accelerate submitted components: parameters: ResourceId: name: id in: path required: true description: Resource identifier (UUID). schema: type: string format: uuid securitySchemes: BearerAuth: type: http scheme: bearer description: Circle API key, formatted as `PREFIX:ID:SECRET`, supplied as Bearer token.