> ## Documentation Index > Fetch the complete documentation index at: https://cobo.com/products/agentic-wallet/manual/llms.txt > Use this file to discover all available pages before exploring further. # Create payment > Signs and submits a payment on behalf of the specified wallet using either the x402 or MPP protocol. **Protocol selection** (required `protocol` field in the request body): - `x402`: provide the `x402_payment_required` challenge object received from the payee server. - `mpp`: provide the `mpp_www_authenticate` challenge string and, optionally, an `mpp_session` token. **Idempotency**: if you supply a `request_id`, the endpoint checks for a previously completed transaction with the same `request_id` for this wallet. When a match is found the original result is returned immediately (`idempotent: true`) together with the original response headers (`retry_headers`) so you can replay the HTTP payment call without re-signing. The wallet must be active (non-archived) and your principal must hold the `WALLET_TRANSFER` permission for the target wallet. ## OpenAPI ````yaml post /api/v1/wallets/{wallet_uuid}/payment openapi: 3.1.0 info: title: Cobo Agentic Wallet Service description: Unified wallet engine for human and agent principals version: 1.3.0 servers: [] security: [] paths: /api/v1/wallets/{wallet_uuid}/payment: post: tags: - Transactions summary: Create payment description: >- Signs and submits a payment on behalf of the specified wallet using either the x402 or MPP protocol. **Protocol selection** (required `protocol` field in the request body): - `x402`: provide the `x402_payment_required` challenge object received from the payee server. - `mpp`: provide the `mpp_www_authenticate` challenge string and, optionally, an `mpp_session` token. **Idempotency**: if you supply a `request_id`, the endpoint checks for a previously completed transaction with the same `request_id` for this wallet. When a match is found the original result is returned immediately (`idempotent: true`) together with the original response headers (`retry_headers`) so you can replay the HTTP payment call without re-signing. The wallet must be active (non-archived) and your principal must hold the `WALLET_TRANSFER` permission for the target wallet. operationId: payment parameters: - name: wallet_uuid in: path required: true schema: type: string format: uuid description: >- UUID of the wallet to sign and submit the payment from. Obtain this value from the wallet creation or list-wallets response. The wallet must be active (not archived). title: Wallet Uuid description: >- UUID of the wallet to sign and submit the payment from. Obtain this value from the wallet creation or list-wallets response. The wallet must be active (not archived). - name: X-API-Key in: header required: false schema: title: X-Api-Key type: string nullable: true requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/PaymentCreate' responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/StandardResponse_PaymentResult_' '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/WrappedValidationError' components: schemas: PaymentCreate: properties: protocol: $ref: '#/components/schemas/PaymentProtocol' description: 'Payment protocol: ''x402'' or ''mpp''' request_id: title: Request Id description: Idempotency key type: string maxLength: 255 nullable: true x402_payment_required: title: X402 Payment Required description: Base64-encoded JSON from Payment-Required header type: string nullable: true mpp_www_authenticate: title: Mpp Www Authenticate description: WWW-Authenticate header raw value type: string nullable: true mpp_session: $ref: '#/components/schemas/MppSessionParams' description: Session parameters for MPP session actions (open/voucher/close) nullable: true type: object required: - protocol title: PaymentCreate description: |- Unified payment request. Protocol-specific fields are prefixed with protocol name (x402_ / mpp_). StandardResponse_PaymentResult_: properties: success: type: boolean title: Success default: true result: $ref: '#/components/schemas/PaymentResult' suggestion: type: string title: Suggestion default: '' message: type: string title: Message default: '' meta: $ref: '#/components/schemas/PaginationMeta' nullable: true type: object required: - result title: StandardResponse[PaymentResult] WrappedValidationError: title: WrappedValidationError type: object required: - success - error properties: success: type: boolean const: false default: false title: Success error: type: object title: Error required: - detail properties: detail: type: array title: Detail items: $ref: '#/components/schemas/ValidationError' PaymentProtocol: type: string enum: - x402 - mpp title: PaymentProtocol description: Supported payment protocols. MppSessionParams: properties: action: $ref: '#/components/schemas/MppSessionAction' description: >- Session action: 'open' | 'voucher' | 'close' | 'request_close' | 'withdraw' salt: title: Salt description: Random salt for session open (hex string) type: string nullable: true deposit: title: Deposit description: Deposit amount for session open (raw token units) type: string nullable: true channel_id: title: Channel Id description: >- Payment channel identifier, required for voucher, close, request_close, and withdraw actions. type: string nullable: true cumulative_amount: title: Cumulative Amount description: >- Cumulative total amount paid so far in this channel, expressed in raw token units. Required for voucher actions. type: string nullable: true payer_address: title: Payer Address description: >- On-chain address of the payer who opened the payment channel. Required for voucher/close actions. type: string nullable: true challenge_cache: $ref: '#/components/schemas/MppChallenge' description: Cached challenge for voucher/close (no 402 re-negotiation) nullable: true type: object required: - action title: MppSessionParams description: >- Parameters for MPP session actions (open / voucher / close / request_close / withdraw). PaymentResult: properties: id: title: Id description: Unique identifier assigned to this payment record. type: string format: uuid nullable: true idempotent: type: boolean title: Idempotent description: >- True if this result was served from a cached response for a previously processed request_id; false if it was freshly processed. default: false request_id: title: Request Id description: Idempotency key echoed back from the original payment request. type: string nullable: true protocol: $ref: '#/components/schemas/PaymentProtocol' description: '''x402'' or ''mpp''' status: type: string title: Status description: completed / submitted / failed retry_headers: additionalProperties: type: string type: object title: Retry Headers description: >- Headers to set when retrying the original request. x402: {'PAYMENT-SIGNATURE': '...'}. MPP: {'Authorization': 'Payment '}. mpp_session_info: $ref: '#/components/schemas/MppSessionInfo' description: >- MPP session details populated only when the action is 'open'. Null for all other actions. nullable: true tx_hash: title: Tx Hash description: >- On-chain transaction hash returned for request_close and withdraw actions. Null for all other actions. type: string nullable: true type: object required: - protocol - status title: PaymentResult description: |- Unified payment result. CLI uses retry_headers to retry the original request. PaginationMeta: properties: total: title: Total type: integer nullable: true offset: title: Offset type: integer nullable: true limit: title: Limit type: integer nullable: true has_more: title: Has More type: boolean nullable: true after: title: After type: string nullable: true before: title: Before type: string nullable: true type: object title: PaginationMeta description: |- Pagination metadata for list responses. Supports both legacy offset-based and cursor-based pagination. Cursor fields (``has_more``, ``after``, ``before``) are populated for cursor-paginated endpoints. Legacy fields (``offset``, ``limit``) are populated when the caller uses the deprecated ``offset`` parameter. ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: type: string title: Error Type input: title: Input ctx: type: object title: Context type: object required: - loc - msg - type title: ValidationError MppSessionAction: type: string enum: - open - voucher - close - request_close - withdraw title: MppSessionAction description: MPP session action types. MppChallenge: properties: id: type: string title: Id realm: type: string title: Realm method: type: string title: Method intent: type: string title: Intent request: additionalProperties: true type: object title: Request request_b64: type: string title: Request B64 expires: type: string title: Expires default: '' description: type: string title: Description default: '' type: object required: - id - realm - method - intent - request - request_b64 title: MppChallenge description: Parsed MPP Payment challenge from WWW-Authenticate header. MppSessionInfo: properties: payer_address: type: string title: Payer Address description: On-chain address of the payer who opened the payment channel. chain_id: type: string title: Chain Id description: >- Cobo chain ID on which the payment channel was opened (e.g. 'ETH' for Ethereum mainnet). Call the List supported chains operation (GET /metadata/chains) to retrieve all supported chain IDs. channel_id: title: Channel Id description: >- Unique identifier of the opened payment channel. May be absent if the channel is not yet confirmed on-chain. type: string nullable: true type: object required: - payer_address - chain_id title: MppSessionInfo description: >- MPP session details returned by the backend after a successful channel open action. ````