> ## Documentation Index > Fetch the complete documentation index at: https://docs.neynar.com/llms.txt > Use this file to discover all available pages before exploring further. # Create x402 signature > Create a signature for a given x402 resource using the specified wallet. ## Create x402 Signature ## Node.js SDK 🔗 **SDK Method:** [createX402Signature](/nodejs-sdk/onchain-apis/createX402Signature) Use this API endpoint with the Neynar Node.js SDK for typed responses and better developer experience. ## OpenAPI ````yaml post /v2/signature/x402/ openapi: 3.0.4 info: contact: email: team@neynar.com name: Neynar url: https://neynar.com/ description: >- The Neynar API allows you to interact with the Farcaster protocol among other things. See the [Neynar docs](https://docs.neynar.com/reference) for more details. title: Neynar API version: 3.173.0 servers: - url: https://api.neynar.com security: - ApiKeyAuth: [] tags: - description: Operations related to user externalDocs: description: More info about user url: https://docs.neynar.com/reference/user-operations name: User - description: Operations related to signer externalDocs: description: More info about signer url: https://docs.neynar.com/reference/signer-operations name: Signer - description: Operations related to cast externalDocs: description: More info about cast url: https://docs.neynar.com/reference/cast-operations name: Cast - description: Operations related to feed externalDocs: description: More info about feed url: https://docs.neynar.com/reference/feed-operations name: Feed - description: Operations related to reaction externalDocs: description: More info about reaction url: https://docs.neynar.com/reference/reaction-operations name: Reaction - description: Operations related to notifications externalDocs: description: More info about notifications url: https://docs.neynar.com/reference/notifications-operations name: Notifications - description: Operations related to channels externalDocs: description: More info about channels url: https://docs.neynar.com/reference/channel-operations name: Channel - description: Operations related to follows externalDocs: description: More info about follows url: https://docs.neynar.com/reference/follows-operations name: Follows - description: Operations related to storage externalDocs: description: More info about storage url: https://docs.neynar.com/reference/storage-operations name: Storage - description: Operations related to mini apps name: Frame - description: Operations for building AI agents name: Agents - description: Operations related to fname name: fname - description: Operations related to a webhook name: Webhook - description: >- Securely communicate and perform actions on behalf of users across different apps externalDocs: description: More info about farcaster actions url: https://docs.neynar.com/docs/farcaster-actions-spec name: Action - description: Operations related to a subscriptions name: Subscribers - description: Operations related to a mute name: Mute - description: Operations related to a block name: Block - description: Operations related to a ban name: Ban - description: Operations related to onchain data name: Onchain - description: Operations related to login name: Login - description: Operations related to retrieving metrics name: Metrics - description: Operations related to mini app host notifications externalDocs: description: More info about mini app host notifications url: https://docs.neynar.com/docs/app-host-notifications name: App Host paths: /v2/signature/x402/: post: tags: - Onchain summary: Create x402 signature description: Create a signature for a given x402 resource using the specified wallet. operationId: create-x402-signature parameters: - $ref: '#/components/parameters/WalletIdHeader' - in: header name: x-api-key required: true schema: type: string requestBody: content: application/json: schema: properties: payment_requirements: properties: accepts: items: properties: asset: description: Ethereum address example: '0x5a927ac639636e534b678e81768ca19e2c6280b7' pattern: ^0x[a-fA-F0-9]{40}$ title: EthAddress type: string description: type: string extra: additionalProperties: {} nullable: true type: object maxAmountRequired: type: string maxTimeoutSeconds: type: number mimeType: type: string network: enum: - base - base-sepolia type: string outputSchema: additionalProperties: {} nullable: true type: object payTo: description: Ethereum address example: '0x5a927ac639636e534b678e81768ca19e2c6280b7' pattern: ^0x[a-fA-F0-9]{40}$ title: EthAddress type: string resource: format: uri type: string scheme: enum: - exact type: string required: - scheme - network - maxAmountRequired - asset - payTo - resource - description - maxTimeoutSeconds type: object minItems: 1 type: array x402Version: enum: - 1 type: number required: - x402Version - accepts type: object required: - payment_requirements type: object required: true responses: '200': content: application/json: schema: properties: network: enum: - base - base-sepolia type: string payload: properties: authorization: properties: from: $ref: '#/components/schemas/EthAddress' nonce: pattern: ^0x[a-fA-F0-9]{64}$ type: string to: $ref: '#/components/schemas/EthAddress' validAfter: type: string validBefore: type: string value: type: string required: - from - to - value - validAfter - validBefore - nonce type: object signature: pattern: ^0x[a-fA-F0-9]{130}$ type: string required: - signature - authorization type: object scheme: enum: - exact type: string x402Version: enum: - 1 type: number required: - x402Version - scheme - network - payload type: object description: Success '400': content: application/json: schema: $ref: '#/components/schemas/ErrorRes' description: Bad Request '401': content: application/json: schema: $ref: '#/components/schemas/ErrorRes' description: Unauthorized '403': content: application/json: schema: $ref: '#/components/schemas/ErrorRes' description: Forbidden '500': content: application/json: schema: $ref: '#/components/schemas/ErrorRes' description: Server Error externalDocs: url: https://docs.neynar.com/reference/create-x402-signature components: parameters: WalletIdHeader: description: Wallet ID to use for transactions in: header name: x-wallet-id required: true schema: type: string x-is-global-header: true schemas: EthAddress: description: Ethereum address example: '0x5a927ac639636e534b678e81768ca19e2c6280b7' pattern: ^0x[a-fA-F0-9]{40}$ title: EthAddress type: string ErrorRes: description: Details for the error response properties: code: type: string message: type: string property: type: string status: format: int32 type: integer required: - message title: ErrorRes type: object securitySchemes: ApiKeyAuth: description: API key to authorize requests in: header name: x-api-key type: apiKey x-default: NEYNAR_API_DOCS ````