> ## Documentation Index > Fetch the complete documentation index at: https://docs.crossmint.com/llms.txt > Use this file to discover all available pages before exploring further. # Create Signature > Creates a new signature for signing messages or typed data. **API scope required**: `wallets:signatures.create` ## OpenAPI ````yaml post /2025-06-09/wallets/{walletLocator}/signatures openapi: 3.0.0 info: title: Crossmint Wallets API description: Crossmint Wallets API version: 1.0.0 contact: name: Crossmint Support url: https://www.crossmint.com email: support@crossmint.com servers: - url: https://staging.crossmint.com/api description: Staging environment (testnets) - url: https://www.crossmint.com/api description: Production environment (mainnets) security: [] tags: [] paths: /2025-06-09/wallets/{walletLocator}/signatures: post: summary: Create Signature description: |- Creates a new signature for signing messages or typed data. **API scope required**: `wallets:signatures.create` operationId: WalletsV2025Controller-createSignatureRequest-2 parameters: - name: X-API-KEY in: header description: API key required for authentication required: true schema: type: string - name: walletLocator required: true in: path description: >- A wallet locator can be of the format: - `` - `email::[:][:alias:]` (walletType defaults to 'smart') - `userId::[:][:alias:]` (white label user example) - `phoneNumber::[:][:alias:]` - `twitter::[:][:alias:]` - `x::[:][:alias:]` - `me:[:][:alias:]` (Use when calling from the client side with a client API key) - `chainType[:]:alias:` schema: type: string - name: x-idempotency-key required: false in: header description: Unique key to prevent duplicate signature creation schema: type: string requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateSignatureV2025DTO' responses: '201': description: The signature has been successfully created. content: application/json: schema: $ref: '#/components/schemas/WalletsSignatureV2025ResponseDTO' '400': description: Returns an error if the signature type is not supported content: application/json: schema: $ref: '#/components/schemas/WalletV1Alpha2ErrorDTO' '404': description: Returns an error if a wallet with the specified locator not found content: application/json: schema: $ref: '#/components/schemas/WalletV1Alpha2ErrorDTO' components: schemas: CreateSignatureV2025DTO: oneOf: - type: object properties: type: type: string enum: - message params: type: object properties: message: type: string description: The message in plain text to sign signer: description: >- The locator for the signer who will submit this signature. Defaults to the wallet's admin signer. type: string title: Signer Locator example: external-wallet:0x1234567890123456789012345678901234567890 chain: description: >- The chain on which the signature will be submitted. Required for EVM wallets, optional for others. type: string enum: - arbitrum-sepolia - arc-testnet - avalanche-fuji - curtis - base-goerli - base-sepolia - bsc-testnet - chiliz-spicy-testnet - coti-testnet - ethereum-goerli - ethereum-sepolia - hedera-testnet - hypersonic-testnet - lightlink-pegasus - mantle-sepolia - optimism-goerli - optimism-sepolia - polygon-amoy - polygon-mumbai - crossmint-private-testnet-ethereum - crossmint-private-testnet-polygon - rari-testnet - scroll-sepolia - sei-atlantic-2-testnet - shape-sepolia - skale-nebula-testnet - soneium-minato-testnet - space-testnet - story-testnet - verify-testnet - viction-testnet - xai-sepolia-testnet - zkatana - zkyoto - zora-goerli - zora-sepolia - mode-sepolia - u2u-nebulas - zenchain-testnet - abstract-testnet - world-chain-sepolia - plume-testnet - flow-testnet - tempo-testnet - ethereum - polygon - bsc - optimism - arbitrum - base - zora - arbitrumnova - astar-zkevm - apechain - hedera - coti - lightlink - mantle - skale-nebula - sei-pacific-1 - chiliz - avalanche - xai - shape - rari - scroll - viction - mode - space - soneium - story - u2u-solaris - abstract - world-chain - plume - flow - tempo required: - message description: Parameters for a message signature required: - type - params title: Message Signature description: Parameters for a message signature - type: object properties: type: type: string enum: - typed-data params: type: object properties: typedData: type: object properties: domain: type: object properties: name: type: string version: type: string chainId: type: number verifyingContract: type: string description: The recipient address for this transaction call salt: type: string description: WebAuthn authenticator data as hex string required: - name - version - chainId - verifyingContract types: type: object additionalProperties: type: array items: type: object properties: name: type: string type: type: string required: - name - type primaryType: type: string message: type: object additionalProperties: true required: - domain - types - primaryType - message chain: type: string enum: - arbitrum-sepolia - arc-testnet - avalanche-fuji - curtis - base-goerli - base-sepolia - bsc-testnet - chiliz-spicy-testnet - coti-testnet - ethereum-goerli - ethereum-sepolia - hedera-testnet - hypersonic-testnet - lightlink-pegasus - mantle-sepolia - optimism-goerli - optimism-sepolia - polygon-amoy - polygon-mumbai - crossmint-private-testnet-ethereum - crossmint-private-testnet-polygon - rari-testnet - scroll-sepolia - sei-atlantic-2-testnet - shape-sepolia - skale-nebula-testnet - soneium-minato-testnet - space-testnet - story-testnet - verify-testnet - viction-testnet - xai-sepolia-testnet - zkatana - zkyoto - zora-goerli - zora-sepolia - mode-sepolia - u2u-nebulas - zenchain-testnet - abstract-testnet - world-chain-sepolia - plume-testnet - flow-testnet - tempo-testnet - ethereum - polygon - bsc - optimism - arbitrum - base - zora - arbitrumnova - astar-zkevm - apechain - hedera - coti - lightlink - mantle - skale-nebula - sei-pacific-1 - chiliz - avalanche - xai - shape - rari - scroll - viction - mode - space - soneium - story - u2u-solaris - abstract - world-chain - plume - flow - tempo description: The chain on which the signature will be submitted signer: description: The locator for the signer who will approve this signature type: string title: Signer Locator example: external-wallet:0x1234567890123456789012345678901234567890 isSmartWalletSignature: description: >- Whether the signature corresponds to the smart wallet or to the signer. If true, the signature will be wrapped with ERC6492. type: boolean required: - typedData - chain description: Parameters for a typed data signature required: - type - params title: Typed Data Signature description: Parameters for a typed data signature - type: object properties: type: type: string enum: - auth-entries params: type: object properties: authorizationEntries: type: string description: >- Base64-encoded XDR array of all authorization entries from the SEP-45 challenge (4-byte BE count prefix + concatenated entry XDR) signer: description: >- The locator for the signer who will approve this entry. Defaults to the wallet's admin signer. type: string title: Signer Locator example: external-wallet:0x1234567890123456789012345678901234567890 required: - authorizationEntries description: Parameters for signing Stellar authorization entries (SEP-45) required: - type - params title: Auth Entries Signature description: Parameters for signing Stellar authorization entries (SEP-45) description: >- Input schema for creating a new signature. The parameters vary based on the signature type. example: type: message params: message: Hello, world! signer: external-wallet:0xB17Ea8d34078424B9d7D126E444d5F2C3CC5c81E chain: ethereum WalletsSignatureV2025ResponseDTO: type: object properties: id: type: string description: Unique identifier for the signature type: type: string enum: - message - typed-data - auth-entries description: The type of signature chainType: type: string enum: - evm - solana - aptos - sui - stellar description: The blockchain type of the wallet walletType: type: string enum: - smart - mpc description: The wallet type (smart or mpc) status: type: string enum: - awaiting-approval - pending - failed - success description: Current status of the signature params: anyOf: - type: object properties: message: type: string description: The message in plain text to sign signer: description: >- The full signer object who will submit this signature. Defaults to the wallet's admin signer. oneOf: - type: object properties: type: type: string enum: - external-wallet address: type: string description: The address of the external wallet locator: type: string description: The locator of the external wallet signer required: - type - address - locator title: External Wallet Signer description: Full External Wallet signer object - type: object properties: type: type: string enum: - passkey id: type: string description: The ID of the passkey locator: type: string description: The locator of the passkey signer required: - type - id - locator title: Passkey Signer description: Full Passkey signer object - type: object properties: type: type: string enum: - api-key address: type: string description: The address of the api key locator: type: string description: The locator of the api key signer required: - type - address - locator title: API Key Signer description: Full API Key signer object - type: object properties: type: type: string enum: - device publicKey: type: object properties: x: type: string 'y': type: string required: - x - 'y' description: The p256 public key of the device signer locator: type: string description: The locator of the device signer name: description: Optional human-readable name for the device signer type: string required: - type - publicKey - locator title: Device Signer description: Full Device signer object - type: object properties: type: type: string enum: - email email: type: string format: email pattern: >- ^(?!\.)(?!.*\.\.)([A-Za-z0-9_'+\-\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\-]*\.)+[A-Za-z]{2,}$ locator: type: string required: - type - email - locator - type: object properties: type: type: string enum: - phone phone: type: string locator: type: string required: - type - phone - locator - type: object properties: type: type: string enum: - server address: type: string locator: type: string required: - type - address - locator chain: type: string enum: - arbitrum-sepolia - arc-testnet - avalanche-fuji - curtis - base-goerli - base-sepolia - bsc-testnet - chiliz-spicy-testnet - coti-testnet - ethereum-goerli - ethereum-sepolia - hedera-testnet - hypersonic-testnet - lightlink-pegasus - mantle-sepolia - optimism-goerli - optimism-sepolia - polygon-amoy - polygon-mumbai - crossmint-private-testnet-ethereum - crossmint-private-testnet-polygon - rari-testnet - scroll-sepolia - sei-atlantic-2-testnet - shape-sepolia - skale-nebula-testnet - soneium-minato-testnet - space-testnet - story-testnet - verify-testnet - viction-testnet - xai-sepolia-testnet - zkatana - zkyoto - zora-goerli - zora-sepolia - mode-sepolia - u2u-nebulas - zenchain-testnet - abstract-testnet - world-chain-sepolia - plume-testnet - flow-testnet - tempo-testnet - ethereum - polygon - bsc - optimism - arbitrum - base - zora - arbitrumnova - astar-zkevm - apechain - hedera - coti - lightlink - mantle - skale-nebula - sei-pacific-1 - chiliz - avalanche - xai - shape - rari - scroll - viction - mode - space - soneium - story - u2u-solaris - abstract - world-chain - plume - flow - tempo description: The chain on which the signature will be submitted required: - message title: Message signature parameters description: Parameters for a message signature - type: object properties: typedData: type: object properties: domain: type: object properties: name: type: string version: type: string chainId: type: number verifyingContract: type: string description: An EVM address string salt: type: string description: WebAuthn authenticator data as hex string required: - name - version - chainId - verifyingContract types: type: object additionalProperties: type: array items: type: object properties: name: type: string type: type: string required: - name - type primaryType: type: string message: type: object additionalProperties: true required: - domain - types - primaryType - message chain: type: string enum: - arbitrum-sepolia - arc-testnet - avalanche-fuji - curtis - base-goerli - base-sepolia - bsc-testnet - chiliz-spicy-testnet - coti-testnet - ethereum-goerli - ethereum-sepolia - hedera-testnet - hypersonic-testnet - lightlink-pegasus - mantle-sepolia - optimism-goerli - optimism-sepolia - polygon-amoy - polygon-mumbai - crossmint-private-testnet-ethereum - crossmint-private-testnet-polygon - rari-testnet - scroll-sepolia - sei-atlantic-2-testnet - shape-sepolia - skale-nebula-testnet - soneium-minato-testnet - space-testnet - story-testnet - verify-testnet - viction-testnet - xai-sepolia-testnet - zkatana - zkyoto - zora-goerli - zora-sepolia - mode-sepolia - u2u-nebulas - zenchain-testnet - abstract-testnet - world-chain-sepolia - plume-testnet - flow-testnet - tempo-testnet - ethereum - polygon - bsc - optimism - arbitrum - base - zora - arbitrumnova - astar-zkevm - apechain - hedera - coti - lightlink - mantle - skale-nebula - sei-pacific-1 - chiliz - avalanche - xai - shape - rari - scroll - viction - mode - space - soneium - story - u2u-solaris - abstract - world-chain - plume - flow - tempo description: The chain on which the signature will be submitted signer: description: The full signer object who will approve this signature oneOf: - type: object properties: type: type: string enum: - external-wallet address: type: string description: The address of the external wallet locator: type: string description: The locator of the external wallet signer required: - type - address - locator title: External Wallet Signer description: Full External Wallet signer object - type: object properties: type: type: string enum: - passkey id: type: string description: The ID of the passkey locator: type: string description: The locator of the passkey signer required: - type - id - locator title: Passkey Signer description: Full Passkey signer object - type: object properties: type: type: string enum: - api-key address: type: string description: The address of the api key locator: type: string description: The locator of the api key signer required: - type - address - locator title: API Key Signer description: Full API Key signer object - type: object properties: type: type: string enum: - device publicKey: type: object properties: x: type: string 'y': type: string required: - x - 'y' description: The p256 public key of the device signer locator: type: string description: The locator of the device signer name: description: Optional human-readable name for the device signer type: string required: - type - publicKey - locator title: Device Signer description: Full Device signer object - type: object properties: type: type: string enum: - email email: type: string format: email pattern: >- ^(?!\.)(?!.*\.\.)([A-Za-z0-9_'+\-\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\-]*\.)+[A-Za-z]{2,}$ locator: type: string required: - type - email - locator - type: object properties: type: type: string enum: - phone phone: type: string locator: type: string required: - type - phone - locator - type: object properties: type: type: string enum: - server address: type: string locator: type: string required: - type - address - locator isSmartWalletSignature: description: >- Whether the signature corresponds to the smart wallet or to the signer. If true, the signature will be wrapped with ERC6492. type: boolean required: - typedData - chain title: Typed data signature parameters description: Parameters for a typed data signature - type: object properties: authorizationEntries: type: string description: Base64-encoded XDR array of the authorization entries signer: description: The full signer object who will approve this entry oneOf: - type: object properties: type: type: string enum: - external-wallet address: type: string description: The address of the external wallet locator: type: string description: The locator of the external wallet signer required: - type - address - locator title: External Wallet Signer description: Full External Wallet signer object - type: object properties: type: type: string enum: - passkey id: type: string description: The ID of the passkey locator: type: string description: The locator of the passkey signer required: - type - id - locator title: Passkey Signer description: Full Passkey signer object - type: object properties: type: type: string enum: - api-key address: type: string description: The address of the api key locator: type: string description: The locator of the api key signer required: - type - address - locator title: API Key Signer description: Full API Key signer object - type: object properties: type: type: string enum: - device publicKey: type: object properties: x: type: string 'y': type: string required: - x - 'y' description: The p256 public key of the device signer locator: type: string description: The locator of the device signer name: description: Optional human-readable name for the device signer type: string required: - type - publicKey - locator title: Device Signer description: Full Device signer object - type: object properties: type: type: string enum: - email email: type: string format: email pattern: >- ^(?!\.)(?!.*\.\.)([A-Za-z0-9_'+\-\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\-]*\.)+[A-Za-z]{2,}$ locator: type: string required: - type - email - locator - type: object properties: type: type: string enum: - phone phone: type: string locator: type: string required: - type - phone - locator - type: object properties: type: type: string enum: - server address: type: string locator: type: string required: - type - address - locator required: - authorizationEntries title: Auth entries signature parameters description: Parameters for Stellar authorization entries signature (SEP-45) description: Type-specific signature parameters approvals: type: object properties: pending: type: array items: type: object properties: signer: oneOf: - type: object properties: type: type: string enum: - external-wallet address: type: string description: The address of the external wallet locator: type: string description: The locator of the external wallet signer required: - type - address - locator title: External Wallet Signer description: Full External Wallet signer object - type: object properties: type: type: string enum: - passkey id: type: string description: The ID of the passkey locator: type: string description: The locator of the passkey signer required: - type - id - locator title: Passkey Signer description: Full Passkey signer object - type: object properties: type: type: string enum: - api-key address: type: string description: The address of the api key locator: type: string description: The locator of the api key signer required: - type - address - locator title: API Key Signer description: Full API Key signer object - type: object properties: type: type: string enum: - device publicKey: type: object properties: x: type: string 'y': type: string required: - x - 'y' description: The p256 public key of the device signer locator: type: string description: The locator of the device signer name: description: Optional human-readable name for the device signer type: string required: - type - publicKey - locator title: Device Signer description: Full Device signer object - type: object properties: type: type: string enum: - email email: type: string format: email pattern: >- ^(?!\.)(?!.*\.\.)([A-Za-z0-9_'+\-\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\-]*\.)+[A-Za-z]{2,}$ locator: type: string required: - type - email - locator - type: object properties: type: type: string enum: - phone phone: type: string locator: type: string required: - type - phone - locator - type: object properties: type: type: string enum: - server address: type: string locator: type: string required: - type - address - locator description: The full signer object who submitted this signature message: type: string description: The message that needs to be signed required: - signer - message description: List of pending signatures submitted: type: array items: type: object properties: signature: type: string description: The cryptographic signature submittedAt: anyOf: - description: ISO 8601 formatted timestamp type: number - type: string description: ISO timestamp when the signature was created signer: oneOf: - type: object properties: type: type: string enum: - external-wallet address: type: string description: The address of the external wallet locator: type: string description: The locator of the external wallet signer required: - type - address - locator title: External Wallet Signer description: Full External Wallet signer object - type: object properties: type: type: string enum: - passkey id: type: string description: The ID of the passkey locator: type: string description: The locator of the passkey signer required: - type - id - locator title: Passkey Signer description: Full Passkey signer object - type: object properties: type: type: string enum: - api-key address: type: string description: The address of the api key locator: type: string description: The locator of the api key signer required: - type - address - locator title: API Key Signer description: Full API Key signer object - type: object properties: type: type: string enum: - device publicKey: type: object properties: x: type: string 'y': type: string required: - x - 'y' description: The p256 public key of the device signer locator: type: string description: The locator of the device signer name: description: Optional human-readable name for the device signer type: string required: - type - publicKey - locator title: Device Signer description: Full Device signer object - type: object properties: type: type: string enum: - email email: type: string format: email pattern: >- ^(?!\.)(?!.*\.\.)([A-Za-z0-9_'+\-\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\-]*\.)+[A-Za-z]{2,}$ locator: type: string required: - type - email - locator - type: object properties: type: type: string enum: - phone phone: type: string locator: type: string required: - type - phone - locator - type: object properties: type: type: string enum: - server address: type: string locator: type: string required: - type - address - locator description: The full signer object who submitted this signature message: type: string description: The message that was signed metadata: description: Additional metadata about the signature submission type: object properties: deviceInfo: type: string ipAddress: type: string userAgent: type: string required: - signature - submittedAt - signer - message description: Record of all submitted signatures required: description: Number of required approvals for the transaction type: number description: >- Complete approval data including requirements, pending and submitted signatures createdAt: anyOf: - description: ISO 8601 formatted timestamp type: number - type: string description: ISO timestamp when the signature was created completedAt: description: ISO timestamp when the transaction reached finality anyOf: - description: ISO 8601 formatted timestamp type: number - type: string error: description: Error message if the signature fails outputSignature: description: The wallet's output signature of the request type: string required: - id - type - chainType - walletType - status - params - approvals - createdAt WalletV1Alpha2ErrorDTO: type: object properties: error: type: boolean enum: - true message: type: string description: Error message example: required: - error - message ````