> ## 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. # Approve Signature > Submit approval for a signature to sign a message or typed data. **API scope required**: `wallets:signatures.create` ## OpenAPI ````yaml post /2025-06-09/wallets/{walletLocator}/signatures/{signatureId}/approvals 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/{signatureId}/approvals: post: summary: Approve Signature description: |- Submit approval for a signature to sign a message or typed data. **API scope required**: `wallets:signatures.create` operationId: WalletsV2025Controller-submitSignatureApprovals-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:` example: - '0x1234567890123456789012345678901234567890' - email:user@example.com:evm:smart - email:user@example.com:evm - email:user@example.com:evm:smart:alias:myWallet - userId:507f1f77bcf86cd799439011:solana:mpc - userId:did:example:cm4lr5piw0h6t1bjho0onryql:evm:smart - userId:507f1f77bcf86cd799439011:evm:alias:primary - phoneNumber:+12125551234:evm:smart - phoneNumber:+12125551234:evm:smart:alias:mobile - twitter:johndoe:evm:smart - x:@johndoe:evm:smart:alias:xWallet - me:evm:smart - me:evm:smart:alias:personal - evm:alias:myAlias schema: type: string - name: signatureId required: true in: path schema: type: string requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/SubmitApprovalV2025DTO' responses: '201': description: The signature has been successfully approved. content: application/json: schema: $ref: '#/components/schemas/WalletsSignatureV2025ResponseDTO' '400': description: Returns an error if the signature is not valid content: application/json: schema: $ref: '#/components/schemas/WalletV1Alpha2ErrorDTO' '404': description: Returns an error if the wallet or signature not found content: application/json: schema: $ref: '#/components/schemas/WalletV1Alpha2ErrorDTO' components: schemas: SubmitApprovalV2025DTO: type: object properties: approvals: type: array items: oneOf: - type: object properties: signer: type: string description: The locator for the passkey signer example: passkey:-y--aq1hqKC_ipuPHa-8aQ signature: type: object properties: r: type: string description: R component of the signature as a stringified bigint s: type: string description: S component of the signature as a stringified bigint required: - r - s description: The signature components metadata: type: object properties: authenticatorData: type: string description: WebAuthn authenticator data as hex string challengeIndex: type: number description: Index of the challenge used clientDataJSON: type: string description: WebAuthn client data JSON string typeIndex: type: number description: Index of the signature type userVerificationRequired: type: boolean description: Whether user verification was required required: - authenticatorData - challengeIndex - clientDataJSON - typeIndex - userVerificationRequired description: WebAuthn signature metadata required: - signer - signature - metadata description: Schema for WebAuthn signature data title: Passkey signature submission payload - type: object properties: signer: type: string description: The locator for the external wallet signer example: external-wallet:0x1234567890123456789012345678901234567890 signature: oneOf: - type: string - type: string description: The cryptographic signature example: 0x4551567890abcdef... required: - signer - signature title: External wallet signature submission payload description: Schema for external wallet signature submission - type: object properties: signer: type: string description: The locator for the email signer example: email:user@example.com signature: oneOf: - type: string - type: string description: The cryptographic signature example: 0x4551567890abcdef... required: - signer - signature title: Email signer signature submission payload description: Schema for email signer signature submission - type: object properties: signer: type: string description: The locator for the phone signer example: phone:+1234567890 signature: oneOf: - type: string - type: string description: The cryptographic signature example: 0x4551567890abcdef... required: - signer - signature title: Phone signer signature submission payload description: Schema for phone signer signature submission - type: object properties: signer: type: string description: The locator for the device signer example: device:BIVmCqMz8QJB+se2kJEpGQ... signature: type: object properties: r: type: string s: type: string required: - r - s description: The p256 signature with r and s components example: r: 0x1234... s: 0x5678... required: - signer - signature title: Device signer signature submission payload description: Schema for device signer signature submission minItems: 1 description: Array of approvals to submit for this transaction required: - approvals description: Input for submitting one or more approvals example: approvals: - signer: external-wallet:0x1234... signature: 0x1234567890abcdef... WalletsSignatureV2025ResponseDTO: type: object properties: id: type: string description: Unique identifier for the signature type: type: string enum: - message - typed-data 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: oneOf: - type: object properties: message: type: string description: The message in plain text to sign signer: discriminator: propertyName: type 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 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 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 description: >- The full signer object who will submit this signature. Defaults to the wallet's admin signer. 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 description: The chain on which the signature will be submitted required: - message description: Parameters for a message signature title: Message signature parameters - 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 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: {} 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 description: The chain on which the signature will be submitted signer: discriminator: propertyName: type 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 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 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 description: The full signer object who will approve this signature isSmartWalletSignature: type: boolean description: >- Whether the signature corresponds to the smart wallet or to the signer. If true, the signature will be wrapped with ERC6492. required: - typedData - chain description: Parameters for a typed data signature title: Typed data signature parameters description: Type-specific signature parameters approvals: type: object properties: pending: type: array items: type: object properties: signer: discriminator: propertyName: type 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 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 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 description: The full signer object that's pending approval 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: oneOf: - type: number description: ISO 8601 formatted timestamp example: '2024-01-01T00:00:00.000Z' - type: string description: When the signature was submitted example: '2024-01-01T00:00:00.000Z' signer: discriminator: propertyName: type 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 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 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 description: The full signer object who submitted this signature message: type: string description: The message that was signed metadata: type: object properties: deviceInfo: type: string ipAddress: type: string userAgent: type: string description: Additional metadata about the signature submission required: - signature - submittedAt - signer - message description: Record of all submitted signatures required: type: number description: Number of required approvals for the transaction required: - pending - submitted description: >- Complete approval data including requirements, pending and submitted signatures createdAt: oneOf: - type: number description: ISO 8601 formatted timestamp example: '2024-01-01T00:00:00.000Z' - type: string description: ISO timestamp when the signature was created example: '2024-01-01T00:00:00.000Z' completedAt: oneOf: - type: number description: ISO 8601 formatted timestamp example: '2024-01-01T00:00:00.000Z' - type: string description: ISO timestamp when the transaction reached finality example: '2024-01-01T00:00:00.000Z' error: description: Error message if the signature fails outputSignature: type: string description: The wallet's output signature of the request required: - id - type - chainType - walletType - status - params - createdAt description: >- Complete signature response including status, signing requirements, and wallet type specific data example: id: sig-b984491a-5785-43c0-8811-45d46fe6e520 type: message chainType: evm walletType: smart status: awaiting-approval params: message: Hello, world! signer: type: external-wallet address: '0xB17Ea8d34078424B9d7D126E444d5F2C3CC5c81E' locator: external-wallet:0xB17Ea8d34078424B9d7D126E444d5F2C3CC5c81E chain: polygon approvals: pending: - signer: type: external-wallet address: '0xB17Ea8d34078424B9d7D126E444d5F2C3CC5c81E' locator: external-wallet:0xB17Ea8d34078424B9d7D126E444d5F2C3CC5c81E message: Hello world! submitted: [] createdAt: '2024-01-01T00:00:00Z' WalletV1Alpha2ErrorDTO: type: object properties: error: type: boolean enum: - true message: type: string description: Error message example: required: - error - message description: Wallet error ````