--- title: "Create Signature" method: POST path: "/2025-06-09/wallets/{walletLocator}/signatures" --- # Create Signature `POST /2025-06-09/wallets/{walletLocator}/signatures` ## Request - Base URL: `https://staging.crossmint.com/api` - URL: `https://staging.crossmint.com/api/2025-06-09/wallets/{walletLocator}/signatures` - Auth: none required - TypeScript: (a function with typed inputs; its response is checked against the schema) Creates a new signature for signing messages or typed data. **API scope required**: `wallets:signatures.create` ## Path parameters - `walletLocator` string, required ## Headers - `X-API-KEY` string, required - `x-idempotency-key` string ## Request body - union: Input schema for creating a new signature. The parameters vary based on the signature type. - object: Parameters for a message signature - `type` 'message', required - `params` object, required: Parameters for a message signature - `message` string, required: The message in plain text to sign - `signer` string: The locator for the signer who will submit this signature. Defaults to the wallet's admin signer. - `chain` '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' | 'robinhood-chain-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' | 'robinhood-chain': The chain on which the signature will be submitted. Required for EVM wallets, optional for others. - object: Parameters for a typed data signature - `type` 'typed-data', required - `params` object, required: Parameters for a typed data signature - `typedData` object, required - `domain` object, required - `name` string, required - `version` string, required - `chainId` number, required - `verifyingContract` string, required: The recipient address for this transaction call - `salt` string: WebAuthn authenticator data as hex string - `types` object, required - `primaryType` string, required - `message` object, required - `chain` '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' | 'robinhood-chain-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' | 'robinhood-chain', required: The chain on which the signature will be submitted - `signer` string: The locator for the signer who will approve this signature - `isSmartWalletSignature` boolean: Whether the signature corresponds to the smart wallet or to the signer. If true, the signature will be wrapped with ERC6492. - object: Parameters for signing Stellar authorization entries (SEP-45) - `type` 'auth-entries', required - `params` object, required: Parameters for signing Stellar authorization entries (SEP-45) - `authorizationEntries` string, required: Base64-encoded XDR array of all authorization entries from the SEP-45 challenge (4-byte BE count prefix + concatenated entry XDR) - `signer` string: The locator for the signer who will approve this entry. Defaults to the wallet's admin signer. ## Response `201` The signature has been successfully created. - WalletsSignatureV2025ResponseDTO - `id` string, required: Unique identifier for the signature - `type` 'message' | 'typed-data' | 'auth-entries', required: The type of signature - `chainType` 'evm' | 'solana' | 'aptos' | 'sui' | 'stellar', required: The blockchain type of the wallet - `walletType` 'smart' | 'mpc', required: The wallet type (smart or mpc) - `status` 'awaiting-approval' | 'pending' | 'failed' | 'success', required: Current status of the signature - `params` union, required: Type-specific signature parameters - object: Parameters for a message signature - `message` string, required: The message in plain text to sign - `signer` union: The full signer object who will submit this signature. Defaults to the wallet's admin signer. - object: Full External Wallet signer object - `type` 'external-wallet', required - `address` string, required: The address of the external wallet - `locator` string, required: The locator of the external wallet signer - object: Full Passkey signer object - `type` 'passkey', required - `id` string, required: The ID of the passkey - `locator` string, required: The locator of the passkey signer - object: Full API Key signer object - `type` 'api-key', required - `address` string, required: The address of the api key - `locator` string, required: The locator of the api key signer - object: Full Device signer object - `type` 'device', required - `publicKey` object, required: The p256 public key of the device signer - `x` string, required - `y` string, required - `locator` string, required: The locator of the device signer - `name` string: Optional human-readable name for the device signer - object - `type` 'email', required - `email` string, email, required - `locator` string, required - object - `type` 'phone', required - `phone` string, required - `locator` string, required - object - `type` 'server', required - `address` string, required - `locator` string, required - `chain` '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' | 'robinhood-chain-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' | 'robinhood-chain': The chain on which the signature will be submitted - object: Parameters for a typed data signature - `typedData` object, required - `domain` object, required - `name` string, required - `version` string, required - `chainId` number, required - `verifyingContract` string, required: An EVM address string - `salt` string: WebAuthn authenticator data as hex string - `types` object, required - `primaryType` string, required - `message` object, required - `chain` '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' | 'robinhood-chain-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' | 'robinhood-chain', required: The chain on which the signature will be submitted - `signer` union: The full signer object who will approve this signature - object: Full External Wallet signer object - `type` 'external-wallet', required - `address` string, required: The address of the external wallet - `locator` string, required: The locator of the external wallet signer - object: Full Passkey signer object - `type` 'passkey', required - `id` string, required: The ID of the passkey - `locator` string, required: The locator of the passkey signer - object: Full API Key signer object - `type` 'api-key', required - `address` string, required: The address of the api key - `locator` string, required: The locator of the api key signer - object: Full Device signer object - `type` 'device', required - `publicKey` object, required: The p256 public key of the device signer - `x` string, required - `y` string, required - `locator` string, required: The locator of the device signer - `name` string: Optional human-readable name for the device signer - object - `type` 'email', required - `email` string, email, required - `locator` string, required - object - `type` 'phone', required - `phone` string, required - `locator` string, required - object - `type` 'server', required - `address` string, required - `locator` string, required - `isSmartWalletSignature` boolean: Whether the signature corresponds to the smart wallet or to the signer. If true, the signature will be wrapped with ERC6492. - object: Parameters for Stellar authorization entries signature (SEP-45) - `authorizationEntries` string, required: Base64-encoded XDR array of the authorization entries - `signer` union: The full signer object who will approve this entry - object: Full External Wallet signer object - `type` 'external-wallet', required - `address` string, required: The address of the external wallet - `locator` string, required: The locator of the external wallet signer - object: Full Passkey signer object - `type` 'passkey', required - `id` string, required: The ID of the passkey - `locator` string, required: The locator of the passkey signer - object: Full API Key signer object - `type` 'api-key', required - `address` string, required: The address of the api key - `locator` string, required: The locator of the api key signer - object: Full Device signer object - `type` 'device', required - `publicKey` object, required: The p256 public key of the device signer - `x` string, required - `y` string, required - `locator` string, required: The locator of the device signer - `name` string: Optional human-readable name for the device signer - object - `type` 'email', required - `email` string, email, required - `locator` string, required - object - `type` 'phone', required - `phone` string, required - `locator` string, required - object - `type` 'server', required - `address` string, required - `locator` string, required - `approvals` object, required: Complete approval data including requirements, pending and submitted signatures - `pending` union[]: List of pending signatures - union - object: Approval entry for a quorum (multisig) admin signer - `signer` object, required: The quorum signer this approval entry belongs to - `type` 'quorum', required - `locator` string, required: The derived `quorum:` locator of the quorum signer - `quorumApprovals` object, required: Per-member progress of an m-of-n quorum signer - `threshold` number, required: Number of member approvals required to satisfy the quorum - `remaining` number, required: Number of member approvals still outstanding to reach the threshold - `pending` object[], required: Quorum members that have not yet submitted - … - `submitted` object[], required: Quorum members that have already submitted - … - object - `signer` union, required: The full signer object who submitted this signature - object: Full External Wallet signer object - … - object: Full Passkey signer object - … - object: Full API Key signer object - … - object: Full Device signer object - … - object - … - object - … - object - … - `message` string, required: The message that needs to be signed - `submitted` union[]: Record of all submitted signatures - union - object: Approval entry for a quorum (multisig) admin signer - `signer` object, required: The quorum signer this approval entry belongs to - `type` 'quorum', required - `locator` string, required: The derived `quorum:` locator of the quorum signer - `quorumApprovals` object, required: Per-member progress of an m-of-n quorum signer - `threshold` number, required: Number of member approvals required to satisfy the quorum - `remaining` number, required: Number of member approvals still outstanding to reach the threshold - `pending` object[], required: Quorum members that have not yet submitted - … - `submitted` object[], required: Quorum members that have already submitted - … - object - `signature` string, required: The cryptographic signature - `submittedAt` union, required: ISO timestamp when the signature was created - number: ISO 8601 formatted timestamp - string - `signer` union, required: The full signer object who submitted this signature - object: Full External Wallet signer object - … - object: Full Passkey signer object - … - object: Full API Key signer object - … - object: Full Device signer object - … - object - … - object - … - object - … - `message` string, required: The message that was signed - `metadata` object: Additional metadata about the signature submission - `deviceInfo` string - `ipAddress` string - `userAgent` string - `required` number: Number of required approvals for the transaction - `createdAt` union, required: ISO timestamp when the signature was created - number: ISO 8601 formatted timestamp - string - `completedAt` union: ISO timestamp when the transaction reached finality - number: ISO 8601 formatted timestamp - string - `error` unknown - `outputSignature` string: The wallet's output signature of the request ## Other responses - `400`: Returns an error if the signature type is not supported - `404`: Returns an error if a wallet with the specified locator not found --- [API](https://skmtc.dev/crossmint/apis/onramp.md) - [All operations](https://skmtc.dev/crossmint/apis/onramp/llms.txt) - [OpenAPI document](https://skmtc.dev/crossmint/apis/onramp/revisions/e2143d192130?raw)