Signing Intents - NEAR Intents

After creating intents, they must be signed before submission to the Verifier contract via the execute_intents function. The Verifier supports multiple signature standards to enable signing from NEAR, Ethereum, TRON, Solana, Stellar, TON, and passkey-based wallets.

For intents structure before signing, see Intent Types and Execution.
For key management, see Account Abstraction.

Encoding Requirements for the Verifier Contract

Curve	Public Key	Signature
Ed25519	32 bytes	64 bytes
Secp256k1	64 bytes (uncompressed)	65 bytes (r \|\| s \|\| v)
P256	64 bytes (uncompressed)	64 bytes (r \|\| s)

Important: Compressed public keys are not supported for ECDSA curves (Secp256k1, P256). Public keys must be in uncompressed format (raw 64-byte x || y coordinates without prefix bytes).Signatures must be in raw concatenated byte format, not DER-encoded.

Every public key registered to an account can sign intents on its behalf. See Account Abstraction for key management details.

Signature types

Different wallets use different signing standards. To allow users to sign with their existing wallet, the Verifier supports multiple verification methods — each corresponding to a specific wallet ecosystem (e.g., ERC-191 for MetaMask, Raw Ed25519 for Phantom). Each signed intent conforms to the MultiPayload enum.

NEP-413

The NEP-413 standard is an off-chain message signing standard recognized by NEAR wallets.

Field	Description
`standard`	`"nep413"`.
`payload.recipient`	Contract address (e.g., `intents.near`). Prevents replay on other contracts.
`payload.nonce`	Base64-encoded 256-bit nonce.
`payload.message`	Serialized JSON payload string containing `signer_id`, `deadline`, and `intents`.
`public_key`	Signer’s public key. Encoded as key type prefix + base58 (e.g., `ed25519:...`).
`signature`	Cryptographic signature. Encoded as key type prefix + base58.

{
  "standard": "nep413",
  "payload": {
    "recipient": "intents.near",
    "nonce": "Vij2xgAlKBKzgNPJFViEQRgYyS7p2NEiYTTY4XmT8go=",
    "message": "{\"deadline\":\"2025-05-21T10:34:04.254392Z\",\"intents\":[{\"intent\":\"transfer\",\"receiver_id\":\"bob.near\",\"tokens\":{\"nep141:usdc.near\":\"10\"}}],\"signer_id\":\"alice.near\"}"
  },
  "public_key": "ed25519:C3jXhkGhEx88Gj7XKtUziJKXEBMRaJ67bWFkxJikVxZ2",
  "signature": "ed25519:2ns3eCikZFxFA6e9ApunuDG4XwJUPrB8q82fYViBKjheqiDYcCmLN9RnB9NhoEvCdNoS3L3qYD9FAnKd7UkTnuij"
}

ERC-191

Compliant with the ERC-191 standard for off-chain message signing (Ethereum wallets like MetaMask).

Field	Description
`standard`	`"erc191"`.
`payload`	Serialized JSON payload string. The `signer_id` is the Ethereum address.
`signature`	Secp256k1 signature. Encoded as key type prefix + base58 (e.g., `secp256k1:...`).

There is no public_key field because it can be recovered from the secp256k1 signature and data.

Ethereum clients shift the recovery byte (v) based on chain ID. The Verifier contract expects v ∈ {0, 1}, so clients must normalize the recovery byte before submission.

{
  "standard": "erc191",
  "payload": "{\"signer_id\":\"0xca67C1Bb3FD69857E5edaF6aA1c65371bF46A464\",\"verifying_contract\":\"intents.near\",\"deadline\":\"2025-05-26T13:24:16.983Z\",\"nonce\":\"Vij2xgAlKBKzwGNqwogWQxiy87p9jW5Omfg+L9bXBDw=\",\"intents\":[{\"intent\":\"token_diff\",\"diff\":{\"nep141:usdc.near\":\"-1000\",\"nep141:usdt.near\":\"1000\"}},{\"intent\":\"ft_withdraw\",\"token\":\"usdt.near\",\"receiver_id\":\"bob.near\",\"amount\":\"1000\"}]}",
  "signature": "secp256k1:BoR53NKKJ2GfP8bETk427Xav8VMpUcZovLzXeq2EsUD7NnPH2sSmxWFEkDUrguJHHkiu3GwEQxxMo2Rm2ZTDHFygU"
}

TIP-191

Compliant with TIP-191, TRON’s off-chain message signing standard. TIP-191 is fully compatible with ERC-191.

Field	Description
`standard`	`"tip191"`.
`payload`	Serialized JSON payload string. The `signer_id` is the TRON address.
`signature`	Secp256k1 signature. Encoded as key type prefix + base58 (e.g., `secp256k1:...`).

Like ERC-191, there is no public_key field because it can be recovered from the secp256k1 signature and data. The same recovery byte normalization applies.

Raw Ed25519

Used by Phantom wallet for Solana off-chain message signing.

Field	Description
`standard`	`"raw_ed25519"`.
`payload`	Serialized JSON payload string. Note: `deadline` uses a Unix `timestamp` instead of ISO 8601.
`public_key`	Signer’s public key. Encoded as key type prefix + base58.
`signature`	Ed25519 signature. Encoded as key type prefix + base58.

{
  "standard": "raw_ed25519",
  "payload": "{\"signer_id\":\"alice.near\",\"verifying_contract\":\"intents.near\",\"deadline\":{\"timestamp\":1732035219},\"nonce\":\"Vij2xgAlKBKzwGNqwogWQxi9ZuGDNBXlmdy9g3MQSMk=\",\"intents\":[{\"intent\":\"token_diff\",\"diff\":{\"nep141:usdc.near\":\"-1000\",\"nep141:usdt.near\":\"998\"}}]}",
  "public_key": "ed25519:9aqyNsCRrDkq9SceVRCdW1Zs9BmEP8ieJQRJim8iRLF",
  "signature": "ed25519:9RHRenkbYN6cfWXkou47sjAf1PuTc6nYM8amHADApfqio8dcMQu28cgfz6wkktBFoE8J7FsZ3rxifFdMdzTTJi6"
}

WebAuthn (Passkey)

For use with passkeys and the Web Authentication standard. The signature can use either Ed25519 or P256 (secp256r1).

Field	Description
`standard`	`"webauthn"`.
`payload`	Serialized JSON payload string.
`public_key`	Signer’s public key. Encoded as key type prefix (`p256` or `ed25519`) + base58.
`signature`	Cryptographic signature. Encoded as key type prefix (`p256` or `ed25519`) + base58.
`client_data_json`	WebAuthn client data JSON. Contains `type`, `challenge` (base64 URL-safe), and `origin`.
`authenticator_data`	Authenticator assertion data. Encoded as base64, URL-safe.

{
  "standard": "webauthn",
  "payload": "{\"signer_id\":\"0x3602b546589a8fcafdce7fad64a46f91db0e4d50\",\"verifying_contract\":\"intents.near\",\"deadline\":\"2025-03-30T00:00:00Z\",\"nonce\":\"A3nsY1GMVjzyXL3mUzOOP3KT+5a0Ruy+QDNWPhchnxM=\",\"intents\":[{\"intent\":\"transfer\",\"receiver_id\":\"bob.near\",\"tokens\":{\"nep141:usdc.near\":\"1000\"}}]}",
  "public_key": "p256:2V8Np9vGqLiwVZ8qmMmpkxU7CTRqje4WtwFeLimSwuuyF1rddQK5fELiMgxUnYbVjbZHCNnGc6fAe4JeDcVxgj3Q",
  "signature": "p256:3KBMZ72BHUiVfE1ey5dpi3KgbXvSEf9kuxgBEax7qLBQtidZExxxjjQk1hTTGFRrPvUoEStfrjoFNVVW4Abar94W",
  "client_data_json": "{\"type\":\"webauthn.get\",\"challenge\":\"4cveZsIe6p-WaEcL-Lhtzt3SZuXbYsjDdlFhLNrSjjk\",\"origin\":\"https://defuse-widget-git-feat-passkeys-defuse-94bbc1b2.vercel.app\"}",
  "authenticator_data": "933cQogpBzE3RSAYSAkfWoNEcBd3X84PxE8iRrRVxMgdAAAAAA=="
}

TonConnect

Follows the standard for data signing on TON.

Field	Description
`address`	TON wallet address.
`domain`	Domain associated with the signing request.
`timestamp`	ISO 8601 timestamp of the signing request.
`payload.type`	`"text"`.
`payload.text`	Serialized JSON payload string containing `signer_id`, `deadline`, and `intents`.
`public_key`	Signer’s public key. Encoded as key type prefix + base58.
`signature`	Ed25519 signature. Encoded as key type prefix + base58.

{
  "address": "EXvSRnDlYHziOJRm1MqGLgQB3EN7319eZLYWVinpoPv7LkBd",
  "domain": "example.com",
  "timestamp": "2025-01-01T00:00:00Z",
  "payload": {
    "type": "text",
    "text": "{\"signer_id\":\"alice.near\",\"verifying_contract\":\"intent.near\",\"deadline\":\"2025-05-26T15:19:43.617898Z\",\"nonce\":\"ZnbiFf4tP4cn65XLuZ6T1H6/Vr3o6ucNftdx3pInLnc=\",\"intents\":[{\"intent\":\"ft_withdraw\",\"token\":\"usdc.near\",\"receiver_id\":\"bob.near\",\"amount\":\"1000\"}]}"
  },
  "public_key": "ed25519:G4HVCaJg9vZb2srcLoWxR9grQ3tGLNFMVrZBhTtBi4Q1",
  "signature": "ed25519:5cwYdTNeGy1mApo9RNor9hSXvcG6GbvVm6di6kuf4frnARtVWRpJoPtvFKHMbt7uDGDtgFfn6bPDFGPK5jamqBwC"
}

SEP-53

Compliant with SEP-53, Stellar’s standard for signing arbitrary messages using Stellar key pairs.

Field	Description
`standard`	`"sep53"`.
`payload`	Serialized JSON payload string.
`public_key`	Signer’s public key. Encoded as key type prefix + base58 (e.g., `ed25519:...`).
`signature`	Ed25519 signature. Encoded as key type prefix + base58.

Adding more signature types

To support additional key or signature types, contact the NEAR Intents team via Telegram.

​Signature types

​NEP-413

​ERC-191

​TIP-191

​Raw Ed25519

​WebAuthn (Passkey)

​TonConnect

​SEP-53

​Adding more signature types

Signature types

NEP-413

ERC-191

TIP-191

Raw Ed25519

WebAuthn (Passkey)

TonConnect

SEP-53

Adding more signature types