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Check Proof of Humanity

Proof of Humanity was originally created to verify community members taking part in the Linea Voyage. It aggregates many attestation providers, giving users many options (onchain transaction history, biometrics, zero-knowledge KYC, etc.) to demonstrate their personhood, using the Verax Attestation Registry under the hood.

Even though PoH was originally created for our own needs, the API is publicly available to the community. This enables projects to check and verify if an address is owned by a genuine user. It can be used to gate access to rewards or special services onchain (for example, to register a Linea Name).

To check and secure PoH status, visit the Linea PoH page.

Offchain verification​

The API endpoint for the service is: https://linea-xp-poh-api.linea.build/

Usage​

Call the endpoint with the format:

https://linea-xp-poh-api.linea.build/poh/{address}

For example:

curl -X GET "https://linea-xp-poh-api.linea.build/poh/0xc5fd29cC1a1b76ba52873fF943FEDFDD36cF46C6"

Response​

The main focus of the response is the poh field:

  • false = address does not have PoH status.
  • true = address has PoH status.

Response schema:

{
    "poh": boolean,  // Proof of Humanity status
    "isFlagged": boolean,  // Indicates PoH status
    "attestations": [
        {
        "validated": boolean,  // Whether the attestation is verified
        "issuerName": string,  // Attestation provider name
        "issuerSlugName": string,  // Unique identifier for the issuer
        "issuerDescription": string,  // Description of the attestation
        "issuerWebsiteUrl": string,  // URL to the issuer’s website
        "issuerLogoUrl": string,  // Logo URL of the issuer
        "group": integer  // Category of the attestation
        }
    ]
}

Reference​

See the Swagger UI for more information.

Signed onchain verification​

The PohVerifier.sol contract can be used together with a trusted source of PoH status data.

Usage​

Get signed PoH status​

Call the signer endpoint https://linea-poh-signer-api.linea.build/ in the format:

https://linea-poh-signer-api.linea.build/poh/{address}

This is the trusted source of PoH status data.

For example:

curl -X GET https://linea-poh-signer-api.linea.build/poh/0xc5fd29cC1a1b76ba52873fF943FEDFDD36cF46C6

This returns a signed message that contains the PoH status of the provided address. For example:

0xa11a6c92fa0027d9de2a0c8ab363b1af083497da57f871c93aeb9efcd32ffaeb677fafb2c005e8165181713220b8a1da2f70ed31d7820b8fa086a8e7361dbf121c

Call PohVerifier.sol​

Call the PohVerifier.sol smart contract's verify() function with the signed message and the address of the account being queried. The contract confirms that the signed message provided in the previous step was signed by the signer defined in the contract, and returns a boolean demonstrating whether the address has PoH status.

verify(bytes memory signature, address human)

Parameters:

  • signature: The signed message from the previous step.
  • address: The address of the account being queried.

verify() returns a boolean:

  • true: The account has PoH status.
  • false: The account does not have PoH status.