Verifier Catalog

NEUS provides public verifiers available to all developers without API keys.

Each verifier is a standardized module that accepts specific input data, validates it, and produces a cryptographic proof.

Machine-readable source of truth:

• spec/VERIFIERS.json

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Ownership

Verifier	Flow	Expiry	Description
ownership-basic	Instant	Permanent	Content Authorship. Prove that a wallet created a specific piece of content. Includes origin locking.
ownership-pseudonym	Instant	Permanent	Handle Binding. Bind a wallet to a namespace + handle.
ownership-dns-txt	Lookup	Point-in-Time	Domain Control. Verify ownership of a DNS domain by checking a TXT record at _neus.{domain}.
contract-ownership	Lookup	Point-in-Time	Contract Control. Verify that a wallet is the contract owner, admin, or holds DEFAULT_ADMIN_ROLE (AccessControl), depending on method.

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Assets

Verifier	Flow	Expiry	Description
nft-ownership	Lookup	Point-in-Time	NFT Gating. Verify ownership of a specific ERC-721 or ERC-1155 token ID.
token-holding	Lookup	Point-in-Time	Token Gating. Verify that a wallet holds a minimum balance of a specific ERC-20 token.

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Identity & agents

Verifier	Flow	Expiry	Description
agent-identity	Instant	Permanent	Bot Identity. Establish a portable, self-attested identity for an AI agent, bot, or service (ERC-8004 compatible).
agent-delegation	Instant	Expiring	Authority Delegation. Cryptographically delegate authority (e.g., "can trade") from a controller to an agent.
wallet-link	Instant	Permanent	Account Linking. Link a secondary wallet to a primary identity using a cryptographic signature.
wallet-risk	Lookup	Point-in-Time	Sybil Resistance. Assess the risk level of a wallet address to prevent fraud and bot spam.

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Content safety

Verifier	Flow	Expiry	Description
ai-content-moderation	Lookup	Permanent	Safety Check. Analyze text or images for safety/moderation flags before allowing on-chain actions.

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Flow Types

• Instant: The verification is purely cryptographic or self-contained. It happens immediately upon receiving the signature.

• External lookup: The verification requires an external check (blockchain RPC, DNS query, AI provider).

Expiry Types

• Permanent: The proof remains valid indefinitely unless explicitly revoked by the user.

• Point-in-Time: The proof validates the state at that specific moment. For “must be true now” actions, create a fresh proof or require recency.

• Expiring: The proof contains an explicit expiration timestamp.

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Real-world usage (how to choose freshness)

Proofs are snapshots. For point-in-time verifiers (on-chain state, risk checks), you control freshness:

• Real-time / high-stakes actions (claims, mints, transfers): use strategy="fresh" (UI) or create a new proof (POST /api/v1/verification).

• Low-stakes UI gating: reuse proofs, but enforce a max age (recommended defaults below).

• Server-side eligibility checks: GET /api/v1/proofs/gate/check evaluates existing public/discoverable proofs; use since / sinceDays to require recent proofs.

Recommended max ages (defaults you can adopt):

• On-chain state (nft-ownership, token-holding, contract-ownership): 1 hour

• Off-chain control / provider-backed checks (ownership-dns-txt, wallet-risk): 1 hour

• Content moderation (ai-content-moderation): no recency window by default (content-hash bound). Re-run only if your policy/provider snapshot requirements change.

• Delegation (agent-delegation): enforce expiresAt (and treat expired as invalid)

Always avoid drift

To list what is enabled in a given deployment, call:

• GET /api/v1/verification/verifiers