Verifier Getting Started
Who Are Verifiers
Verifiers are the referees of deals — when transaction parties disagree on results, they provide objective, impartial rulings that take effect directly on-chain.
The form of the verifier doesn't matter; what matters is: the ruling must be correct, timely, and tamper-proof.
Verifier income comes from verification fees — automatically settled by the contract after each successful result submission.
Three Implementation Forms
| Form | Applicable Scenarios | Description |
|---|---|---|
| Pure code program | API-queryable, rule-based verification tasks | Preferred approach. Highest determinism, no subjective judgment bias. For example, calling the Twitter API to check if a tweet exists, querying on-chain state, etc. Low operating costs, fast response, fully reproducible results. |
| Human verifier | Tasks requiring offline verification or subjective judgment | Suitable for scenarios that pure code cannot cover — such as physical delivery confirmation, content quality assessment, etc. Human verifiers verify off-chain and manually submit results on-chain. |
| AI Agent | In between the two, requiring some reasoning ability | Can handle tasks more complex than pure code, but less stable than pure code. Watch out for hallucination, prompt injection, and other risks. |
Selection advice: Prefer pure code first. Use human verification for scenarios pure code cannot cover. AI Agents can be used but require thorough validation of stability and fairness.
Authority: What Makes People Trust You
No credentials, no platform endorsement. Authority comes entirely from on-chain historical records:
- Traders check your
success_count,fail_count, and timeout count before selecting you - Long-term high accuracy → higher search rankings → more quote requests
- One act of misconduct = reputation reset to zero; on-chain records are permanent
Authority is not granted — it is earned. Early participants who consistently respond correctly possess competitive advantages that latecomers cannot replicate.
Reliability: How to Ensure Response Dependability
Consequences of timeout without responding: verification fee refunded, timeout recorded on-chain, credit damage. Countermeasures:
- Monitoring & alerts — Off-chain services must have health checks configured to ensure timely notification on failure rather than silent failure
- Redundancy design — Critical dependencies should have backup plans, ensuring a definitive conclusion within the deadline
- Know your limits — If you cannot complete within the deadline, return
accepted: falseat therequest_signstage - Composite architecture — Multiple instances voting in parallel (majority rules) or sequential backup (switch on timeout), exposing only a single address externally
Code of Conduct
Verification parameters must be read from on-chain sources; never trust off-chain data. A signature is a commitment — once on-chain, it cannot be revoked. The verifier's duty is to report facts truthfully — make every effort to reach a definitive conclusion, and return 0 when unable to determine. Submitting conclusions without thorough verification constitutes a violation.