x402 Verification API
x402 verification APIs: proof, attestation, and validation endpoints that accept x402 payments per call. Agents can discover, price, and call these services per request, settling onchain through the HTTP 402 flow.
VERIFICATION SERVICES ── 51 total ── for live status visit /status
| NAME | DESCRIPTION | EP | FROM $/REQ | UPTIME 24H | NETWORKS |
|---|---|---|---|---|---|
| SYNTHORA AML Wallet Screen | Screens an EVM wallet address against OFAC SDN and EU consolidated sanctions lists, returning a sanctioned yes/no, the lists matched and a risk score. Responses carry an Ed25519 signed receipt. 0.005 USDC per call on Base, with a limited free trial per wallet. | 1 | $0.10 | 100.00% | BSE |
| SYNTHORA Wallet Reputation Score | Scores any EVM wallet address from 0 to 100 with a clean, suspicious or blacklisted tier, combining OFAC, Chainalysis oracle and TRM sanctions screening with GoPlus address-security flags and contract-vs-EOA detection. Responses are Ed25519-signed. 0.01 USDC per call on Base. | 1 | $0.32 | 100.00% | BSE |
| SYNTHORA Token Risk | Takes a token contract address on Base or Ethereum and returns a safe, caution, risky or rug_pull verdict, combining GoPlus token security data (honeypot simulation, buy and sell tax, holder count, ownership flags) with a bytecode scan, owner renounce check and honeypot.is. Ed25519 signed. | 1 | $0.32 | 100.00% | BSE |
| x402 Trust Prober | Deterministic trust scoring and monitoring for the x402 ecosystem. 88k+ endpoints tracked 24/7 on Base + Solana: probe reliability, latency, spec compliance, price history, and real on-chain USDC settlement per endpoint. Paid API: per-endpoint trust score with live re-probe, bulk scoring tiers (10-500), endpoint history, similar-endpoint discovery, payment tracing, and 30-day watch subscriptions with webhook/Slack alerts. Free: trust preview, leaderboard, ecosystem report, embeddable badges. Scoring is a deterministic formula - no LLM in the loop, fully explainable. | 10 | $0.005 | 100.00% | BSE |
| Second Opinion | Adversarial verification for AI agents: an independent skeptic attempts to refute a claim before the agent acts on it, returning a structured verdict (refuted / supported / inconclusive) with calibrated confidence, findings, and citations. Three tiers: quick reasoning check ($0.03) · single skeptic with live web research ($0.20) · three-skeptic panel with majority vote ($0.75). Every verdict carries an Ed25519-signed receipt verifiable offline against our published key. Accuracy benchmarked on the full public AVeriTeC dev set — 78.2% overall, 95.7% on refuted claims — with method and failures published at secondopinionx402.com/benchmark. Zero-install hosted MCP connector at /mcp; Python client: pip install secondopinion-x402. USDC via x402 on Algorand, Base, and Solana; no accounts, no API keys. | 6 | $0.03 | 100.00% | BSE/SOL |
| RattlerAI | Automated security audit for Solidity and EVM smart contracts, returning a Markdown report with findings by severity, proof of concept snippets and remediation notes. $2 USDC per call on Base or Solana. | 1 | $2.00 | 100.00% | BSE/SOL |
| verza | South African verification primitives for AI agents: identity and VAT number validation, and NCA credit-agreement lawfulness checks against the Regulation 42 interest caps. CIPC company lookup in development. Paid per call via the x402 protocol (USDC on Base). No accounts, no API keys. | 2 | $0.01 | 100.00% | BSE |
| FractalAI � Post-Quantum Proofs for AI Agents | Post-quantum (CRYSTALS-Dilithium-2, NIST FIPS 204) services for autonomous agents, payable per call in USDC on Base: Dilithium-2 signing, PQC signature verification, AI decision attestation (VAID-1), training-data attestation (C2PA), provenance sealing (drand + on-chain), CBOM cryptographic-inventory sealing, and Know-Your-Agent identity verification. Self-facilitated (EIP-3009 gasless) with a facilitator-less txHash fallback. Signatures are anchored on the FractalAI L1 with a public, verifiable attestation permalink. | 7 | $0.01 | 100.00% | BSE |
| Email Deliverability Audit (SPF, DKIM, DMARC) | Audits a domain's email deliverability from DNS only: SPF, DKIM selectors, DMARC policy strength, BIMI, MTA-STS and MX, returning a 0-100 score and prioritized fixes. Responses carry an Ed25519 signed receipt. 3 free calls per wallet via the X-WALLET header, then 0.001 USDC on Base. | 1 | $0.05 | 100.00% | BSE |
| SYNTHORA MTA-STS Audit | Audits a domain's SMTP transport security: resolves MTA-STS (RFC 8461) and TLS-RPT (RFC 8460) DNS records, fetches and parses the policy file, cross-checks policy mx patterns against the real MX, and returns a score, grade and enforce/report verdict. Responses carry an Ed25519 receipt. | 1 | $0.05 | 100.00% | BSE |
| Official Source Evidence | Pay-per-call exact OFAC identifier evidence and SEC filing-trigger deltas for autonomous agents, with official-source URLs, source hashes, freshness data, and signed receipts. | 2 | $0.05 | 100.00% | BSE |
| Datasource Pulse | One live health check on a data source, one instant machine-readable verdict. Monitor an Apify actor, API, or scraper for failures; check whether an API key silently failed; detect schema drift, stale data, empty results, dead credentials, rate limiting, and quota exhaustion. Validates keys for 35+ vendors (OpenAI, Anthropic, Stripe, GitHub and more), any HTTP endpoint, or a public Apify actor by id. Returns JSON: state, failure_class, message, recommended_action, latency_ms, metadata. | 1 | $0.02 | 100.00% | BSE |
| Vibes-Coded Agent Tool API | Pay-per-call reliability and intelligence APIs for AI agents on Solana USDC via x402: destructive-action, infra-target, tool-call-budget, agent-state, drift, retry-storm guards, action receipts, and 90+ more endpoints. HTTP 402, no signup. | 6 | $0.02 | 100.00% | BSE/SOL |
| Nishvault x402 Pre-Send Guard | 0.01 USDC on Base for pre-send EVM transaction simulation for AI agents. Returns an x402 v2 challenge and, after payment, a preflight result and proof receipt; never broadcasts the transaction. | 1 | $0.01 | 100.00% | BSE |
| token-risk | Static on-chain token/contract risk scanner (bytecode-only, safe): proxy/upgradeability, owner/mint/pause/blacklist/setFee selectors, Sourcify-verified source, honeypot heuristics. Deep tier adds contract-control analysis: owner()/admin readout, ownership-renounced?, EOA-vs-multisig owner, proxy implementation. USDC on Base via x402. | 2 | $0.02 | 100.00% | BSE |
| Watchtower | Deterministic sanctions screening for AI agents across OFAC/UN/EU/UK lists; x402 USDC on Base, no signup. | 1 | $0.02 | 100.00% | BSE |
| CottonmouthAI | POST /audit with Rust smart contract source or a GitHub URL and it returns an LLM generated security audit report, with per finding severity, description, proof of concept and fix. Covers CosmWasm, Anchor/Solana, Soroban and NEAR. $2 USDC per call on Base or Solana. | 1 | $2.00 | 100.00% | BSE/SOL |
| TrustFetch | Safety/content tools for AI agents: scan text for hidden prompt-injection attempts, or fetch+clean a webpage with built-in injection screening before your agent acts on it. | 5 | $0.015 | 100.00% | BSE/SOL |
| Hermes Plant | Deterministic pre-execution safety gates and signed evidence for AI agents. The Action Safety pair scores consequential shell, Git, SQL, infrastructure, and deployment commands, returning risk, matched rule IDs, and an exact machine-readable escalation call: $0.01 for the quick preflight, $0.25 for the full workflow with a signed receipt and free verification. High and critical outcomes are needs_review and are never represented as human-approved. Also includes wallet, MCP-server, and email risk scoring, x402 payment-policy decisions, demand-provenance checks, and deterministic finance math (DCF/IRR, Black-Scholes greeks, PE distribution waterfalls). Every route is on Base mainnet, settles through the CDP Facilitator, needs no account or API key, and is priced at or below $0.25. | 19 | $0.01 | 100.00% | BSE |
| IntentFence | Pre-transaction policy and quote safety checks for autonomous AI agents. Agents can pay per request in USDC on Base via x402 to receive bounded risk assessments and signed verification receipts. | 1 | $0.005 | 100.00% | BSE |
| LION — Verified Company & Compliance Data | AML wallet + company counterparty checks for AI agents. $0.001 wallet-screen (PASS/WARN/BLOCK OFAC check), $0.05 compliance bundle (OFAC + domain trust + firmographics), $0.012 deep research, $0.95 verified company file. Ed25519-attested JSON, keyless x402 on Base USDC. Buyer pack: https://lionx402.com/for-agents | 5 | $0.001 | 100.00% | BSE |
| Bounty Truth API | Deterministic preflight risk checks for public GitHub bounty issues. Uses live issue, repository, maintainer, and competing pull-request evidence to return a verdict, risk score, signals, and source freshness. x402 v2, $0.001 USDC on Base, no account or API key. | 1 | $0.001 | 100.00% | BSE |
| SYNTHORA Contract Watch | Monitors an EVM contract on Base or Ethereum and returns the current security verdict plus a diff of what changed since the last check: owner, proxy implementation, proxy admin, Sourcify verification, honeypot and tax flags. Ed25519-signed. 0.02 USDC per call on Base. | 1 | $0.32 | 100.00% | BSE |
| HexScan | Smart contract risk triage API. Send a contract address, get a composite risk score (0-100) with honeypot detection, tax analysis, source verification, and heuristic findings. Not an audit. | 1 | $0.10 | 100.00% | BSE |
| SYNTHORA MCP Server Security Scan | Scans an MCP server for security issues. Send a target URL or a pasted manifest; a deterministic rule engine checks embedded secrets, shell and filesystem capabilities, prompt injection surface and permissive input schemas, returning a security score, a risk tier and findings with remediation. | 1 | $0.05 | 100.00% | BSE |
| Canu Verify | Machine-first verification APIs for autonomous agents: deterministic MCP package security audits, isolated website and WebGL release QA, and structured invoice normalization or OCR verification with signed technical receipts. | 5 | $0.29 | 100.00% | BSE |
| SYNTHORA Bridge Risk Evaluator | Scores the risk of a cross-chain bridge before you route funds through it. Combines DefiLlama TVL, audit status and past bridge-hack incidents into a 0-100 score with a safe, caution, high risk or critical signal and the risk factors behind it. Responses carry an Ed25519 receipt. | 1 | $0.10 | 100.00% | BSE |
| SYNTHORA Mailcheck | Email address validation API. Returns RFC syntax check, live MX lookup, disposable and role account flags, free provider detection, gmail normalization, and a deliverability status with confidence score. No mail is sent. First 3 calls per wallet are free, then 0.001 USDC on Base. | 1 | $0.05 | 100.00% | BSE |
| Rubric Protocol — Post-Quantum AI Attestation | Post-quantum attestation and evidence services for AI agents. Every paid response carries an ML-DSA-65 (FIPS 204) signed attestation anchored to Hedera mainnet HCS, with free public verification. Catalog: pay-per-call decision attestation from $0.005, bulk hash anchoring from $0.000027/record, attested gpt-4o-mini inference binding prompt and response hashes to the exact model version, agent operating-history lookups computed from records that cannot be backdated, independent attestation audits with mirror-node confirmation, attested Hedera network facts from $0.001, and a regulatory-change feed for AI systems. A failed mint is never charged. | 10 | $0.001 | 100.00% | BSE |
| PulseFeed — x402 Trust & Safety Oracle | Verify any x402 endpoint before your agent pays: liveness, scam/anomaly scan (payTo hijack, bait-and-switch, honeypot), on-chain receiver verification and an open Trust Score. Continuous independent audit of the whole x402 ecosystem (~5k endpoints tracked). Paid: /trust $0.02, /trust/dataset $0.10, /data/full $1 (cross-domain x402+MCP dataset). Free: /verify, /status.json, /incidents (security disclosures with on-chain proof). | 3 | $0.02 | 100.00% | BSE |
| Aegis | Delivery-verified trust scoring for x402 services. Before your agent pays an unknown endpoint, Aegis returns a 0-100 trust score built from continuous live probes — liveness, well-formed 402 challenge, and price honesty against the advertised amount — plus real paid delivery spot-checks that confirm the service actually returns what it charged for. Registry of 2,393 scored services, published with a daily tamper-evident hash chain. Free capability discovery at /discover and /market, no wallet needed; /trust and /verify are $0.01 via x402 (USDC on Base). Also offers take-rate routing: pay Aegis once at /route and it buys the best-trusted upstream for you with per-item failover and auth-then-capture, so you are not charged if nothing delivers. | 4 | $0.01 | 100.00% | BSE |
| CopperheadAI | Security audit for Move smart contracts on Aptos and Sui. Post Move source or a GitHub URL and get back a structured report with findings graded by severity. | 1 | $2.00 | 100.00% | BSE/SOL |
| nsgoods Sanctions Screening Oracle | Multi-chain OFAC SDN exact-address screening. 960 sanctioned addresses across 19 chains, parsed directly from the US Treasury sdn_advanced.xml, including the Solana entries the Chainalysis on-chain oracle cannot see because it is EVM only. Every response is ECDSA-signed and carries sdn_snapshot_at, so a caller can prove which version of the list was used. The raw source file is hashed every six hours into a public append-only chain anchored to Bitcoin: https://sanctions.nsgoods.org/sdn-log/. Free preview on every endpoint, no account and no API key. Settles in USDC on Solana mainnet. | 1 | $0.005 | 100.00% | SOL |
| SYNTHORA Counterparty Risk Verdict | Composite counterparty risk check: given an EVM wallet and/or a token contract, returns a weighted 0-100 risk score, a proceed, pivot or kill verdict, and reason codes, fusing sanctions screening, wallet reputation and token contract heuristics. Deterministic, with an Ed25519 signed receipt. | 1 | $0.32 | 100.00% | BSE |
| StillOS Notary | Signed x402 verification and screening primitives: claim notarization, resolver-graded verdicts, OFAC SDN screening, and validated corporate distress scoring, backed by an on-chain correctness bond. | 2 | $0.10 | 100.00% | BSE |
| Herramientas Cobrables | Small deterministic pay-per-use services for AI agents: JSON contract validation, business margin and break-even calculations, and public stock quotes. Payments settle with x402 v2 using USDC on Base. | 3 | $0.01 | 100.00% | BSE |
| VirtualSMS | Pay-per-call SMS verification and OTP receiving for AI agents - real carrier numbers across 145+ countries and 2500+ services, from $0.05 per code in USDC via x402, no account or API key. For signup testing, account verification, and privacy. Also number rentals, matching-country proxies, and a hosted MCP server. | 1 | $0.10 | 100.00% | BSE/SOL |
| Dokimo Verify API | Pay-per-call x402 endpoint that independently recomputes a Merkle evidence proof to its committed root and returns a signed attestation. Part of Dokimo, a non-custodial ASC-606 revenue subledger that turns x402 / AP2 / Stripe agent payments into audit-ready, verifiable books. | 1 | $0.01 | 100.00% | BSE |
| Audit Tools | Evaluate an Apify actor before you use it. Send one actor ID (for example apify/instagram-scraper) and get an evidence-backed quality report: 23 built-in criteria like reliability, 30-day failure rate, advertised-field truth, and cost per usable item, deep-scan criteria measured from live funded runs, or your own rubric in plain English. Use it to audit a scraper, compare actor quality, or pick the best actor. Returns JSON with per-criterion scores, evidence, and a verdict. | 1 | $1.00 | 97.62% | BSE |
| LEI Lookup (GLEIF) | Looks up a Legal Entity Identifier against the public GLEIF registry and returns legal name, legal and headquarters address, registration status and registration dates. Three free calls per wallet via the X-WALLET header. | 1 | $0.002 | 0.00% | BSE |
| SYNTHORA BIC/SWIFT Check | Validates a BIC/SWIFT code (ISO 9362) from its structure: 8 or 11 character format, bank code, ISO 3166 country check, location and branch decode, live/test/passive flag. Structural check only, it does not query the SWIFT registry. First 3 calls free per wallet via the X-WALLET header. | 1 | $0.02 | 0.00% | BSE |
| Norravex x402 Endpoint Audit | Deterministic conformance and safety audit for public x402 HTTP 402 responses, with URL and payload modes, scored findings, and remediation. | 1 | $0.10 | 0.00% | BSE |
| German VAT Number Validator (SYNTHORA) | Validates German (DE) VAT numbers offline using the check-digit algorithm and returns a JSON verdict. Other EU country formats are declined by the endpoint. $0.001 USDC per call on Base, with 3 free calls per wallet. | 1 | $0.001 | 0.00% | BSE |
| SYNTHORA IBAN Check | Validates an IBAN offline: ISO 13616 mod-97 checksum, country and length registry check, BBAN and bank-code extraction, canonical formatting. Responses carry an Ed25519 signed receipt. First 3 calls per wallet are free via the X-WALLET header, then 0.001 USDC on Base. | 1 | $0.001 | 0.00% | BSE |
| SYNTHORA x402 Endpoint Preflight | Preflight check for x402 endpoints. Given an endpoint URL or a payTo address, it looks the resource up in the CDP Bazaar catalog, probes it for a live 402 challenge, compares declared against live payTo, and returns a 0-100 scorecard with a pay_ok, caution or do_not_pay verdict, signed with Ed25519. | 1 | $0.01 | 0.00% | BSE |
| SYNTHORA Address Risk Screen | Screens an EVM wallet address by proxying the free public GoPlus address_security API, returning a blacklist flag with an Ed25519 signed receipt. Free trial of 3 calls per wallet via an X-WALLET header. In testing, most detail fields came back empty. | 1 | $0.20 | 0.00% | BSE |
| SYNTHORA Agent Capability Attestation | Paid API that evaluates an AI agent's declared capabilities against supplied sample outputs using multiple LLMs, returning a 0-100 reliability score, a trust tier and a per-capability verdict in an Ed25519-signed response. | 1 | $0.10 | 0.00% | BSE |
| SYNTHORA Contract Guard | POST a Base contract address and receive a JSON safety verdict covering honeypot, rug pull, hidden mint and owner privileges, returned with an Ed25519 signature. One endpoint on the SYNTHORA agent services mesh operated by Hergert Synthora. | 1 | $0.005 | 0.00% | BSE |
| x402 FixSpec | Deterministic x402 endpoint conformance and remediation: unpaid challenge evidence, Base USDC requirement checks, discovery probes, prioritized fixes, and copy-ready OpenAPI, Bazaar, and agent-instruction templates. | 1 | $0.01 | 0.00% | BSE |
| SYNTHORA Agent Pre-Trade Safety | Returns a pre-trade risk verdict (SAFE, CAUTION or BLOCK) for an EVM address in one call, combining sanctions screening, stablecoin peg deviation in bps and a counterparty on-chain signal into an Ed25519-signed attestation. Scoring only, it never moves funds. | 1 | $0.20 | 0.00% | BSE |
| SYNTHORA Pre-Sign Transaction Verdict | Paid API returning an allow, warn or block verdict before a transaction is signed on Base or Ethereum. Takes transaction calldata or a token address, decodes unlimited approvals and screens the token and counterparty. 0.015 USDC per call. Risk data sources are operator declared. | 1 | $0.015 | 0.00% | BSE |
51 of 51 services ── category: Verification ── all services