worldchain tx lookup (0x..64hex): eth_getTransactionByHash + receipt; tx_not_found is a valid $0.01 verdict.

A2A/ACP/UCP/AP2/x402 discovery cross-check: fetch every well-known surface, extract the claimed endpoint URLs + capabilities, PROBE each claimed endpoint (payment endpoints must answer 402, not 200), and report per-surface claim-vs-runtime mismatches with a signed verdict. $0.01.

Wallet/URL drainer & abuse check via Chainabuse community reports: reported|no_reports + scam types. Signed.

Watch state: last verdict, uptime_30d and all-time ratios, consecutive fails, alert count.

Stateless WebAuthn/passkey verification: validate a registration (attestationObject + clientDataJSON) or assertion (authenticatorData + clientDataJSON + signature) against a caller-supplied challenge, origin and rpId — pure-python CBOR/COSE parsing, Ed25519 and ES256 signature checks, UP/UV flags, signCount, credential public key echo, per-check verdict.

Screen an ERC-8004 (Trustless Agents) agent identity: resolve tokenURI on the on-chain Identity Registry, fetch and parse the agentURI (ipfs/https/data:), live-probe its declared service endpoints (bounded), sample the reputation registry, and return a signed registered/reachable/grounded verdict. $0.01.

WebAuthn attestation trust check: parse attestationObject fmt/attStmt, verify packed and fido-u2f self-attestation signatures, verify x5c leaf certificate signatures when the crypto backend is present, echo AAGUID and credential material, and state the trust level (FIDO MDS not configured; never overstated).

DDG agent-payable service request

DDG agent-payable service request

Recompute an LLM bill line-by-line against OpenRouter published pricing and return a signed over/under/correct verdict.

DID/VC credential verification: resolve did:web/did:key (or an inline DID document), check the Ed25519 proof signature, verificationMethod/key-purpose match, validity window, revocation, and walk an AIP delegation chain (scope-subset + validity-nesting). Deterministic valid/invalid/unverifiable verdict with reason codes, Ed25519-signed. $0.01.

Rank potentially applicable EAR license-exception frames for an ECCN and destination.

Neutral escrow-condition oracle: from a deal + evidence emit a signed release|refund|extend|insufficient_evidence verdict. Never custodies funds.

Produce a pinnable MCP baseline snapshot: fetch the server's tool surface and emit per-tool fingerprints ({hash, description_sha, schema_sha, scopes}) plus a set-level snapshot_sha256. Signed. $0.01.

MCP tool-surface drift check: compare a pinned baseline (tool fingerprints) against the live surface (JSON-RPC tools/list, SSE-aware, well-known fallback) or an inline current_tools. Flags added/removed/renamed tools, description/schema changes, scope broadening, and injection-suspect text in new/changed descriptions. Signed verdict. $0.01.

Probe a live model endpoint once and get a signed latency/availability/consistency verdict vs the provider's claimed SLA.

Bulk x402 dup-guard: an array of up to 50 guard requests, each returning its derived key and allow/reject/replay-cache decision, with an aggregate summary.

Signed reserve digest for USDC, USDT, EURC and DAI: latest reserve figures, attestation timestamps and a per-issuer staleness verdict.

Buyer-side pre-spend gate: verdict under_cap/over_cap/unknown_coordinator against recorded ledger rows.

Deterministic claim-vs-source verification (CVE real? package vulnerable/exists? domain resolves? TLS cert valid? URL reachable?) against authoritative sources. Boolean verdict + evidence, no LLM.