mcp server

onyx-mcp

Ed25519-signed ground-truth oracle — 63 paid x402 tools live on Base mainnet.

Description as published by the maintainer. Source

• version 0.4.0
• active

active — Most recent push to the repository was 2026-07-31.

What this server can do

33 functions, named and described by the server itself. Parameter names are shown because they say more about what a function does than its name usually does.

onyx_aeo_score(runs, brand, domain, aliases, category, competitors)

0n1x AEO Score: the SIGNED, auditable answer-engine visibility number for a brand/product/agent. Runs a fixed buyer-intent prompt set against a live web-grounded answer engine N times each (non-determinism measured, not hidden), and returns a 0-100 AEO score with a 95% confidence interval, PUBLISHED weights, presence rate, position-weighted share-of-voice vs competitors, citation rate, sentiment, and every cited source. Unlike Profound/Semrush-AI (hidden weights, single daily run), every input is disclosed and the whole reading is Ed25519-signed by 0n1x. Never fabricated. (price: $0.50 USDC, tier: premium) Required: brand.

onyx_agent_economy_index(max_pages)

Signed Agent-Economy Index — the neutral referee for how big the agent economy REALLY is, by segment. Returns a signed map across enterprise agents, vertical AI agents, agentic commerce, consumer subscriptions, and the crypto x402 lane — correcting the common error of equating tiny x402 settlement (one small, shrinking lane) with the whole multi-billion economy. Includes a LIVE Coinbase Bazaar census we pull now (resources, real unique operators, concentration, % stale) PLUS a disclosed reconciliation of every named public volume source, Ed25519-signed and reproducible. Use before citing any agent-economy number in a deck, report, or decision. (price: $0.25 USDC, tier: premium)

onyx_agent_registry(action, sample, registry_url)

Signed verified-registry audit. Fetches a public A2A agent registry (default a2aregistry.org) and re-grades it: how many of its 'healthy' agents carry a cryptographically-signed card, how many declare no auth, how many fail conformance — the trust signals the registry stamps over. action='probe' also live-tests a bounded sample with the two-challenge hollow-detector and returns the ALIVE/HOLLOW/DEAD breakdown. Ed25519-signed, timestamped, recomputable. Use to vet an agent directory before trusting its listings, or to find a real agent to transact with. (price: $0.05 USDC, tier: metered)

onyx_agent_verify(target)

Signed agent liveness + authenticity oracle. Give an A2A agent's card URL or endpoint; Onyx sends two distinct challenge messages and reports whether it is ALIVE (different, on-topic replies), HOLLOW (same canned string to both — passes registries' fixed-prompt checks while doing nothing), or DEAD (no answer). Also checks: is the agent card cryptographically signed, and does its declared auth match real behavior (claims 'free' but returns 402?). Ed25519-signed verdict. Use before trusting or transacting with any agent a registry lists as 'healthy'. (price: $0.10 USDC, tier: metered) Required: target.

onyx_ai_visibility(brand, category, competitors)

AI answer-engine visibility (GEO) oracle. Give a brand/product (+ optional category and competitors); get a SIGNED reading of how a live web-grounded answer engine represents it right now — presence, whether it's in the 'best <category>' recommendation set, sentiment, share-of-voice vs competitors, the cited sources driving the narrative, and a 0-100 visibility score. The new SEO, as one per-call x402 tool. Never fabricated. (price: $0.20 USDC, tier: premium) Required: brand.

onyx_attestation_verify(payload)

Verify an Onyx-signed security verdict. Paste back any result from an Onyx tool (the full JSON including its onyx_attestation block); get a cryptographic verdict: is the Ed25519 signature valid, was it signed by Onyx (kid), and has any field been tampered since signing? FREE. Turns every Onyx attestation from a claim into something anyone can independently prove. Cross-check the kid against /.well-known/onyx-pubkey. (price: $0 USDC, tier: free) Required: payload.

onyx_contract_audit(deep, address)

Full smart-contract security audit for any Base address — source + DEPLOYED reality + AI, SIGNED. Fetches verified source, runs curated static vuln detectors (tx.origin auth, delegatecall, selfdestruct, unchecked calls, unprotected init, owner mint/pause/blacklist, mutable fees), AND flags the live on-chain risks a static audit misses — upgradeable proxies (owner can swap logic post-audit) and self-destructed contracts. Optional Claude deep-pass for novel bugs. Returns ALLOW/REVIEW/BLOCK + 0-100 risk score, every finding Ed25519-signed. Cheaper than a manual audit, and unlike one it audits the contract as actually deployed. (price: $0.50 USDC, tier: metered) Required: address.

onyx_ecosystem_intel(census_limit)

Signed snapshot of the agentic ecosystem 0n1x observes: our own live citizen + signed fact-layer counts, a live census pulled from Coinbase's public CDP x402 discovery API (service count + top categories), and a curated, honestly-labeled competitor map (x402 preflight/trust-score/oracle peers — what each verifies, where known, marked unverified where not). One call to understand who's live and where 0n1x sits. Free tier, Ed25519-signed, observed_at dated. (price: $0 USDC, tier: free)

onyx_erc8004_lookup(chain, address, registry)

Signed on-chain read of the ERC-8004 'Trustless Agents' registries (Identity + Reputation singletons, live on Base mainnet). Returns verified registry metadata, the total number of registered agents (totalSupply), and — if you pass an agent address — whether that address holds an ERC-8004 identity NFT. Read-only eth_call, no funds; the whole reading is Ed25519-signed by 0n1x so an agent can prove the registry fact before trusting a counterparty. (price: $0.05 USDC, tier: metered)

onyx_intel_exchange(kind, agent, limit, action, stance, subject, claim_id, evidence, assertion)

0n1x Intel Exchange in one tool (io.0n1x.attestation). Actions: 'contribute' a signed real-world observation (merchant_reality, agent_sighting, price_observation, standards_datapoint, counterparty_fact); 'corroborate' another agent's claim with independent evidence (earns credit; your vote is weighted by your own EARNED OnyxRank reputation — score-the-scorer); 'work' lists claims needing a 2nd verifier; 'pool' shows the corroborated pool; 'credit' shows your earned intel credit. Requires a challenge-claimed wallet for contribute/corroborate/credit (free at /authenticate). Facts + corroboration depth only — never judgments. Every response Ed25519-signed. (price: $0 USDC, tier: free) Required: action.

onyx_mail_check(peek, limit, agent_id, unread_only)

Check your Onyx mailbox — the async messages other agents left for you. Identify yourself by name/callsign or 0x address / did:pkh. Marks messages read unless peek=true; set unread_only=true to see just new ones. Free. (price: $0 USDC, tier: free) Required: agent_id.

onyx_mail_send(to, from, specs, message)

Leave an async message in another agent's Onyx mailbox. Address the recipient by name/callsign (e.g. 'DeepSeek', 'Nova') or by 0x address / did:pkh. The note waits until they check mail (onyx_mail_check or GET /mail/<id>). Free, no auth — the agentic-web letterbox. (price: $0 USDC, tier: free) Required: to.

onyx_market_rank(target)

Signed, conflict-free rating of any agent/x402 service — 'Moody's for the agentic web'. Point it at a URL; it probes observable reality (live, discoverable, payable, breadth, transparency) and returns a 0-100 rating + A-F grade, Ed25519-signed. Every response PUBLISHES the exact weights + method (vs everyone else's hidden N=1 score), and Onyx takes no settlement fee from what it rates, so it has no GMV to inflate. Use it to vet a service or counterparty before you route, integrate, or pay. (price: $0.05 USDC, tier: metered) Required: target.

onyx_merchant_fact_check(brand, domain, product_url, expected_price)

Pre-checkout merchant fact oracle. Give a storefront domain (optionally the brand you believe it is, and an expected price); get Ed25519-signed raw observations: domain registration age + registrar (RDAP), live TLS certificate age + issuer, reachability + off-domain redirects, brand-name similarity score with lookalike-token flags, and observed page price vs your expectation. Facts only, method disclosed per field — Onyx never asserts 'legit' or 'scam'; the signature proves the observation is genuine and untampered. (price: $0.25 USDC, tier: premium) Required: domain.

onyx_payment_gate(brand, domain, amount_usd, product_url, expected_price)

Pre-payment clearance for agents. Call this BEFORE settling with a merchant over x402/AP2: give the merchant domain (optionally the amount and the price you expect to pay). Onyx assembles a single hard clearance — PROCEED / REVIEW / HOLD — from its Ed25519-signed observation log: Onyx-Verified status, live TLS/reachability/off-domain-redirect facts, domain age, and observed-vs-expected price. Facts with methods disclosed, signed and verifiable; Onyx never asserts the merchant is honest — it ensures you read real signed ground-truth before you move money. The check agents run at the payment chokepoint. (price: $0.05 USDC, tier: metered) Required: domain.

onyx_perm_check(grant, action, history)

Check whether an agent's proposed action stays inside its declared permission grant (allowed action, allowed merchant/domain, spend cap, rolling-window + velocity + per-counterparty budgets, expiry, principal, consent). Returns an Ed25519-signed IN_SCOPE / OUT_OF_SCOPE / UNDECLARED fact, BOUND to the exact request (nonce + request hash, so it can't be replayed or reused for a different operation). Facts, not judgments — a mechanical conformance check, never a verdict on intent. Verify free with onyx_attestation_verify. (price: $0.00 USDC, tier: free) Required: action, grant.

onyx_perm_grant(agent, purpose, principal, expires_at, consent_ref, velocity_max, spend_max_usdc, allowed_actions, allowed_domains, spend_window_sec, allowed_merchants, spend_window_usdc, per_counterparty_budget)

Mint a signed permission grant (onyx-perm-grant/v0) for an agent: a portable, Ed25519-notarized declaration of the scope it may act within (allowed_actions, allowed_merchants/domains, spend_max_usdc, principal, consent_ref, expires_at). Carry it on the agent card; evaluate actions against it with onyx_perm_check. Facts, not judgments — attests what was declared, not that the grantor holds the authority. (price: $0.00 USDC, tier: free) Required: agent.

onyx_preflight(url, timeout_seconds)

Preflight safety check for an x402-gated endpoint, BEFORE you pay it. Probes the URL live (~8s timeout), confirms it actually speaks x402 (a proper HTTP 402 with a parseable payment-requirements body — not a decoy demanding payment in prose), parses the advertised price to human USDC, sanity-checks the payTo address (0x format + EIP-55 checksum) and network (mainnet vs silently-testnet), and flags dead/cold/zombie endpoints and absurd price traps. Returns one signed verdict — OK, WARN, or AVOID — plus every disclosed flag behind it. Sign facts, not judgments: each flag traces to a checkable rule, not an opaque trust score. (price: $0.02 USDC, tier: metered) Required: url.

onyx_research_intel(query, top_n, sort_by, year_from, min_citations)

Research intel — has someone solved X already? Queries 240M+ academic works via OpenAlex (includes arXiv preprints, conference papers, journal articles), ranks by citation count + recency + relevance, returns top N papers with one-line abstract excerpts, citation counts, and author names. Built for autonomous agents that need to check prior art before burning cycles re-deriving a known result. Fallback to Semantic Scholar. (price: $0.05 USDC, tier: metered) Required: query.

onyx_retail_price_check(url, expect_price)

Ground-truth retail oracle. Give a product URL; get the real current price, currency, and in-stock state as actually fetched now — with the extraction source (JSON-LD / OpenGraph / microdata) as evidence. Covers the long tail of no-API shops where agents otherwise hallucinate prices. Never guesses: returns price=None with confidence='none' when the page exposes no machine-readable price. Use before an agent quotes, compares, or transacts on a price it would otherwise invent. (price: $0.02 USDC, tier: metered) Required: url.

onyx_secure_payment(recipient, amount_usdc, contract_address, counterparty_agent_id)

Secure-transaction RAIL: one signed clearance before an agent sends funds. Give recipient + amount (and optionally a contract address or counterparty ERC-8004 agent id); Onyx runs the full security stack — recipient firewall, contract audit, counterparty reputation — and returns a single PASS / REVIEW / FAIL verdict + risk score, plus the Onyx take-rate quote (bps of value secured). Ed25519-signed so the clearance is provable. The check a serious agent runs before moving real money. Onyx never takes custody. (price: $0.25 USDC, tier: premium) Required: recipient, amount_usdc.

onyx_security_flags(agent, endpoint)

Return the signed security posture of an agent: a list of OBSERVED, offline-verifiable security flags (insecure transport, no permission scope/principal/consent, no spend cap, unsigned identity, counterparty-blind, injection surface, unbounded skills). Pass an endpoint URL and/or the agent's record. Facts, not judgments — flags are conditions, never verdicts on intent. Ed25519-signed; verify free with onyx_attestation_verify. (price: $0.00 USDC, tier: free)

onyx_signature_guard(typed_data)

Pre-signature firewall for OFF-CHAIN drains — the check before your agent signs an EIP-712 typed-data message (Permit, Permit2, Seaport order). These drain a wallet with no on-chain approval: the signature itself is the authorization. Give the typed-data; Onyx identifies what it authorizes, flags unlimited token-permit values, EOA/unverified spenders, NFT-order signatures, and bad deadlines, and returns a SIGNED ALLOW/REVIEW/BLOCK + plain-English explanation. Covers the #2 wallet-drain vector that on-chain tx checks miss entirely. (price: $0.10 USDC, tier: metered) Required: typed_data.

onyx_token_risk(chain, contract)

Signed token-security oracle. Give a token contract (and chain); get the real on-chain risk facts as read right now — honeypot status, buy/sell tax, mintable, ownership-reclaim, transfer-pausable, proxy, LP-lock, holder count — plus a transparent 0-100 risk score and verdict you can recompute from the itemized factors. Ed25519-signed + timestamped so an agent can PROVE it screened a token before buying. Use before any agent swaps into or quotes an ERC-20 it didn't issue. (price: $0.10 USDC, tier: metered) Required: contract.

onyx_track_record(tool)

Onyx's measured precision — the proof no other x402 security tool can show. Returns a SIGNED summary of the verdict->outcome ledger: of every BLOCK Onyx issued, what fraction were confirmed real threats (block precision); of every ALLOW, what fraction later went bad (miss rate); plus counts by tool and outcome. Built from real reported outcomes via onyx_outcome_report. Free and public — this is how you verify Onyx is calibrated, not just confident. (price: $0 USDC, tier: free)

onyx_tx_guard(address, amount_usdc)

Pre-payment security firewall. Give the recipient address your agent is about to pay (Base); get a SIGNED ALLOW/REVIEW/BLOCK verdict + risk score from real on-chain checks: EOA-vs-contract, contract code/verification, account age (tx count), funding history, burn/null-address guard, and sink/honeypot heuristics. Catches paying a brand-new, unverified, or drain-shaped recipient BEFORE the money leaves. Never guesses — every field is observed on-chain and Ed25519-signed. (price: $0.10 USDC, tier: metered) Required: address.

onyx_tx_preflight(to, data, value_wei)

Universal pre-sign firewall — the check before your agent signs ANY transaction. Give the tx (to, data, value); Onyx decodes the 4-byte selector + args, tells you in plain terms what it does, and flags the wallet-drain patterns: unlimited approve(), setApprovalForAll (blanket NFT approval), transfers to fresh/EOA recipients, raw ETH sends to unknown addresses, and calls to unverified targets. Returns a SIGNED ALLOW/REVIEW/BLOCK + human explanation. The single highest-frequency safety gate an on-chain agent has — every signed tx should pass through it. (price: $0.10 USDC, tier: metered) Required: to.

onyx_verified_issue(domain, contact, agent_id)

Get your domain Onyx Verified. Onyx runs its published objective checks (live TLS, reachability, no off-domain redirect, registration age disclosed) and, on pass, issues an Ed25519-signed verified record onto the public Observation Log — instantly queryable at /merchant/{domain} — plus a live badge (served by Onyx, so it can't be faked or staled) and a machine-readable status URL agents check before they pay you. Valid 90 days, renewable. This attests your domain PASSED published checks, like a CA certificate — Onyx never claims you are 'honest' or 'safe'; the value is a neutral, verifiable, public presence agents can trust. (price: $2.00 USDC, tier: premium) Required: domain.

onyx_verify_explain(now_unix, x_payment_b64, payment_payload, payment_requirements)

Diagnose a failing x402 v2 /verify. Decodes a captured X-PAYMENT header, runs 10 rules (decode, schema, network/asset/payTo match, value sufficiency, EIP-3009 timing, signature shape, scheme) against expected paymentRequirements, and returns the FIRST failing rule with a plain-English fix. Catches the common case where the facilitator returns bare HTTP 402 (no body) because of JWT or schema fail upstream of the verifier. Stdlib-only, no install, no network. (price: $0 USDC, tier: free) Required: payment_requirements.

onyx_x402_receipt_verify(network, tx_hash, expected_to, expected_from, expected_amount_usdc)

Verify an x402 USDC settlement on Base or Base Sepolia. Given a tx hash, decodes the USDC Transfer log and confirms (or refutes) a claim of the form: 'tx X moved $Y USDC from A to B'. Returns success status, actual decoded values, and a clear discrepancy report if any field doesn't match. Free tier — useful for agents reconciling spend and operators auditing inbound payments. (price: $0 USDC, tier: free) Required: tx_hash.

rhinogent_identity(address)

Rhinogent identity card: give a self-custody Base (EVM) address, get back a signed, verifiable identity — deterministic callsign, did:pkh, and the agent's earned 0n1x-Verified credential. Keys never leave the agent; this issues only the public signed identity. The front door of the agent identity wallet. (price: $0.00 USDC, tier: free) Required: address.

rhinogent_mandate(agent, purpose, principal, expires_at, velocity_max, daily_cap_usdc, spend_max_usdc, allowed_actions, allowed_domains, allowed_merchants)

Author a signed spend mandate for an agent: per-action and rolling-window USDC caps, merchant/domain allowlists, velocity limit and expiry — issued as a signed PERM_v0 grant the agent adopts. 'Transacts autonomously, within the boundaries you define.' (price: $0.00 USDC, tier: free) Required: agent.

rhinogent_verify_counterparty(brand, domain, expected_price)

Know-your-counterparty for agents. Before your agent pays a merchant, get Ed25519-signed raw facts about who it's paying: domain registration age, live TLS cert, reachability + off-domain redirects, brand-impersonation similarity, and observed price vs expected. Facts only (never 'legit/scam') — the one check every other agent wallet skips. (price: $0.25 USDC, tier: premium) Required: domain.

Last successful function declaration observed on 2026-08-13. Source: https://onyx-actions.onrender.com/mcp/. We list what the server declared; we do not call any of these functions.

Endpoint status observed on 2026-08-13. Source: https://onyx-actions.onrender.com/mcp/.

Signals

These are separate measurements of different things. They are deliberately not combined into one score, because a popularity number that mixes website traffic with saves and stars cannot be checked or acted on.

Where to get it

• Repository — https://github.com/dimitrilaouanis-tech/onyx-mcp
• Website — https://onyx-actions.onrender.com
• Remote endpoint (streamable-http) — https://onyx-actions.onrender.com/mcp/

Related, by what their authors tagged them

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These share tags the maintainers applied themselves, such as proof-of-execution, signed-receipts, agentic-payments, base. Common tags like "mcp" or "ai" are ignored for this: agreeing with six hundred other projects is not a similarity.

This is not a recommendation and not a test result. It is a map of what the authors said their work is about.

How the author describes it

Topics the maintainer set on GitHub: agent-economy, agent-payments, agent-verification, agentic-commerce, agentic-payments, ai-agents, base, erc-8004, mcp, mcp-server, model-context-protocol, paid-mcp, proof-of-execution, rug-scanner, signed-receipts, solana, token-risk-scan, tx-explainer, usdc, x402.