Onyx MCP server

• onyx_aeo_scoreFree

  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)

• onyx_agent_economy_indexFree

  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_registryFree

  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_verifyFree

  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)

• onyx_ai_visibilityFree

  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)

• onyx_attestation_verifyFree

  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)

• onyx_contract_auditFree

  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)

• onyx_ecosystem_intelFree

  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_lookupFree

  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_exchangeFree

  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)

• onyx_mail_checkFree

  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)

• onyx_mail_sendwrite actionFree

  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)

• onyx_market_rankFree

  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)

• onyx_merchant_fact_checkFree

  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)

• onyx_payment_gateFree

  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)

• onyx_perm_checkFree

  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)

• onyx_perm_grantFree

  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)

• onyx_preflightFree

  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)

• onyx_research_intelFree

  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)

• onyx_retail_price_checkFree

  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)

• onyx_secure_paymentFree

  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)

• onyx_security_flagsFree

  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_guardFree

  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)

• onyx_token_riskFree

  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)

• onyx_track_recordFree

  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_guardFree

  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)

• onyx_tx_preflightFree

  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)

• onyx_verified_issueFree

  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)

• onyx_verify_explainFree

  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)

• onyx_x402_receipt_verifyFree

  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)

• rhinogent_identityFree

  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)

• rhinogent_mandateFree

  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)

• rhinogent_verify_counterpartyFree

  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)

• –Code scanremote-only server, no package to scann/a
• Live reliabilityremote reachable in 1549ms20/20
• Tool poisoning33 tool descriptions checked15/15
• Auth qualityopen endpoint exposes 1 write-action tools with no auth3/15
• Maintenancelast push 57 days ago12/15
• Maintainer identityregistry namespace matches repository owner6/10

Safety score

75/100

higher than 45% of 48,255 servers

Tools

33

the typical server has 7

Tools that change things

3%

typical: 0%. Fewer write tools means less an agent can break

Uptime

100%

of our recent checks; the typical remote server answers 100%

Response time

432 ms

faster than 34% of 30,031 servers

GitHub stars

2

more than 75% of 28,688 servers

Onyx: common questions

Is Onyx MCP server safe?

Mostly: it is graded B (75/100). Read the Onyx safety report

How do I install Onyx?

It runs remotely at onyx-actions.onrender.com. Add it to Claude Code, Cursor, VS Code or Claude Desktop with the snippets above, or call it through the mcp.market gateway without installing anything.

Does Onyx need an API key?

Not as far as the registry entry and our scan can tell: no credentials are declared or required.

Is Onyx maintained?

The last commit was 95 days ago (2026-07-31). The latest release is v0.4.0.

Is Onyx up?

100% of our last 28 checks got an answer. We check remote servers about four times a day.

How does Onyx compare with other MCP servers?

safety score 75/100 (higher than 45% of 48,255 servers); tools 33 (the typical server has 7); tools that change things 3% (typical: 0%. Fewer write tools means less an agent can break). Full comparison.