# onyx-mcp MCP server

12 paid agent tools over x402 USDC on Base — captcha, SMS OTP, HLR, URL text, DNS, email, more.

## Links
- Registry page: https://www.getdrio.com/mcp/io-github-dimitrilaouanis-tech-onyx-mcp
- Repository: https://github.com/dimitrilaouanis-tech/onyx-mcp
- Website: https://onyx-actions.onrender.com

## Install
- Endpoint: https://onyx-actions.onrender.com/mcp/
- Auth: Not captured

## Setup notes
- Remote endpoint: https://onyx-actions.onrender.com/mcp/

## Tools
- onyx_agent_budget_tracker - Per-wallet USDC spend tracker. Given a wallet address and direction (outflows / inflows / both), scans USDC Transfer events on Base + Sepolia and returns: total volume, settlement count, top recipients with cumulative spend, hourly histogram of recent activity, average ticket size. Free tier — extension of onyx_agent_id. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_agent_id - Look up an agent (EVM wallet) and return a reputation card: x402-style USDC settlements in the last ~24h window (50k Base blocks), distinct recipients (paid-service operators), networks used, total volume, and 0-100 reputation score with reasoning. Reads Base + Base Sepolia public RPCs (no key). Free tier — useful for tools deciding rate limits, returning-customer discounts, or trust extension. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_agent_workflow - Run a multi-step workflow across Onyx tools in one paid call. Each step names a tool and its args; later steps can reference earlier outputs via {"$ref": "step_N.field"} or {"$prev": "field"}. Saves agents the round-trip + per-call gas of N separate x402 settles when they know the chain in advance — e.g. validate email → check domain DNS → solve captcha → fetch SMS OTP, all atomic. Stops on first step error and returns partial results. Cheaper than the unit-call sum because it bundles. (price: $0.020 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_aml_screen - KYC/AML sanctions + risk screen for any EVM address. Returns OFAC sanctions hit (via Chainalysis on-chain oracle), 0-100 risk score, verdict (sanctioned/safe/caution/high_risk/blocked), and ranked risk_factors (address age, transaction throughput, contract status, mixer interaction). Designed for Permitted Payment Stablecoin Issuers, agent-payment platforms, and any compliance gate forced by the GENIUS Act (July 2026). Sub-second latency. Coinbase's PROJECT-IDEAS.md explicitly calls for this primitive. (price: $0.25 USDC, tier: premium) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_base_token_risk_scan - Risk-scan any ERC-20 token on Base mainnet. Returns ownership status (renounced or active owner address), mint authority (still mintable?), top-1 / top-10 holder concentration via balanceOf probes, contract age in days, basic honeypot signal (eth_call swapExactETHForTokens against Aerodrome to detect transfer blocks), and a 0-100 risk score with verdict (safe / caution / high_risk). Use before a trading agent buys a freshly minted token — saves blowing the entire position on a rug. Direct equivalent of OATP's Solana token_risk_scan ($0.50, 980 unique paying agents). Onyx ships at $0.25 — first on Base mainnet. (price: $0.25 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_base_tx_decode - Fetch a Base mainnet transaction by hash and return a human-readable summary: from/to, value (ETH + USD-est), gas used, status, block, input data length, and the function selector decoded if it matches a known signature. Use when a trading agent needs to inspect a tx before or after settlement — pairs with onyx_token_metadata for full context. Reads from Base's public RPC (no key needed). Demo mode returns a synthetic record. (price: $0.002 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_base_tx_explainer - Decode a Base mainnet transaction into a human-readable summary. Returns a one-line plain-English description of what happened (token transfers, swaps, approvals, contract deploys), ERC-20 transfer events with symbol resolution, balance changes per address, the function selector + decoded method name where it matches a known signature, gas used, fee in ETH, and tx status. Use when a trading agent needs to verify what a tx actually did before/after settlement, or when a wallet agent needs to explain a tx to its user. Direct equivalent of OATP's Solana tx_explainer ($0.10, 1,350 unique paying agents) — Onyx is the first to ship this on Base mainnet at $0.05. (price: $0.05 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_base_tx_simulator - Simulate a Base mainnet transaction before sending it. Returns success/revert prediction, the revert reason if any, decoded return data, and an estimated gas figure. Use as a pre-flight check inside a trading agent's tool-call dispatcher — agents should simulate before signing to avoid paying gas on a doomed tx. Direct equivalent of OATP's Solana tx_simulator ($0.20, 1,304 unique paying agents) — Onyx is the first to ship this on Base mainnet at $0.10. Read-only — never submits. (price: $0.10 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_bazaar_compare - Side-by-side comparison of paid agent tools across the x402 ecosystem. Filter by keyword (e.g. 'captcha', 'tx_explainer', 'aml', 'sms', 'browser') and network ('Base' / 'Solana' / etc.), rank by price, 30-day call volume, or unique payer count, and get cheapest/most-used picks. Reads Coinbase Bazaar via the public Onyx mirror — refreshed every 15 minutes. Free tier. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_bazaar_submit - Indexability audit for any x402 service. Inspects the published surface (/openapi.json, /.well-known/x402.json, /manifest) against what Coinbase Bazaar's discovery crawler looks for, and returns a structured checklist: what's present, what's missing, what to fix. Crawler is poll-based — this tool documents the criteria, doesn't force-submit. Free tier. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_browser_click - Click the first visible button or link whose text matches the query (case-insensitive substring match). Returns whether a match was found and the matched element's text + href. Use after onyx_browser_extract to act on what the page advertised. Demo mode returns synthetic OK. (price: $0.003 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_browser_eval - Evaluate a JavaScript expression on the current CDP-controlled Chrome page and return the result by value. Use as a power-tool when the specific click/extract/type tools don't fit — pull deeply nested DOM data, dispatch synthetic events, read computed styles. Demo mode echoes the expression length without executing. (price: $0.004 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_browser_extract - Read the current CDP-controlled Chrome page and return the visible text content plus a structured summary of clickable elements: buttons, links (with hrefs), inputs (with names/placeholders/types). Use when an agent needs to plan its next action — list what's on the page without screenshotting + vision-modeling. Cheap, structured, deterministic. Demo mode returns a plausible synthetic page summary. (price: $0.003 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_browser_navigate - Navigate a Chrome DevTools Protocol session to a target URL and wait for load. Returns the final URL after redirects, page title, and elapsed wait time. Use as the first step of a browser-agent workflow — screenshot/click/type tools below act on whatever page this lands on. Demo mode (default in cloud) returns a plausible synthetic result; self-host with ONYX_CDP_URL pointed at your Chrome (--remote-debugging-port=9222) for real navigation. (price: $0.005 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_browser_screenshot - Capture a PNG screenshot of the current CDP-controlled Chrome page and return it as base64. Use to feed a vision-LLM (Claude / GPT-4V) for screen-understanding agents, or to archive an action's visual result. Returns also the page title, URL, and viewport dimensions. Cap of 1MB returned. Demo mode returns a synthetic 1×1 PNG; self-host with ONYX_CDP_URL for real captures. (price: $0.008 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_browser_type - Find an input/textarea/select on the current CDP page by its name, id, or visible label, set its value via the React-safe native setter, and fire input + change events so frameworks like React/Vue see the update. Use after onyx_browser_navigate when an agent fills a form. Returns the field selector matched and the final value. Demo mode returns synthetic OK. (price: $0.002 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_dns_lookup - Resolve a domain to its A/AAAA records, or reverse-resolve an IP to its hostname. Useful for validating a domain exists before scraping, checking if two domains share infrastructure, mapping CDN origins, or doing safety lookups before agents call third-party APIs. Returns IPv4, IPv6, canonical hostname, and resolution time. Powered by stdlib so results are whatever the host's DNS resolver returns — typically 20-100ms. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_email_validate - Validate an email address: RFC-5322 syntax check, domain DNS resolution (does the domain exist?), and disposable-provider detection (Mailinator, 10minutemail, GuerrillaMail, etc.). Returns a single confidence verdict plus the underlying signals so agents can decide whether to send. Use before mailing list signups, password-reset flows, or sales-lead capture to filter out trash addresses cheaply. ~30-80ms typical. (price: $0.002 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_ens_resolve - Resolve an ENS name to its current Ethereum mainnet address (or vice versa). Returns the canonical address, avatar URL if set, and the resolver contract that returned it. Use when an agent encounters a human-readable name like 'vitalik.eth' and needs to send funds or validate identity. Reads via the public ensideas API (no key, no rate-limit pain for typical agent traffic). ~200-500ms. (price: $0.002 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_facilitator_health - Live up/down + latency probe for all 5 known x402 facilitators (Coinbase CDP, x402.org public, xpay.sh, cronos-x402, faremeter). Returns per-facilitator status, response time, capabilities probe, plus ecosystem-wide health score. Free tier — agents shouldn't hardcode a single facilitator; this lets them pick a live one. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_fact_check - Fact-check any claim by fetching real-time web evidence. Returns supporting sources, contradicting sources, a 0-100 confidence score, and a short summary. Use for prediction-market resolvers, news-fact agents, journalist-bot pipelines, or any agent that needs to verify a statement before acting on it. Sub-second latency, no API key on the caller side. Coinbase PROJECT-IDEAS.md explicitly calls for this primitive. (price: $0.05 USDC, tier: premium) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_fx_convert - Convert between any two fiat currencies (USD, EUR, GBP, JPY, BRL, USDC-equivalent, 160+ ISO-4217 codes) at the current mid-market rate. Returns both the rate and the converted amount, plus the rate's last update timestamp. Use when an agent needs to price a service in another currency, normalize multi-currency invoices, or convert x402 USDC amounts to local fiat for human-readable receipts. Powered by open.er-api.com (free tier, no key). ~150-400ms. Demo mode returns USD-EUR @ 0.92 for testing. (price: $0.002 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_hash_compute - Compute md5, sha1, sha256, sha512, and sha3-256 of any text or base64-encoded bytes. Returns each digest as both hex and base64. Use for content-addressed lookups, dedupe keys, signature verification support, or fingerprinting. Stdlib-only — runs locally, never logs input. <2ms. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_html_meta - Fetch a URL and extract OpenGraph + Twitter Card + standard meta tags: og:title, og:description, og:image, og:type, twitter:card, twitter:image, canonical link, favicon, JSON-LD blocks. Use when an agent needs to preview a link before sharing, build a citation card, or detect spam/ads via meta-tag fingerprints. Stripped of HTML noise. ~150-500ms typical. (price: $0.002 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_ip_geolocate - Geolocate any public IPv4/IPv6 address — country, region, city, lat/lon, timezone, ISP, ASN, mobile/proxy/hosting flags. Useful for filtering traffic by country, detecting datacenter/VPN egress, fraud scoring, or deciding which regional endpoint to route an agent through. Backed by ip-api.com (free tier, ~1k requests/min). ~80-200ms typical. Demo mode returns a plausible US record so the payment loop can be tested without burning the upstream rate limit. (price: $0.002 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_jwt_decode - Decode a JWT (header + payload) without verifying the signature. Returns the algorithm, key id, all claims (iss, sub, aud, exp, iat, nbf, custom), expiry status, and any structural anomalies. Use when an agent receives a token from an external API and needs to inspect it for routing, expiry, or audit logging. Stdlib-only — runs locally, never sends the token anywhere. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_mcp_catalog_diff - Side-by-side tool catalog diff between any two MCP servers. Fetches each server's /manifest (with /openapi.json fallback), normalizes the tool lists, and returns: only-in-A, only-in-B, same in both, price delta, schema delta. Free tier — useful for competitor analysis, regression detection, and migration planning. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_mcp_health - Probe any public MCP / x402 server and return a structured health snapshot: endpoint latencies, content types, MCP discovery surface, x402 readiness, OAuth DCR advertisement, and a 0-100 composite reliability score. Stdlib-only. SSRF-hardened — refuses private, loopback, link-local, and reserved address ranges. Free tier, no key. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_mcp_meta_call - Pre-flight inspector for ANY x402 tool call. Pass target URL + optional caller wallet, get back: live 402 price, recommended chain (via chain_picker logic), live facilitator health, caller reputation (via agent_id logic), and a green/yellow/red GO signal. Free tier — the universal preflight that lets agents decide before they sign. v2 (paid) will broker the actual settlement and proxy the response. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_mcp_oauth_audit - OAuth 2.1 + RFC 7591 DCR compliance audit for any MCP server. Probes the 5 standard discovery + registration + token endpoints, validates each against the relevant RFC, returns a composite 0-100 score and remediation list. Free tier — useful for MCP operators preparing for ChatGPT custom-connector / Claude Managed Agents discovery. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_mcp_registry_status - Cross-registry listing audit for any MCP server. Checks Coinbase Bazaar (x402 discovery), Smithery, Glama, the official MCP Registry, and the awesome-mcp-servers list. Returns per-registry status + coverage score 0-100 + remediation suggestions for unlisted registries. Free tier. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_password_strength - Score password strength on a 0-100 scale. Returns Shannon entropy (bits), character-class diversity, length, common-pattern detection (sequences, repeats, dictionary-likeness), and a verdict (very_weak / weak / fair / strong / very_strong). Use when an agent generates passwords for accounts it creates, or when validating user-supplied credentials. Stdlib-only — runs locally, never sends the password anywhere. <5ms. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_pm_settlement_watch - Prediction-market state lookup — current odds, volume, liquidity, resolution state, and anomaly flags for any market on Polymarket or Manifold. Pass a market slug or full URL. Use for arb agents watching for mispriced events, copy-trading agents tracking whales, or settlement-resolver agents that pay only on a final outcome. Coinbase PROJECT-IDEAS.md explicitly calls for this primitive. (price: $0.005 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_robots_check - Fetch a domain's robots.txt and report whether a given path is allowed for a given user-agent. Returns the raw robots.txt text, the matched rule, the crawl-delay if specified, and a clean allow/disallow verdict. Use when an agent does web scraping and wants to be polite — saves bans, saves CAPTCHAs, saves drama. ~50-200ms. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_skill_bundle - Plan a multi-tool agent workflow under one x402 budget cap. Given a list of tool endpoints (any x402 server) and a max-spend cap, returns: unified cost preview (sum of declared prices), per-step prerequisites, estimated total settlement count, and whether the bundle fits the cap. v1 = analysis card (free); v2 = actually brokers settlement. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_solana_jupiter_quote - Best-route swap quote on Solana via Jupiter aggregator. Pass inputMint + outputMint + amount (in input mint's smallest units) and get the best route across all Solana DEXes (Orca, Raydium, Meteora, Phoenix, Lifinity, etc.) with price impact, expected output, intermediate hops, and slippage. Use BEFORE every Solana swap to lock execution price. Cheaper than every alternative — Jupiter's API is free but requires no API key tracking; we charge $0.001 USDC per quote with no signup. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_solana_token_metadata - Resolve name + symbol + decimals + total supply for any SPL token on Solana mainnet. Reads the SPL Mint account directly + derives the Metaplex metadata PDA for human-readable name/symbol. Pairs with onyx_solana_token_risk_scan for full pre-trade safety. Cheaper than OATP ($0.001) and Helius ($0.001 + API key) — Onyx uses free public RPC and bills only the agent's wallet. (price: $0.002 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_solana_token_risk_scan - Rug-vector risk scan for any SPL token on Solana mainnet. Checks mint authority (active = can mint unlimited supply), freeze authority (active = can freeze any holder's wallet), top-10 holder concentration (whale risk), supply rationality, and pump.fun bonded/unbonded state. Returns 0-100 risk score + verdict (safe/caution/high_risk/likely_rug) + ranked risk_factors. Designed for memecoin/sniper/MEV agents that need a sub-second pre-trade gate. OATP charges $0.50 for the same primitive — Onyx is half-price, no API key, USDC-direct. (price: $0.25 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_solana_tx_explainer - Decode a Solana mainnet transaction into a human-readable summary. Returns a one-line plain-English description (SPL transfers, swaps, stake ops, NFT moves), parsed token-balance pre/post per account, SOL-balance deltas, programs invoked, compute units used, and fee. Use when a trading agent needs to verify a Solana tx actually did what it claims, or when a wallet agent needs to explain an action to its user. Direct equivalent of OATP's $0.10 service (1,350+ unique paying agents) at half the price, no API key, x402-native. (price: $0.05 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_solana_wallet_activity - Recent on-chain activity for any Solana wallet. Returns the last N signatures (default 25, max 100) with slot, block_time, status, fee, and best-effort program/action classification (swap, transfer, stake, NFT). Designed for whale-watching, copy-trading, and risk-monitoring agents that need a sub-second feed without managing their own RPC. Cheaper than Helius webhooks ($25/mo) and Birdeye wallet-portfolio ($0.002 + API key). x402-direct, no signup. (price: $0.002 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_solve_captcha - Solve an image-based text captcha and return the recognized text. Works on standard alphanumeric captchas (web signup forms, login walls, scraping checkpoints). OCR via ddddocr — typical p50 latency 30-80ms, 70-90% accuracy on common captcha fonts. Provide either an image URL we fetch on your behalf, or raw base64 image bytes if you already have them. Use when an agent encounters a captcha mid-task and needs to continue without human intervention. Cheaper and faster than 2captcha for simple image captchas; not designed for reCAPTCHA v2/v3 or hCaptcha (those are interaction-based). (price: $0.003 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_token_metadata - ERC-20 token metadata lookup on Base mainnet: name, symbol, decimals, and total supply for any contract address. Use before transacting with a token agents discover at runtime — confirms the contract is a real ERC-20 and resolves human-readable identity. Reads via Base public RPC, ~150-300ms typical. Pairs with onyx_base_tx_decode for full token-flow context. No vendor key needed. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_url_parse - Parse any URL into structured components: scheme, host, port, path, query params (as both raw and decoded list), fragment, userinfo. Use when an agent needs to inspect, modify, or validate a URL — change a query param, strip tracking, normalize for caching. Stdlib only, no network calls, <1ms. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_url_text - Fetch any public URL and return the readable text content stripped of HTML/scripts/styles. Use when an agent needs to reason over a web page without rendering a browser — docs pages, articles, search-result snippets, GitHub READMEs. Returns plain text + page title + word count + final URL after redirects. Capped at 200kB output to keep token costs predictable. ~150-800ms typical depending on origin server. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_url_unshorten - Follow HTTP redirects on any URL and return the final destination + the full redirect chain. Use when an agent encounters a bit.ly/t.co/lnkd.in/ shortened link and needs to know where it actually goes before clicking. Returns each hop's status code, location, and final URL with status. Cap of 10 hops to prevent loops. ~100-400ms typical. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_user_agent_parse - Parse any HTTP User-Agent string into a structured record: browser name/version, OS name/version, device type (desktop/mobile/tablet/bot), rendering engine. Use for analytics, fraud scoring, or routing logic based on client capabilities. Stdlib regex only — works offline, no external lookups. <2ms. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_verify_explain - 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) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_whois - Domain whois via the modern RDAP protocol — registrar, creation/expiry dates, nameservers, registrant country, status flags. Use to vet a domain before agents transact with it (newly registered = higher fraud risk), check trademark conflicts, or confirm ownership transfer. Powered by rdap.org (no API key, free tier). ~200-500ms typical. (price: $0.001 USDC, tier: metered) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_x402_chain_picker - Pick the optimal chain for an x402 USDC payment. Given target amount + agent's available chains, ranks by facilitator support, live gas, finality time, and USDC contract maturity. Returns ranked list with explanations. Free tier — agents shouldn't hardcode 'base' when their wallet has L2 options. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_x402_demo_wallet - Dev-sandbox wallet helper for x402 testing. Generates a deterministic ephemeral Sepolia wallet (or accepts your address), reports ETH + USDC Sepolia balances, points to the Circle USDC Sepolia faucet, and emits a copy-paste env config for x402 client SDKs. SANDBOX ONLY — generated keys are deterministic and MUST NOT receive real value. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_x402_error_explain - Plain-English explainer for any HTTP error in an x402 / MCP flow. Pass the status code + response body (or headers), get back a diagnosis with specific cause and actionable fix. Covers FastAPI validation, OAuth2 DCR failures, EIP-712 signature errors, x402 spec error codes, and Coinbase facilitator-specific responses. Free tier — local logic, no network calls. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_x402_facilitators - Directory of known x402 facilitators (Coinbase CDP, x402.org public, xpay.sh, Cronos, Faremeter, others), each with live reachability probe, supported networks, payment auth scheme (JWT / open), and median latency. Agents use this to choose where to route /verify and /settle calls. Free tier — refreshes per call, no API key. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_x402_receipt_verify - 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) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_x402_simulate - Simulate an x402 v2 payment flow against any paid endpoint. Fetches the 402 challenge (or introspection card), parses paymentRequirements, generates a template X-PAYMENT payload with the exact fields an agent would need to sign (EIP-3009 authorization shape, validBefore window, asset address, recipient), and returns next-step guidance. Pure simulation — no keys, no signing, no payment. SSRF-hardened. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/
- onyx_x402_spec_lookup - Quick-reference into the x402 v2 protocol spec. Look up an error string, HTTP status, header name, payload field, or feature keyword and get the relevant spec snippet plus a plain-English fix. Replaces 30 minutes of spec-grepping with a single call. Free tier — embedded knowledge, no network. (price: $0 USDC, tier: free) Endpoint: https://onyx-actions.onrender.com/mcp/

## Resources
Not captured

## Prompts
Not captured

## Metadata
- Owner: io.github.dimitrilaouanis-tech
- Version: 0.2.0
- Runtime: Streamable Http
- Transports: HTTP
- License: Not captured
- Language: Not captured
- Stars: Not captured
- Updated: Apr 29, 2026
- Source: https://registry.modelcontextprotocol.io