Every agent-payable API.

Check an x402 seller before you pay it. Probes the endpoint now, checks that its payment can actually succeed (token EIP-712 domain, payTo), and adds its 30-day uptime from our monitor of paid Bazaar listings, how many distinct buyers paid it, and how its price compares with similar listings, with cheaper well-used alternatives. Returns a verdict (ok, caution, avoid) with the reasons.

Payability preflight: audits an x402 seller's 402 challenge

x402 Price Benchmark what this market actually transact. Hosted API via Speedbot; provider price plus 8% fee. version=external_api_7170e963c4c6254c01805cab2760bdc3 checksum=7170e963c4c6254c01805cab2760bdc35cd68cc75732aec9f7ba1813adaa7409 listing=3c7c58e6983e6f825539d72d4dabbf6ff1c166ad2163d37f1ac4a0c2db32467c

Premium content. Independently monitored by x402-list.com: 100% uptime since Oct 27, 2026, 14/14 x402 compliance checks (as of Oct 31, 2026). Evidence: https://x402-list.com/services/agentx402pay

x402 paywall template for any HTTP API (download). Download the x402 Proxy Template v1.0.0 (zip, MIT): a Cloudflare Worker that puts an x402 paywall (USDC on Base, x402 v2 + v1) in front of any HTTP API from one config file, with Bazaar discovery metadata, OpenAPI, remote + stdio MCP, OpenAPI importer, mock API, smoke test, 11 tests, quickstart and deploy guide.

Live BTC/ETH/SOL prices + the Crypto Fear & Greed Index in one call. Sourced from CoinGecko and alternative.me public data, combined for convenience.

Call before routing or accepting an x402 payment: multi-rail health (facilitators, settlement, market) across x402 rails (JSON).

Call before routing or accepting an x402 payment: multi-rail health (facilitators, settlement, market) across x402 rails (JSON).

On-page SEO audit for any live URL. Returns a 0-100 SEO score plus the raw signals behind it: title tag and meta description with their lengths, canonical URL, robots directives, the full H1-H3 heading map, image alt-text coverage, Open Graph and Twitter card completeness, and whether schema.org structured data is present. Fetches the live page on every call, so results reflect the page as it is now. Use it to audit a landing page, diagnose weak search rankings, or inspect a competitor.

Audit your x402 endpoint before buyers hit it. Checks that it answers 402 on the right method, that the payment options can actually be signed (EIP-712 domain of the token matches extra.name and extra.version), that the resource URL is the https URL buyers call, and that /openapi.json and /.well-known/x402 match. Includes the CDP validate verdict, whether the CDP Bazaar lists the endpoint, its payers in 30 days, and its search rank and competitors' prices for up to 3 queries.

Parameter-free: the Blockchain IQ x402 Conformance Index in one call. The top 1,000 x402 sellers ranked by an A to F grade from our own daily unpaid probe of their listed endpoints: valid HTTP 402, x402 v2, payment terms, schema, 7-day uptime, price range, 30-day payers and calls, with method and sources. Dated each day; never sold when the probe is over 48 hours old. Use to screen endpoints for protocol conformance before an agent pays. JSON, no API key. $0.02 per call. Blockchain IQ.

Use when you sell an API over x402 and want it to pass Bazaar/CDP listing checks. Input: url (https x402 resource), method GET or POST. Output: JSON score 0-100, grade, per-check pass/warn/fail with fix hints (x402 v2 quote, accepts fields, USDC asset, payTo format and OFAC list, description quality, Bazaar schemas, header size, CORS, latency, openapi/llms.txt, ERC-8004) plus our measured uptime. Never pays. Example: ?url=https://1gateway.dev/v1/time/convert

Find the best x402 API for a task. Describe what you need (for example "remove the background from a photo") and get the matching sellers from the CDP Bazaar ranked by relevance, how many distinct buyers paid them in 30 days, their uptime measured by our monitor every 6 hours, and price. Each result has its price, payers, uptime, median latency and how to call it (method and example input).

x402 Service Index the full directory record for live p. Hosted API via Speedbot; provider price plus 8% fee. version=external_api_f1e23f468705020f057cf4cad5af4804 checksum=f1e23f468705020f057cf4cad5af48040228d0cb1eb2f30ac24b1f3e52a8cca5 listing=8bc51cbe53c13640db7ce41d8e544bada0cffc0ef1f61e0ec39ad6d4bdc3b094

x402 Settlement Review: Replay and Double Charge — Reviews pasted seller-side x402 code that accepts the PAYMENT-SIGNATURE header, talks to the facilitator and delivers the goods (the cash register), for the silent failures that double-charge a buyer, hand the goods to a stranger or bill the seller. It flags an expiry check that runs before the nonce lookup, a repeat path that delivers without proof the chain observer lacks, a repeat window taken from the buyer's validBefore instead of the sell…

Real LLM-backed text generation (Gemini), billed by output length (max $0.05/request)

Pay-per-use AI audio transcription API. Transcribe short MP3 and WAV audio files using Whisper Large V3 Turbo. No account or API key required. Pay with USDC on Base. 0.02 USDC per request. Maximum 120 seconds and 2 MB; MP3 and uncompressed PCM WAV only. Returns JSON: text, detected language, duration and timestamped segments. Charged only when a transcript is returned.

Trend insights for a topic, based on real Wikipedia page-view volume and momentum. Premium tier adds relatedTrends: other Wikipedia article titles matching the same search terms (title-similarity, not a curated semantic-relevance ranking). Not literal search/social trend data — see the response's `source` field.

Trend insights for a topic, with a premium tier for the full breakdown

Is this x402 endpoint trustworthy? Body {url}. Returns its latest x402 Trust Index grade (A/B/C) and run date, plus evidence from a real paid test call: 402 status, price seen, payTo, settlement tx hash, on-chain check, HTTP status after paying, latency, schema check, and delivery result. If the endpoint is not in the index you get status not_indexed. Raw data link included. Free grade-only: GET /trust/lookup?url=

Run a regular expression on a text: every match with its position and capture groups (named too), and the text with a replacement applied. RE2 syntax, which runs in linear time (no lookaround or backreferences).

Evaluate an arithmetic expression with 64 significant digits (no floating point surprises): operators, parentheses, powers, roots, logs, trigonometry, percentages, constants, units (5 inch to cm) and simple statistics.

Encode or decode text: base64, base64url, hex, URL (percent) encoding and HTML escaping.

The current time, or a given time, in one or more IANA time zones, with UTC offset, abbreviation, whether daylight saving time is in effect, and the weekday. Give a local time with from_tz to convert it, handling DST correctly.

MD5, SHA-1, SHA-256, SHA-512, SHA3-256 and Keccak-256 (Ethereum) of a text, or of bytes given as hex or base64, as hex and base64.

Validate a JSON value against a JSON Schema (draft-07 and 2019-09 keywords, formats such as email, uri, date-time) and list every error with its path. Patterns run on RE2, so a schema cannot stall the check.

Check whether a phone number is valid and possible, find its country and type (mobile, fixed line, toll free and others), and format it as E.164, international and national (libphonenumber metadata).

Count the tokens of a text for OpenAI models (o200k_base for GPT-4o and later, cl100k_base for GPT-4), with characters, words and lines, to size prompts and estimate cost.

Explain a cron expression in plain English and list its next run times in a time zone (5 or 6 fields, with ranges, steps, L, W and #).

Decode a JSON Web Token's header and claims, and say when it was issued, when it expires, whether it has expired and in how many seconds it will. The signature is not verified.

Compare two texts by lines, words or characters: what was added and removed, and a unified diff for lines.

Add or subtract an ISO 8601 duration (P1M, P2W, PT36H) to a date, months clamped to the month's end; or count the days, weeks, calendar months, years, seconds and business days (Monday to Friday, less a country's public holidays) between two dates. Also the weekday, ISO week and day of year.

Holidays of a country (and optionally a state or region) in a year, with date, name and type (public, bank, school, optional, observance), from the date-holidays data for about 200 countries.

Convert a value between units of length, mass, volume, temperature, speed, area, energy, power, pressure, data size, time and more (mathjs units), such as mi to km, degF to degC, GB to MiB, kWh to J.

Generate random IDs from a cryptographic source: UUID v4, UUID v7 (time ordered), ULID or nanoid, up to 100 at a time.

YouTube video metadata in one call: title, channel name and id, duration, upload date, view and like counts, description, thumbnail URL, the chapter list with start and end times, and the language plus kind (manual or auto) of every available caption track. Never downloads media. Use it to check a video's length or caption availability before paying for a transcript, or to enrich a bare video link with real facts.

YouTube video transcript extraction with per-segment timing. Returns the caption track as timed segments (start, duration, text) plus the full plain text, or as SRT subtitles. Uses the creator's manual captions when they exist and falls back to YouTube automatic captions. Never downloads media, so it stays fast and light. Cached per video and language. Use it to summarize a talk, quote a video with timestamps, or search inside video content.

Native and (optional) ERC-20 token balance for a wallet address across major EVM chains (base, ethereum, polygon, arbitrum, optimism)

Native and (optional) ERC-20 token balance for a wallet address across major EVM chains (base, ethereum, polygon, arbitrum, optimism)

Live current weather conditions for any city, sourced from Open-Meteo

Live current weather conditions for any city, sourced from Open-Meteo

Ranked news brief for any topic, refreshed every 15 minutes: the most-corroborated recent headlines, each with source, URL, published time, age in minutes and an importance score computed from how many independent news engines surfaced it and how fresh it is. Zero-LLM, deterministic, no API key. Use it for a market or crypto morning brief, monitoring a company or keyword, or grounding a summary in dated sources.

Fetch one public web page and return its readable content as clean text or markdown, with JavaScript executed, so the result reads like the page a human sees. The retrieval half of research: pair it with /search to go from a query to grounded page text. Returns the content, its length, the final URL and the HTTP status. Truncate with max_chars.

Run up to 5 web searches in one call and get a results block per query. Saves the round trips an agent would otherwise make when a task needs several lookups (multi-entity research, comparison, fan-out). Same engine as /search; each query returns up to 10 trimmed results.

Real-time web search (via Exa) — ranked results with title, URL, published date, author, and relevance score for a query

Prepaid Search credits: pay once, get a key with 10 percent extra credit, no per-call signing.

Research answer: ask a question in plain language and get a short written answer from the live web, with numbered citations. It searches, reads the top result pages, and writes 2 to 4 sentences using only what those pages say; every claim carries the number of its source, and an answer the sources cannot support is refused. When the sources do not answer the question you are not charged. Use it instead of search, then fetch, then read.

Academic and scientific paper search, keyless: one query across arXiv, PubMed, Semantic Scholar, OpenAlex and Google Scholar via a dedicated SearXNG science index. Each hit carries title, URL, authors, publication date, journal/venue, DOI and a PDF link where available, plus a snippet. Use it for a literature scan, citation hunting, or grounding a claim in primary research.

Web search that returns structured SERP results as JSON. Runs on a dedicated SearXNG instance aggregating multiple engines, so there is no per-engine API key, quota or HTML scraping to manage. Each result carries title, URL, snippet, the source engine and a published date where available. Choose general web, news, or image results, up to 10 per call. Use it to ground an answer in current web sources, research a topic, or monitor news on a query.

Web search with the page text already extracted: one call returns the top results for a query AND the readable content of each result page (JavaScript rendered, markdown or text, truncated to max_chars). What an agent needs to answer a question with sources without a second round of fetches. Up to 5 pages per call, fetched in parallel.