x402-paywall-probe
x402.agentindex.world · 118 paid endpoints · listed 2026-10-27
Fresh operational audit of any public agent or paid API: reachability, latency, HTTP status, x402 challenge, price/network/payTo, OpenAPI, agent card and MCP manifest. Returns a 0-100 score, verdict and issues. Try GET /agent-health/sample.
livelast check 3 h ago
100%valid x402 answers, 72 h
$0.078USDC received on Base, 7 days
15distinct payers, 7 days
58.3score (0-100)
Paid endpoints
| Method | Endpoint | Price | Networks |
|---|---|---|---|
| GET | x402.agentindex.world/agent-health Fresh operational audit of any public agent or paid API: reachability, latency, HTTP status, x402 challenge, price/network/payTo, OpenAPI, agent card and MCP ma | $0.001 | Base |
| POST | x402.agentindex.world/base/block-number Latest Base mainnet block height via eth_blockNumber - the current chain tip. | $0.001 | Base |
| POST | x402.agentindex.world/base/chain-id Base mainnet chain ID (EIP-155) via eth_chainId - confirm which network you're actually talking to. | $0.001 | Base |
| POST | x402.agentindex.world/base/network-info Base mainnet network info in one call: chain ID, block height, and current gas price (wei and gwei). | $0.001 | Base |
| GET | x402.agentindex.world/can-pay Check whether a Base wallet holds enough USDC to pay an x402 amount (default $0.001). Returns balance, can_pay, shortfall. The checklist agents run before spend | $0.001 | Base |
| GET | x402.agentindex.world/crypto Live spot prices for crypto coins (BTC, ETH, SOL, ...) in USD or another fiat, with 24h change. Accepts tickers or CoinGecko ids. Try GET /crypto/sample. | $0.001 | Base |
| POST | x402.agentindex.world/decide Ask up to 20 typed yes/no, multiple-choice or ordinal-scale questions about one shared piece of context in a single call - each answered with a real probability | $0.001 | Base |
| POST | x402.agentindex.world/discover Find MCP servers matching a need, ranked by semantic similarity over a curated snapshot of MCP servers. Returns name, endpoint, description, source registry and | $0.001 | Base |
| POST | x402.agentindex.world/fraction/simplify Simplify a fraction to lowest terms and return its decimal value. | $0.001 | Base |
| GET | x402.agentindex.world/gas-price Read the live gas price, EIP-1559 base fee and estimated native-transfer cost on Base, Ethereum, Polygon, Arbitrum or Optimism. No RPC key or account. Try GET / | $0.001 | Base |
| POST | x402.agentindex.world/geo/bbox Bounding box (min/max lat and lon) enclosing a list of points. | $0.001 | Base |
| POST | x402.agentindex.world/geo/bearing Initial compass bearing (0-360 degrees, clockwise from true north) from point 1 to point 2. | $0.001 | Base |
| POST | x402.agentindex.world/geo/distance Great-circle distance between two lat/lon points (haversine formula). Returns km, mi or nm. | $0.001 | Base |
| POST | x402.agentindex.world/geo/dms Convert decimal degrees to degrees/minutes/seconds, or DMS back to decimal degrees. | $0.001 | Base |
| POST | x402.agentindex.world/geo/geohash Encode a lat/lon point into a geohash string (precision 1-12 characters). | $0.001 | Base |
| POST | x402.agentindex.world/geo/midpoint Geographic (great-circle) midpoint between two lat/lon points. | $0.001 | Base |
| POST | x402.agentindex.world/geo/point-in-polygon Ray-casting point-in-polygon test (planar approximation - fine for city/region-scale polygons). | $0.001 | Base |
| POST | x402.agentindex.world/guard Ask whether a tool call should run automatically, need human confirmation, or be denied, given the user's request - returns allow/ask/deny with a probability. A | $0.001 | Base |
| POST | x402.agentindex.world/json/flatten Flatten a nested JSON document into single-level dotted-path keys. | $0.001 | Base |
| POST | x402.agentindex.world/json/query Query a JSON document with a JSONPath expression. | $0.001 | Base |
| POST | x402.agentindex.world/json/schema-infer Infer a basic JSON Schema (types, object properties, array item type) from an example document. | $0.001 | Base |
| POST | x402.agentindex.world/json/validate Validate a JSON document against a JSON Schema. | $0.001 | Base |
| POST | x402.agentindex.world/llm/gpt-mini GPT Mini API - pay per call, no API key. OpenAI-format chat completions on openai/gpt-5.4-mini, pinned to OpenAI's own OpenRouter endpoint for reliability. You | $0.001 | Base |
| POST | x402.agentindex.world/llm/llama Llama API - pay per call, no API key. OpenAI-format chat completions on meta-llama/llama-4-maverick, pinned to DeepInfra for reliability. You sign a fixed price | $0.001 | Base |
| POST | x402.agentindex.world/money/allocate Split an integer amount of cents among N ratios with zero rounding loss (Fowler's allocation algorithm) - the parts always sum back to the original amount. | $0.001 | Base |
| POST | x402.agentindex.world/money/format Format a numeric amount with thousands separators, a chosen decimal precision and a currency symbol. | $0.001 | Base |
| POST | x402.agentindex.world/news Top Hacker News headlines right now - title, URL, score, comments. Fresh links for agents that need current tech/startup signal. Try GET /news/sample. | $0.001 | Base |
| POST | x402.agentindex.world/number/ordinal Convert an integer to its English ordinal form (1st, 2nd, 3rd, 4th, 11th, 21st...). | $0.001 | Base |
| POST | x402.agentindex.world/number/radix Convert a number's string representation from one base (2-36) to another. | $0.001 | Base |
| POST | x402.agentindex.world/number/roman Convert an integer (1-3999) to a Roman numeral, or a Roman numeral back to an integer. | $0.001 | Base |
| POST | x402.agentindex.world/number/words Convert an integer into English words. | $0.001 | Base |
| GET | x402.agentindex.world/probe Probe any public URL and report if it is an x402 paywall - price, network, payTo, scheme. Shop paywalls before you spend. Try GET /probe/sample. | $0.001 | Base |
| POST | x402.agentindex.world/rank Rank up to 50 documents by relevance to a query in a single call - each document returned with its relevance probability, sorted highest first. Powered by Jev ( | $0.001 | Base |
| POST | x402.agentindex.world/regex/replace Replace regular expression matches in text, with an optional max-replacement count. | $0.001 | Base |
| POST | x402.agentindex.world/regex/test Test a regular expression against text; returns match status, capture groups and span. | $0.001 | Base |
| POST | x402.agentindex.world/stats/correlation Pearson correlation coefficient between two equal-length numeric series. | $0.001 | Base |
| POST | x402.agentindex.world/stats/percentile Nth percentile of a list of numbers (linear interpolation between closest ranks). | $0.001 | Base |
| POST | x402.agentindex.world/stats/regression Ordinary least squares simple linear regression (y = slope*x + intercept) with R-squared. | $0.001 | Base |
| POST | x402.agentindex.world/stats/summary Descriptive statistics for a list of numbers: count, mean, median, sample stdev/variance, min, max. | $0.001 | Base |
| POST | x402.agentindex.world/text/case Convert text between case styles: snake_case, camelCase, PascalCase, kebab-case, Title Case, CONSTANT_CASE. | $0.001 | Base |
| POST | x402.agentindex.world/text/diff Unified line diff between two texts, plus an overall similarity ratio (0-1). | $0.001 | Base |
| POST | x402.agentindex.world/text/readability Flesch Reading Ease and Flesch-Kincaid Grade Level scores for English text (standard public formulas, heuristic syllable counting). | $0.001 | Base |
| POST | x402.agentindex.world/time/add Add a fixed duration (days/hours/minutes/seconds) to an ISO 8601 datetime. | $0.001 | Base |
| POST | x402.agentindex.world/time/between Duration between two ISO 8601 datetimes, as total seconds and a days/hours/minutes/seconds breakdown. | $0.001 | Base |
| POST | x402.agentindex.world/time/business-days Count weekdays (Mon-Fri) between two dates, inclusive of both endpoints. | $0.001 | Base |
| POST | x402.agentindex.world/time/convert Convert an ISO 8601 datetime from one IANA timezone to another (handles DST automatically). | $0.001 | Base |
| POST | x402.agentindex.world/time/format Format an ISO 8601 datetime using a strftime pattern. | $0.001 | Base |
| POST | x402.agentindex.world/time/iso-week ISO 8601 week number, ISO year and ISO weekday (1=Monday) for a date. | $0.001 | Base |
| POST | x402.agentindex.world/time/parse Parse a date/time string (ISO 8601 by default, or a given strptime format) into its components. | $0.001 | Base |
| POST | x402.agentindex.world/unit/convert Convert a value between units of length, mass, volume or temperature (C/F/K). | $0.001 | Base |
| POST | x402.agentindex.world/v1/chat/completions 437 models, no account, no API key, pay per call in USDC - OpenAI-compatible chat completions and AI inference gateway (Claude, GPT, Gemini, Llama, Mistral and | $0.001 | Base |
| POST | x402.agentindex.world/validate/ean EAN-8 or EAN-13 barcode checksum validation (auto-detected by length). | $0.001 | Base |
| POST | x402.agentindex.world/validate/imei IMEI (15-digit mobile device identifier) Luhn checksum validation. | $0.001 | Base |
| POST | x402.agentindex.world/validate/isbn ISBN-10 or ISBN-13 checksum validation (auto-detected by length). | $0.001 | Base |
| POST | x402.agentindex.world/validate/isin ISIN (ISO 6166 security identifier) Luhn checksum validation. | $0.001 | Base |
| POST | x402.agentindex.world/validate/routing US ABA bank routing number (9-digit) checksum validation. | $0.001 | Base |
| POST | x402.agentindex.world/validate/siret French SIRET (14-digit business establishment number) Luhn checksum validation. Note: the rare La Poste SIREN exception to the standard rule is not applied. | $0.001 | Base |
| POST | x402.agentindex.world/verify Check whether a source supports, contradicts, or gives insufficient information about a claim - a typed verdict with a real probability, not generated text. Pow | $0.001 | Base |
| GET | x402.agentindex.world/wallet-balance Read native coin and USDC balances for any EVM wallet on Base, Ethereum, Polygon, Arbitrum or Optimism, with atomic amounts and current block. No RPC key or acc | $0.001 | Base |
| GET | x402.agentindex.world/wallet-intelligence One call replaces wallet-balance and gas reads across Base, Ethereum, Polygon, Arbitrum and Optimism. Returns native and USDC balances, current blocks, fees and | $0.001 | Base |
| GET | x402.agentindex.world/weather Current weather and a 3-day forecast for any city or lat/lon - temperature, humidity, wind, conditions. No account, no API key. Try GET /weather/sample. | $0.001 | Base |
| POST | x402.agentindex.world/x402-echo Cheapest possible Base-mainnet x402 conformance call: settle $0.001 of USDC and receive payer identity, request echo and receipt. Built for agents testing walle | $0.001 | Base |
| POST | x402.agentindex.world/llm/claude-sonnet Claude Sonnet API - pay per call, no API key. OpenAI-format chat completions on anthropic/claude-sonnet-5.5, pinned to Anthropic's own OpenRouter endpoint for r | $0.001892 | Base |
| POST | x402.agentindex.world/encoding/detect Detect whether hex-encoded bytes are ASCII, UTF-8, or UTF-16 with a BOM, by decode-validity and BOM presence (not statistical language detection). | $0.002 | Base |
| POST | x402.agentindex.world/encoding/transcode Convert text between utf-8, base64, hex, URL-percent-encoding and ascii representations. | $0.002 | Base |
| POST | x402.agentindex.world/extract Extract structured data from a URL or raw text into strict JSON matching a schema you provide. Fields the content doesn't support come back null - never an inve | $0.002 | Base |
| POST | x402.agentindex.world/hash/hash Compute an MD5, SHA-1, SHA-256 or SHA-512 hex digest of text. | $0.002 | Base |
| POST | x402.agentindex.world/hash/hmac Compute an HMAC (MD5, SHA-1, SHA-256 or SHA-512) of text with a given key. | $0.002 | Base |
| POST | x402.agentindex.world/intent Intent detection: classify text as a question, request, complaint, compliment, or other, with a confidence score and an alternate label. Powered by Jev, with an | $0.002 | Base |
| POST | x402.agentindex.world/json/diff Recursive diff between two JSON documents: added, removed and changed paths. | $0.002 | Base |
| POST | x402.agentindex.world/language Language detection: identify which of 20 common languages (or "other") a text is written in, with a confidence score. Powered by Jev, with an automatic Groq-hos | $0.002 | Base |
| POST | x402.agentindex.world/pdf Extract a public PDF (by HTTPS URL or base64) into clean Markdown - headings and tables preserved via layout-aware parsing, plus title/author/page count/date me | $0.002 | Base |
| POST | x402.agentindex.world/sentiment Sentiment analysis: classify text as positive, negative, or neutral with a confidence score and an alternate label. Powered by Jev, with an automatic Groq-hoste | $0.002 | Base |
| POST | x402.agentindex.world/spam-check Spam detection: classify text as spam or not spam with a confidence score. Powered by Jev, with an automatic Groq-hosted LLM fallback if Jev is slow or unavaila | $0.002 | Base |
| POST | x402.agentindex.world/summarize Summarize a URL, raw text or HTML at the length you request - short, medium or long - with the source noted. Neutral and factual, no invented facts. Try GET /su | $0.002 | Base |
| POST | x402.agentindex.world/text/slug Slugify text: strip accents, lowercase, replace non-alphanumerics with a separator. | $0.002 | Base |
| POST | x402.agentindex.world/time/humanize Human-readable relative time ('2 hours ago', 'in 3 days') between a datetime and a reference (default now). | $0.002 | Base |
| POST | x402.agentindex.world/toxicity Toxicity detection: classify text as toxic or not toxic (hate speech, harassment, threats, severe offensive language) with a confidence score. Powered by Jev, w | $0.002 | Base |
| POST | x402.agentindex.world/translate Translate up to 200 text segments in a single call - the same result that would otherwise take 200 separate calls to translate a whole file. Markdown, HTML and | $0.002 | Base |
| POST | x402.agentindex.world/validate/iban ISO 13616 IBAN mod-97 checksum validation, with optional BIC (ISO 9362) format check. | $0.002 | Base |
| POST | x402.agentindex.world/validate/luhn Luhn (mod 10) checksum validation, as used by most payment card numbers. | $0.002 | Base |
| POST | x402.agentindex.world/validate/vin North American VIN check-digit validation (NHTSA standard, position 9) plus WMI manufacturer lookup for a small set of known codes. | $0.002 | Base |
| POST | x402.agentindex.world/web-read Fetch URL content as Markdown: read any web page and get clean Markdown - navigation, ads and boilerplate stripped, links resolved, plus a real token count. The | $0.002 | Base |
| POST | x402.agentindex.world/base/allowance ERC20 allowance on Base mainnet via RPC: how much a spender is approved to move from an owner balance, read with allowance(owner,spender) eth_call. | $0.003 | Base |
| POST | x402.agentindex.world/base/block Fetch a Base mainnet block header and transaction hashes by number, tag (latest/earliest/safe/finalized), or hash via eth_getBlockByNumber/eth_getBlockByHash. | $0.003 | Base |
| POST | x402.agentindex.world/base/code Check whether a Base mainnet address is a contract via eth_getCode - returns bytecode size, zero for an externally-owned account. | $0.003 | Base |
| POST | x402.agentindex.world/base/erc1155-balance ERC1155 multi-token balance for a wallet and token id on Base mainnet via balanceOf(address,uint256). | $0.003 | Base |
| POST | x402.agentindex.world/base/erc20-balance ERC20 token balance for a wallet on Base mainnet - balanceOf() and decimals() batched into one Multicall3 round trip. | $0.003 | Base |
| POST | x402.agentindex.world/base/live-balance Native ETH balance plus up to 20 ERC20 token balances for one wallet on Base mainnet, in a single Multicall3 round trip regardless of token count. | $0.003 | Base |
| POST | x402.agentindex.world/base/nft-owner Who owns this NFT? ERC721 owner lookup on Base mainnet via ownerOf(tokenId). | $0.003 | Base |
| POST | x402.agentindex.world/base/nonce Next transaction nonce for any Base mainnet wallet via eth_getTransactionCount - how many transactions it has sent. | $0.003 | Base |
| POST | x402.agentindex.world/base/quote Slippage estimate, swap quote, and best DEX price on Base - compares Uniswap v2, Uniswap v3, and Aerodrome on-chain via Multicall3, returns amount received, cho | $0.003 | Base |
| POST | x402.agentindex.world/base/total-supply Total supply for an ERC20 (normalized by decimals()) or ERC721 (raw count, no decimals) contract on Base mainnet. | $0.003 | Base |
| POST | x402.agentindex.world/classify Text classification with your own custom labels (2-20) - categorize a support ticket, a review, or any text into the best-fitting label, with a confidence score | $0.003 | Base |
| POST | x402.agentindex.world/pii-check PII detection: flag whether text contains personally identifiable information (name plus contact details, email, phone, address, government ID, financial accoun | $0.003 | Base |
| POST | x402.agentindex.world/base/estimate-gas Gas estimate for a Base mainnet swap or any other call (to/from/value/data) via eth_estimateGas, without broadcasting a transaction. | $0.004 | Base |
| POST | x402.agentindex.world/base/basename Resolve a Basename, Base's native ENS-equivalent, to its wallet address via the L2 Basenames resolver. | $0.005 | Base |
| POST | x402.agentindex.world/base/call Generic read-only eth_call against any Base mainnet contract - pass raw calldata, get the raw return data back. | $0.005 | Base |
| POST | x402.agentindex.world/base/can-sell Can I sell this token? Honeypot check that simulates a real buy then a real sell of a Base mainnet token in one atomic on-chain call via Uniswap V2 - if the sel | $0.005 | Base |
| POST | x402.agentindex.world/base/contract Contract introspection on Base mainnet - is it a contract, bytecode size, best-effort owner(), and whether it's a proxy. | $0.005 | Base |
Latest checks
| When | Endpoint | HTTP | ms | Result |
|---|---|---|---|---|
| 3 h ago | x402.agentindex.world/agent-claim | 402 | 135 | valid x402 v2 terms |
Income on Base (7 days)
| Day | Transfers | USDC | |
|---|---|---|---|
| 2026-11-02 | 1 | $0.001 | |
| 2026-11-01 | 12 | $0.014 | |
| 2026-10-31 | 3 | $0.003 | |
| 2026-10-30 | 10 | $0.016 | |
| 2026-10-29 | 12 | $0.021 | |
| 2026-10-28 | 7 | $0.008 | |
| 2026-10-27 | 10 | $0.013 | |
| 2026-10-26 | 2 | $0.002 |
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Claim it for free with
x402_provider_claim (sign with your payout address), and get an alert within minutes when it stops answering with x402_monitor_create ($5 for 30 days). Both work over MCP (https://logicnodes.io/mcp/v2) or POST https://logicnodes.io/v1/tools/<tool>.Income is all USDC received by the provider's payout address on Base, whatever the source. Score: 0-100: 50 x share of checks in the last 72 h that returned valid x402 payment terms + 30 x min(1, log10(1 + USDC received in 7 days) / 4) + 20 x min(1, log10(1 + distinct payers in 7 days) / 3). A provider never checked scores on income only; income is all USDC received by its payout address on Base, whatever the source. JSON: /v1/observatory/providers/x402.agentindex.world