x402-payment-test

Cheapest possible Base-mainnet x402 conformance call: settle $0.001 of USDC and receive payer identity, request echo and receipt. Built for agents testing wallets, Payment-Signature, facilitators and settlement. Try GET /x402-echo/sample.

Great-circle distance between two lat/lon points (haversine formula). Returns km, mi or nm.

Format an ISO 8601 datetime using a strftime pattern.

Count weekdays (Mon-Fri) between two dates, inclusive of both endpoints.

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.

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 /gas-price/sample.

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.

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 account. Try GET /wallet-balance/sample.

Latest Base mainnet block height via eth_blockNumber - the current chain tip.

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 invented or approximate value, and an unmatchable schema returns an explicit error. Try GET /extract/sample. Part of the AgentIndex content kit (pdf, web-read, extract, summarize, detect-language) - see GET /capabilities.

Convert an integer (1-3999) to a Roman numeral, or a Roman numeral back to an integer.

ISO 13616 IBAN mod-97 checksum validation, with optional BIC (ISO 9362) format check.

Human-readable relative time ('2 hours ago', 'in 3 days') between a datetime and a reference (default now).

Fact-check verdict written by Claude Haiku 5.5 (Anthropic) from real web sources: supported/contradicted/mixed/unverifiable, each source with its stance (supports/contradicts/neutral). Answer in a few seconds. Try GET /fact-check/sample. Independently monitored: lumierepaycheck.org/e?url=https://x402.agentindex.world/fact-check

Base mainnet network info in one call: chain ID, block height, and current gas price (wei and gwei).

Base mainnet chain ID (EIP-155) via eth_chainId - confirm which network you're actually talking to.

Base token safety check: Claude Haiku 5.5 (Anthropic) writes a rug pull / honeypot verdict (SAFE/CAUTION/RISKY/DANGER) from on-chain data, a tagline, a short explanation. Deterministic fallback if Claude is slow, honestly labeled. GET /token-card/sample.

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 {x} placeholders preserved per segment, order and count kept intact, source language auto-detected, automatic fallback across multiple models for uptime, providers that train on submitted prompts excluded. A single string also works. No acc

Total supply for an ERC20 (normalized by decimals()) or ERC721 (raw count, no decimals) contract on Base mainnet.

Slippage estimate, swap quote, and best DEX price on Base - compares Uniswap v2, Uniswap v3, and Aerodrome on-chain via Multicall3, returns amount received, chosen path, and price impact.

Next transaction nonce for any Base mainnet wallet via eth_getTransactionCount - how many transactions it has sent.

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.

ERC20 token balance for a wallet on Base mainnet - balanceOf() and decimals() batched into one Multicall3 round trip.

ERC1155 multi-token balance for a wallet and token id on Base mainnet via balanceOf(address,uint256).

Check whether a Base mainnet address is a contract via eth_getCode - returns bytecode size, zero for an externally-owned account.

Fetch a Base mainnet block header and transaction hashes by number, tag (latest/earliest/safe/finalized), or hash via eth_getBlockByNumber/eth_getBlockByHash.

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.

Gas estimate for a Base mainnet swap or any other call (to/from/value/data) via eth_estimateGas, without broadcasting a transaction.

Simulate a Base mainnet transaction before sending it - will it succeed, estimated gas, and the decoded revert reason if it would fail.

ERC20 Transfer event logs for one token over a Base mainnet block range (max 2,000 blocks) via eth_getLogs.

Contract introspection on Base mainnet - is it a contract, bytecode size, best-effort owner(), and whether it's a proxy.

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 sell reverts, that is a honeypot, reported with the exact decoded reason. Factual, never predictive.

Resolve a Basename, Base's native ENS-equivalent, to its wallet address via the L2 Basenames resolver.

Base transaction lookup by hash - sender, recipient, value, calldata, gas and block, live from Base mainnet via eth_getTransactionByHash.

The current pending Base mainnet block (mempool, not yet mined) - unconfirmed transactions via eth_getBlockByNumber('pending').

Generic read-only eth_call against any Base mainnet contract - pass raw calldata, get the raw return data back.

Voluntarily support AgentIndex with one cent of Base USDC. Returns payer identity, a thank-you acknowledgement and an x402 settlement receipt. Use this when an agent wants to sponsor open pay-per-call infrastructure.

Flatten a nested JSON document into single-level dotted-path keys.

Jev-powered research: routed search, cited answer, claims verified against sources. Ask a question, get a 5-8 sentence answer, each claim tagged to a numbered source, built from real page content - no invented facts. A fast paid LLM writes it, under 4.5s guaranteed; on a rare miss, a no-LLM extractive fallback (top sentences from the sources, picked by Jev) takes over instead, marked "synthesis":"

Jev-routed web search: each query goes to the best specialised source (code, facts, news, prices), results ranked by relevance. 28/30 test queries answered. Up to 10 results per query, each with title, URL, snippet, short extract and publish date. Up to 5 queries per call, merged and de-duplicated. No account, no API key. Try GET /search/sample. Part of the AgentIndex content kit (pdf, web-read, e

Convert text between utf-8, base64, hex, URL-percent-encoding and ascii representations.

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 metadata and a real token count. Text content itself is never generated or altered, only its structure is inferred. Try GET /pdf/sample. Part of the AgentIndex content kit (pdf, web-read, extract, summarize, detect-language) - see GET /capabi

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 same extraction /search uses on result pages, exposed standalone for a URL you already have. Try GET /web-read/sample. Part of the AgentIndex content kit (pdf, web-read, extract, summarize, detect-language) - see GET /capabilities.

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 /summarize/sample. Part of the AgentIndex content kit (pdf, web-read, extract, summarize, detect-language) - see GET /capabilities.

Convert an integer into English words.

Validate a JSON document against a JSON Schema.

Query a JSON document with a JSONPath expression.

Buy a 30-day verified agent listing for $0.01 USDC. AgentIndex audits reachability, x402 compatibility and discovery manifests, then publishes a machine-readable registry entry and score badge for buyer trust and SEO.

NFT metadata URI for an ERC721 token on Base mainnet via tokenURI - the on-chain pointer (IPFS, HTTP, or data URI), not a fetch of the document itself.

NFT holdings for a wallet in one Base ERC721 collection, owned token IDs via ERC721Enumerable (tokenOfOwnerByIndex) - up to 20 tokens, requires the collection to implement Enumerable.