listed
tool-call-guard · x402.agentindex.world
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. Advisory only: like any LLM-based judge it is sensitive to prompt injection in the request or tool call, so the calling agent must keep the final decision, not delegate it outright. Try GET /guard/sample.
https://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 manifest. Returns a 0-100 score, verdict and issues. Try GET /agent-health/sample.
https://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 spending. Try GET /can-pay/sample.
https://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.
https://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 /gas-price/sample.
https://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.
https://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.
https://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 account. Try GET /wallet-balance/sample.
https://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 Base x402 payment readiness. One signature instead of ten paid requests. Try GET /wallet-intelligence/sample.
https://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.
https://x402.agentindex.world/base/allowance
ERC20 spending allowance an owner has granted a spender on Base mainnet, via allowance(owner,spender).
https://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.
https://x402.agentindex.world/base/block-number
Latest Base mainnet block height via eth_blockNumber - the current chain tip.
https://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 sell reverts, that is a honeypot, reported with the exact decoded reason. Factual, never predictive.
https://x402.agentindex.world/base/chain-id
Base mainnet chain ID (EIP-155) via eth_chainId - confirm which network you're actually talking to.
https://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.
https://x402.agentindex.world/base/erc1155-balance
ERC1155 multi-token balance for a wallet and token id on Base mainnet via balanceOf(address,uint256).
https://x402.agentindex.world/base/erc20-balance
ERC20 token balance for a wallet on Base mainnet - balanceOf() and decimals() batched into one Multicall3 round trip.
https://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.
https://x402.agentindex.world/base/network-info
Base mainnet network info in one call: chain ID, block height, and current gas price (wei and gwei).
https://x402.agentindex.world/base/nonce
Next transaction nonce for any Base mainnet wallet via eth_getTransactionCount - how many transactions it has sent.
https://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, chosen path, and price impact.
https://x402.agentindex.world/base/simulate
Simulate a Base mainnet transaction before sending it - will it succeed, estimated gas, and the decoded revert reason if it would fail.
https://x402.agentindex.world/base/total-supply
Total supply for an ERC20 (normalized by decimals()) or ERC721 (raw count, no decimals) contract on Base mainnet.
https://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 and an alternate label. Powered by Jev, falling back to a Groq-hosted LLM if Jev is slow or unavailable - under 4.5s guaranteed. Try GET /classify/sample.
https://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 (Jev decision primitives), not generated text. Powered by Jev (TypeSafe System One). $0.001 per call, no OpenRouter or TypeSafe account needed. Try GET /decide/sample.
https://x402.agentindex.world/discover
Find MCP servers matching a need, ranked by semantic similarity over a curated snapshot of 10101 MCP servers. Returns name, endpoint, description, source registry and a 0-1 relevance per match. Paid POST: up to 25 matches. Try GET /discover/sample.
https://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).
https://x402.agentindex.world/encoding/transcode
Convert text between utf-8, base64, hex, URL-percent-encoding and ascii representations.
https://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 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.
https://x402.agentindex.world/fraction/simplify
Simplify a fraction to lowest terms and return its decimal value.
https://x402.agentindex.world/geo/bbox
Bounding box (min/max lat and lon) enclosing a list of points.
https://x402.agentindex.world/geo/bearing
Initial compass bearing (0-360 degrees, clockwise from true north) from point 1 to point 2.
https://x402.agentindex.world/geo/distance
Great-circle distance between two lat/lon points (haversine formula). Returns km, mi or nm.
https://x402.agentindex.world/geo/dms
Convert decimal degrees to degrees/minutes/seconds, or DMS back to decimal degrees.
https://x402.agentindex.world/geo/geohash
Encode a lat/lon point into a geohash string (precision 1-12 characters).
https://x402.agentindex.world/geo/midpoint
Geographic (great-circle) midpoint between two lat/lon points.
https://x402.agentindex.world/geo/point-in-polygon
Ray-casting point-in-polygon test (planar approximation - fine for city/region-scale polygons).
https://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. Advisory only: like any LLM-based judge it is sensitive to prompt injection in the request or tool call, so the calling agent must keep the final decision, not delegate it outright. Try GET /guard/sample.
https://x402.agentindex.world/hash/hash
Compute an MD5, SHA-1, SHA-256 or SHA-512 hex digest of text.
https://x402.agentindex.world/hash/hmac
Compute an HMAC (MD5, SHA-1, SHA-256 or SHA-512) of text with a given key.
https://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 automatic Groq-hosted LLM fallback if Jev is slow or unavailable - under 4.5s guaranteed. Try GET /intent/sample.
https://x402.agentindex.world/json/diff
Recursive diff between two JSON documents: added, removed and changed paths.
https://x402.agentindex.world/json/flatten
Flatten a nested JSON document into single-level dotted-path keys.
https://x402.agentindex.world/json/schema-infer
Infer a basic JSON Schema (types, object properties, array item type) from an example document.
https://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-hosted LLM fallback if Jev is slow or unavailable - under 4.5s guaranteed. Try GET /language/sample.
https://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 reliability. You sign a fixed price computed from your max_tokens; unused tokens are not refunded. 20s server-side timeout - never charged if it fires; set your client timeout to 30s. Try GET /llm/claude-sonnet/sample.
https://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 sign a fixed price computed from your max_tokens; unused tokens are not refunded. 20s server-side timeout - never charged if it fires; set your client timeout to 30s. Try GET /llm/gpt-mini/sample.
https://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 computed from your max_tokens; unused tokens are not refunded. 20s server-side timeout - never charged if it fires; set your client timeout to 30s. Try GET /llm/llama/sample.
https://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.
https://x402.agentindex.world/money/format
Format a numeric amount with thousands separators, a chosen decimal precision and a currency symbol.
https://x402.agentindex.world/number/ordinal
Convert an integer to its English ordinal form (1st, 2nd, 3rd, 4th, 11th, 21st...).
https://x402.agentindex.world/number/radix
Convert a number's string representation from one base (2-36) to another.
https://x402.agentindex.world/number/roman
Convert an integer (1-3999) to a Roman numeral, or a Roman numeral back to an integer.
https://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 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 /capabilities.
https://x402.agentindex.world/pii-check
PII detection: flag whether text contains personally identifiable information (name plus contact details, email, phone, address, government ID, financial account) with a confidence score. Powered by Jev, with an automatic Groq-hosted LLM fallback if Jev is slow or unavailable - under 4.5s guaranteed. Try GET /pii-check/sample.
https://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. Try GET /rank/sample.
https://x402.agentindex.world/regex/replace
Replace regular expression matches in text, with an optional max-replacement count.
https://x402.agentindex.world/regex/test
Test a regular expression against text; returns match status, capture groups and span.
https://x402.agentindex.world/research
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":"extractive". Try GET /research/sample.
https://x402.agentindex.world/search
Web search: search the web and get ranked results with page content. Up to 10 results with title, URL, snippet and publish date, plus clean full-page Markdown for the top 3 by default. Up to 5 queries per call, merged and de-duplicated. Each query is routed by Jev to the best specialised source (code, facts, news, prices, weather). No account, no API key. Try GET /search/sample. Part of the AgentIndex content kit (pdf, web-read, extract, summarize, detect-language) - see GET /capabilities.
https://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-hosted LLM fallback if Jev is slow or unavailable ("engine":"jev"|"fallback" in the response) - under 4.5s guaranteed. Try GET /sentiment/sample.
https://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 unavailable - under 4.5s guaranteed. Try GET /spam-check/sample.
https://x402.agentindex.world/stats/correlation
Pearson correlation coefficient between two equal-length numeric series.
https://x402.agentindex.world/stats/percentile
Nth percentile of a list of numbers (linear interpolation between closest ranks).
https://x402.agentindex.world/stats/regression
Ordinary least squares simple linear regression (y = slope*x + intercept) with R-squared.
https://x402.agentindex.world/stats/summary
Descriptive statistics for a list of numbers: count, mean, median, sample stdev/variance, min, max.
https://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 /summarize/sample. Part of the AgentIndex content kit (pdf, web-read, extract, summarize, detect-language) - see GET /capabilities.
https://x402.agentindex.world/text/case
Convert text between case styles: snake_case, camelCase, PascalCase, kebab-case, Title Case, CONSTANT_CASE.
https://x402.agentindex.world/text/diff
Unified line diff between two texts, plus an overall similarity ratio (0-1).
https://x402.agentindex.world/text/readability
Flesch Reading Ease and Flesch-Kincaid Grade Level scores for English text (standard public formulas, heuristic syllable counting).
https://x402.agentindex.world/text/slug
Slugify text: strip accents, lowercase, replace non-alphanumerics with a separator.
https://x402.agentindex.world/time/add
Add a fixed duration (days/hours/minutes/seconds) to an ISO 8601 datetime.
https://x402.agentindex.world/time/between
Duration between two ISO 8601 datetimes, as total seconds and a days/hours/minutes/seconds breakdown.
https://x402.agentindex.world/time/business-days
Count weekdays (Mon-Fri) between two dates, inclusive of both endpoints.
https://x402.agentindex.world/time/convert
Convert an ISO 8601 datetime from one IANA timezone to another (handles DST automatically).
https://x402.agentindex.world/time/format
Format an ISO 8601 datetime using a strftime pattern.
https://x402.agentindex.world/time/humanize
Human-readable relative time ('2 hours ago', 'in 3 days') between a datetime and a reference (default now).
https://x402.agentindex.world/time/iso-week
ISO 8601 week number, ISO year and ISO weekday (1=Monday) for a date.
https://x402.agentindex.world/time/parse
Parse a date/time string (ISO 8601 by default, or a given strptime format) into its components.
https://x402.agentindex.world/token-risk
Base token risk scan: on-chain rug check and honeypot-style flag detection for any ERC-20, no GoPlus, DexScreener or other vendor - real Base token safety. Reads bytecode for mint/blacklist/pause/tax powers, EIP-1967 proxy, renounced ownership, plus Uniswap v2/v3 and Aerodrome liquidity. A Jev avoid/caution/acceptable verdict leads the response, raw signals follow. Holder concentration included only when history fits 1-2 log queries. Try GET /token-risk/sample.
https://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, with an automatic Groq-hosted LLM fallback if Jev is slow or unavailable - under 4.5s guaranteed. Try GET /toxicity/sample.
https://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 {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 account, no API key. Try GET /translate/sample.
https://x402.agentindex.world/unit/convert
Convert a value between units of length, mass, volume or temperature (C/F/K).
https://x402.agentindex.world/v1/chat/completions
OpenAI-compatible chat completions (non-streaming) for any OpenRouter model - GET /v1/models lists them free, with pricing (upstream cost x 1.10). Pay only for what you use: sign a ceiling based on your max_tokens, settle for real usage x 1.10 (min $0.001) once the call completes. Try GET /v1/chat/completions/sample.
https://x402.agentindex.world/validate/ean
EAN-8 or EAN-13 barcode checksum validation (auto-detected by length).
https://x402.agentindex.world/validate/iban
ISO 13616 IBAN mod-97 checksum validation, with optional BIC (ISO 9362) format check.
https://x402.agentindex.world/validate/imei
IMEI (15-digit mobile device identifier) Luhn checksum validation.
https://x402.agentindex.world/validate/isbn
ISBN-10 or ISBN-13 checksum validation (auto-detected by length).
https://x402.agentindex.world/validate/isin
ISIN (ISO 6166 security identifier) Luhn checksum validation.
https://x402.agentindex.world/validate/luhn
Luhn (mod 10) checksum validation, as used by most payment card numbers.
https://x402.agentindex.world/validate/routing
US ABA bank routing number (9-digit) checksum validation.
https://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.
https://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.
https://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. Try GET /verify/sample.
https://x402.agentindex.world/web-read
Fetch a URL and read the web page as 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.
https://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 wallets, Payment-Signature, facilitators and settlement. Try GET /x402-echo/sample.
https://x402.agentindex.world/mcp/relationship-memory/
This listing is taken from the catalogues and the provider named above. The price is what that source advertised.
