the402 x402 endpoint directory

EVM Gas Cost Ceiling: EVM Gas Cost Ceiling calculates a worst-case native fee from gas limit and fee cap from bounded

EVM Gas Limit Headroom: EVM Gas Limit Headroom calculates gas-limit headroom above an estimated gas amount from bounde

EVM Priority Fee Ratio: EVM Priority Fee Ratio calculates the priority-fee share of the total fee cap from bounded cal

EVM Fee Cap Order Check: EVM Fee Cap Order Check checks that the priority fee cap does not exceed the total fee cap fr

EVM Eip1559 Fee Check: EVM Eip1559 Fee Check checks dynamic-fee caps and calculates the worst-case transaction fee fro

EVM Legacy Fee Check: EVM Legacy Fee Check checks gasPrice and gasLimit values for a legacy transaction budget from bo

EVM Tx Type Classify: EVM Tx Type Classify classifies legacy, access-list, dynamic-fee, and blob transaction type code

EVM Nonce Replace Check: EVM Nonce Replace Check checks whether a proposed nonce targets a caller-supplied pending non

EVM Nonce Gap Check: EVM Nonce Gap Check calculates the gap between pending and proposed transaction nonces from bound

EVM Chain Match Check: EVM Chain Match Check compares transaction and expected chain identifiers from bounded caller-s

EVM Address List Dedupe: EVM Address List Dedupe deduplicates EVM address strings case-insensitively while preserving

EVM Address Zero Check: EVM Address Zero Check detects the all-zero EVM address after shape normalization from bounded

Validate 0x + 64 hex transaction hash shape. Call when preflight before receipt lookup. Returns valid boolean as deter

Sum gas + bridge fee + slippage budget into total cost. Call when comparing bridge routes with known component costs.

Remaining unlock amount for linear vesting with optional cliff. Call when token unlock schedules for runway/treasury m

JSON Array Flatten One: JSON Array Flatten One flattens exactly one nesting level from a JSON array from bounded calle

Factorial (n≤20). Call for combinatorics demos and small counting problems with an explicit n cap. Returns n! for n up

Apply reversible ROT13 to Latin letters while preserving numbers, punctuation, spacing, and letter case for $0.001 USD

Turn mixed human or machine text into production-ready snake_case, kebab-case, camelCase, PascalCase, CONSTANT_CASE, t

Guess extension from MIME type. Call when you name agent-generated files from content-type. Returns ext, mime, known f

Guess MIME type from file extension. Call when you set Content-Type hints for agent uploads. Returns mime, ext, known

Parse IPv4 into octets. Call when you validate IP literals held by agents. Returns valid flag and octets for $0.001 US

Validate http(s) URL shape. Call when you preflight agent-held URLs before fetch/extract. Returns valid boolean for $0

XML-escape text for safe embedding. Call when you build XML fragments from agent strings. Returns escaped text for $0.

HTML-unescape entities in text. Call when you reverse entities from agent-held HTML snippets. Returns unescaped text f

Percent-encode text for query components. Call when you build safe query values for agent URLs. Returns encoded text f

Colour utilities: ?op=convert (default) turns any hex/rgb()/hsl()/CSS-name into hex, rgb, hsl, hsv, alpha, relative lu

Returns a crypto spot price as the median of three exchanges.

CoinStats current Fear & Greed Index — sentiment score from Extreme Fear (0) to Extreme Greed (100)

ETH balance of a Base mainnet address, incl. balance_usd.

Generate a secure random integer in a caller-supplied range for $0.001 USDC. Call when you need a CSPRNG draw for ids,

Pick random items without replacement for $0.001 USDC. Call when you need this bounded result without an API key or su

Estimate reading time from word count for $0.001 USDC. Call when you need this bounded result without an API key or su

Truncate text with ellipsis for $0.001 USDC. Call when you need this bounded result without an API key or subscription

Sort lines of text for $0.001 USDC. Call when you need this bounded result without an API key or subscription. Returns

URL-encode or decode text for $0.001 USDC. Call when you need this bounded result without an API key or subscription.

Extract email-like addresses from text for $0.001 USDC. Call when you need this bounded result without an API key or s

Extract HTTP/HTTPS URLs from text for $0.001 USDC. Call when you need this bounded result without an API key or subscr

Normalize whitespace in text for $0.001 USDC. Call when you need this bounded result without an API key or subscriptio

Normalized string similarity (Levenshtein) for $0.001 USDC. Call when you need this bounded result without an API key

Levenshtein edit distance and similarity for $0.001 USDC. Call when you need this bounded result without an API key or

ISBN-10/ISBN-13 checksum validation for $0.001 USDC. Call when you need this bounded result without an API key or subs

Luhn checksum validation for digit strings for $0.001 USDC. Call when you need this bounded result without an API key

Compute absolute and percent change for $0.001 USDC. Call when you need this bounded result without an API key or subs

Join a base URL with a relative path for $0.001 USDC. Call when you need this bounded result without an API key or sub

Parse human durations like 1h30m for $0.001 USDC. Call when you need this bounded result without an API key or subscri

Strip markdown to plain text for $0.001 USDC. Call when you need this bounded result without an API key or subscriptio

Count words, characters, lines and paragraphs for $0.001 USDC. Call when you need this bounded result without an API k

Compare two semantic versions for $0.001 USDC. Call when you need this bounded result without an API key or subscripti

Strip HTML tags to plain text for $0.001 USDC. Call when you need this bounded result without an API key or subscripti