the402 x402 endpoint directory

Check whether an IP is inside a CIDR network for $0.001 USDC. Call when you need this bounded result without an API ke

Classify an IP as private/loopback/global (no geolocation) for $0.001 USDC. Call when you need this bounded result wit

Convert #hex or rgb() colors to hex/rgb/hsl for $0.001 USDC. Call when you need this bounded result without an API key

Convert text to a URL-safe slug for $0.001 USDC. Call when you need this bounded result without an API key or subscrip

Validate and describe a five-field cron schedule for $0.001 USDC, including the next runs. Call when you need this bou

Test a regular expression and return matches, groups, and counts for $0.001 USDC. Call when you need this bounded resu

SHA-256 hash API for agents: hash text with SHA-256, SHA-1, or MD5 for $0.001 USDC and return a compact deterministic

Inspect URL reachability, status, latency, and key headers for $0.001 USDC. Call when you need a cheap uptime prefligh

Encode or decode Base64 safely for $0.001 USDC; bounded, deterministic, and keyless. Call when you need this bounded r

Convert Unix, ISO 8601, and human timestamps for $0.001 USDC with one normalized response. Call when you need this bou

Estimate GPT- and Claude-style token counts for a text payload for $0.001 USDC; deterministic and keyless. Call when y

JSON validation API for agents: validate, normalize, and pretty-print a bounded JSON payload for $0.001 USDC with stru

Turns text or a URL into a PNG or SVG QR code. Useful for an agent generating tickets, onboarding links, or receipts.

Returns daily European Central Bank exchange rates for major currency pairs. Useful for an agent that needs an officia

Search bounded English Wikipedia metadata for $0.001 USDC through the public Wikimedia API. Returns attributed page li

Caesar shift cipher. Handy for puzzle agents, CTF helpers, or reversible toy encoding—not for secrets. Returns shifted

Base Settlement Receipt Check: Base Settlement Receipt Check checks caller-supplied receipt chain, status, recipient,

EVM Event Log Shape Check: EVM Event Log Shape Check checks address, topics, and data shapes for a caller-supplied log

EVM Tx Envelope Check: EVM Tx Envelope Check checks required envelope fields for a declared transaction type from boun

Seeded Canary Sequence: Seeded Canary Sequence orders subjects reproducibly for a staged canary rollout from bounded c

Seeded Load Spread: Seeded Load Spread assigns jobs reproducibly across workers with near-even counts from bounded cal

Seeded Candidate Subset: Seeded Candidate Subset selects a reproducible candidate subset while preserving original ord

Seeded Time Slot Pick: Seeded Time Slot Pick selects a reproducible slot from caller-provided time labels from bounded

Seeded Window Pick: Seeded Window Pick selects a reproducible contiguous window from caller items from bounded caller-

Seeded Derangement: Seeded Derangement finds a reproducible permutation where no item keeps its position from bounded

Seeded Pairing: Seeded Pairing creates reproducible non-overlapping pairs and reports an optional bye from bounded cal

Seeded Sample With Replacement: Seeded Sample With Replacement samples caller items reproducibly with replacement from

Seeded Balanced Groups: Seeded Balanced Groups distributes items reproducibly across near-equal groups from bounded ca

Seeded Stratified Split: Seeded Stratified Split splits labeled items while preserving per-label proportions from boun

Seeded Weighted Partition: Seeded Weighted Partition assigns items to partitions using reproducible capacity weights f

Seeded Permutation Index: Seeded Permutation Index selects one reproducible permutation index within a caller count fr

Seeded Range Sequence: Seeded Range Sequence generates unique reproducible integers from a bounded range from bounded

Seeded Nonce Decimal: Seeded Nonce Decimal derives a reproducible non-security decimal nonce inside bounds from bounde

Seeded Passphrase Words: Seeded Passphrase Words selects reproducible words from a caller list for non-secret labels f

Seeded Color Hex: Seeded Color Hex selects a reproducible display color without claiming accessibility from bounded ca

Seeded Grid Point: Seeded Grid Point selects a reproducible integer coordinate inside rectangular bounds from bounded

Seeded Matrix Cell: Seeded Matrix Cell selects one reproducible row and column inside matrix bounds from bounded calle

Seeded Sample Indices: Seeded Sample Indices samples unique zero-based indices from a population size from bounded cal

Seeded Batch Order: Seeded Batch Order orders batch identifiers reproducibly for replayable processing from bounded ca

Seeded Queue Pick: Seeded Queue Pick selects one queue reproducibly from available queue names from bounded caller-sup

Compute confirmations remaining from head and inclusion block. Call when progress bars and readiness gates for deposit

Estimate seconds to target block from current height and block time. Call when scheduling waits or SLA checks for conf

Build CAIP-2 chain identifiers from namespace and reference. Call when emitting standard chain IDs for multi-chain age

Parse CAIP-2 chain identifiers into namespace and reference parts. Call when normalizing multi-chain IDs from agent co

Estimate gas cost in USD given used gas, price, and ETH/USD. Call when operator reports that need approximate dollar g

Compute total gas cost in ether from used gas and price wei. Call when budgeting ETH spend for a planned or observed t

Compute gas_used × gas_price as total gas cost in wei. Call when estimating tx cost from known used gas and price with

Detect the zero EVM address used as empty/burn/default sentinel. Call when validating recipients or detecting unset ad

Lowercase-normalize EVM address shape without EIP-55 checksum work. Call when deduping addresses from mixed-case sourc

Encode non-negative integers into 0x-hex strings. Call when building simple hex fields or debug payloads from decimal