x402-payment-test

Read a contract storage slot on Base mainnet via eth_getStorageAt - the raw 32-byte value, decoded as hex and unsigned integer, zero-filled if unset.

Transaction receipt via eth_getTransactionReceipt - status, gas used, and event logs for a mined Base mainnet transaction.

Is this Base contract an upgradeable proxy? Proxy contract detection for EIP-1967 (transparent/UUPS), beacon, or EIP-1822 patterns, returning the implementation address.

Smart contract event logs on Base mainnet (Base contract events) via eth_getLogs - filter by contract address and up to 4 topics, up to 2,000 blocks, raw logs with topics, data, block and tx hash.

Who owns this NFT? ERC721 owner lookup on Base mainnet via ownerOf(tokenId).

Test a regular expression against text; returns match status, capture groups and span.

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.

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 more in one endpoint). Price: from $0.001, computed from your max_tokens × model rate × 1.10 (you sign a ceiling; unused tokens are not refunded). 20s server-side timeout - never charged if it fires; set your client timeout to 30s. Try GET

Check whether a source supports, contradicts, or gives insufficient information about a claim - a typed verdict with a real probability, not generated text. Powered by Jev (TypeSafe System One). $0.001 per call, no OpenRouter or TypeSafe account needed. Try GET /verify/sample.

French SIRET (14-digit business establishment number) Luhn checksum validation. Note: the rare La Poste SIREN exception to the standard rule is not applied.

US ABA bank routing number (9-digit) checksum validation.

ISIN (ISO 6166 security identifier) Luhn checksum validation.

ISBN-10 or ISBN-13 checksum validation (auto-detected by length).

IMEI (15-digit mobile device identifier) Luhn checksum validation.

EAN-8 or EAN-13 barcode checksum validation (auto-detected by length).

Convert a value between units of length, mass, volume or temperature (C/F/K).

Parse a date/time string (ISO 8601 by default, or a given strptime format) into its components.

ISO 8601 week number, ISO year and ISO weekday (1=Monday) for a date.

Convert an ISO 8601 datetime from one IANA timezone to another (handles DST automatically).

Duration between two ISO 8601 datetimes, as total seconds and a days/hours/minutes/seconds breakdown.

Add a fixed duration (days/hours/minutes/seconds) to an ISO 8601 datetime.

Flesch Reading Ease and Flesch-Kincaid Grade Level scores for English text (standard public formulas, heuristic syllable counting).

Unified line diff between two texts, plus an overall similarity ratio (0-1).

Convert text between case styles: snake_case, camelCase, PascalCase, kebab-case, Title Case, CONSTANT_CASE.

Descriptive statistics for a list of numbers: count, mean, median, sample stdev/variance, min, max.

Ordinary least squares simple linear regression (y = slope*x + intercept) with R-squared.

Pearson correlation coefficient between two equal-length numeric series.

Nth percentile of a list of numbers (linear interpolation between closest ranks).

Replace regular expression matches in text, with an optional max-replacement count.

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 (TypeSafe System One). $0.001 per call, no OpenRouter or TypeSafe account needed. Try GET /rank/sample.

Convert a number's string representation from one base (2-36) to another.

Convert an integer to its English ordinal form (1st, 2nd, 3rd, 4th, 11th, 21st...).

Format a numeric amount with thousands separators, a chosen decimal precision and a currency symbol.

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.

Infer a basic JSON Schema (types, object properties, array item type) from an example document.

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 with an automatic 2nd-provider retry if the first is slow - never charged if both miss; set your client timeout to 30s. Try GET /llm/g

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. Powered by Jev (TypeSafe System One). $0.001 per call, no O

Ray-casting point-in-polygon test (planar approximation - fine for city/region-scale polygons).

Geographic (great-circle) midpoint between two lat/lon points.

Encode a lat/lon point into a geohash string (precision 1-12 characters).

Convert decimal degrees to degrees/minutes/seconds, or DMS back to decimal degrees.

Initial compass bearing (0-360 degrees, clockwise from true north) from point 1 to point 2.

Bounding box (min/max lat and lon) enclosing a list of points.

Simplify a fraction to lowest terms and return its decimal value.

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.

Slugify text: strip accents, lowercase, replace non-alphanumerics with a separator.

North American VIN check-digit validation (NHTSA standard, position 9) plus WMI manufacturer lookup for a small set of known codes.

Luhn (mod 10) checksum validation, as used by most payment card numbers.

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.

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.