@dexterai/x402-core

Canonical types, formatters, and a search client for the Dexter x402 ecosystem, shared by MCP servers, the SDK, and the ChatGPT widget.

Requirements

• Node.js 18 or newer

Install

npm install @dexterai/x402-core

Examples

Search for a capability and format the result for an MCP consumer:

import {
  capabilitySearch,
  buildSearchResponse,
} from '@dexterai/x402-core';

const result = await capabilitySearch({ query: 'weather data API' });
const response = buildSearchResponse(result);

Inspect an endpoint's current access and pricing requirements without paying:

import { checkEndpointPricing } from '@dexterai/x402-core';

async function inspectEndpoint(endpointUrl) {
  return checkEndpointPricing({ url: endpointUrl, method: 'GET' });
}

Search and check utilities inspect, discover, and format information. They do not authorize or execute payment. checkEndpointPricing sends a live guarded HTTPS request, so a non-GET check may still have provider-side effects.

Exports

• Formats and types: formatResource, formatPrice, roundSimilarity, formatVolume, plus raw capability, formatted resource, search, pricing, verification, usage, gaming, and enrichment types.
• Capability search: capabilitySearch.
• Search response builders: buildSearchResponse and buildSearchErrorResponse.
• Endpoint pricing and challenge inspection: checkEndpointPricing, exactAtomicString, parsePaymentRequiredHeader, sellerAcceptSha256, CheckResult, and PaymentOption.
• Public URL guard: assertPublicExternalUrl, createPinnedLookup, fetchPublicExternalUrl, isPublicIpAddress, parseExternalHttpUrl, and UnsafeExternalUrlError.
• Bazaar schema extraction: extractBazaarSchema and BazaarSchema.
• Schema resolution: resolveInputSchema, resolveOutputSchema, and their input, output, and source types.

Project

• Repository
• Homepage
• License: MIT