Discovery API

The Discovery API returns x402-compatible services that accept USDC, across 15+ blockchain networks, from one public endpoint. It powers the catalog UI and is open for any client, wallet, or agent to query directly. The catalog is curated and continuously sanctions-screened on the seller side, and every listing carries structured payment requirements and JSON Schema, so any wallet can pay for and call a service on top of x402. See the marketplace overview for the full rationale.

Endpoint

GET https://api.circle.com/v2/x402/discovery/resources

This endpoint is public. It needs no authentication, no API key, and no Circle account. Responses support gzip compression, so pass --compressed when you call it with curl.

Query parameters

All parameters are optional. Combine them to narrow the catalog to exactly the services your agent can use.

Parameter	Type	Description
`query`	string	Fuzzy search across resource URLs, providers, descriptions, and tags.
`type`	string	Protocol type: `http` or `mcp`.
`category`	string	Service category, one of the six values in Categories (for example, `FINANCIAL_ANALYSIS`).
`network`	string	CAIP-2 identifier (for example, `eip155:8453`) or a legacy SDK name (for example, `base`, `base-sepolia`). Only EVM chains have legacy aliases; Solana must use its full CAIP-2 identifier.
`asset`	string	Payment token contract address.
`scheme`	string	Payment scheme (for example, `exact`).
`payTo`	string	Merchant (seller) wallet address.
`maxUsdPrice`	number	Maximum price per request in USD (for example, `0.01`).
`supportsVanillax402`	boolean	`true` returns endpoints that support vanilla x402 (onchain payments).
`supportsCircleGateway`	boolean	`true` returns endpoints that support Circle Gateway (offchain, batched payments).
`siwx`	boolean	`true` returns only SIWX (Sign-In With X, browser-auth) endpoints; `false` excludes them; omit to return all. Use `false` for CLI or automation.
`fields`	string	Comma-separated list of fields to include in each item.
`limit`	integer	Number of items to return. Default `50`, maximum `200`.
`offset`	integer	Number of items to skip, for pagination. Default `0`.

Response

The response follows the x402 Bazaar discovery schema, the discovery format standardized as an x402 v2 extension. Clients built against another Bazaar-compatible catalog can parse this one unchanged. A successful call returns a JSON object with three top-level fields:

x402Version: the x402 protocol version the response follows.
items: an array of service listings (described below).
pagination: the limit, offset, and total count for the query.

{
  "x402Version": 2,
  "items": [
    {
      "resource": "https://api.aisa.one/apis/v2/coingecko/simple/price",
      "type": "http",
      "x402Version": 2,
      "lastUpdated": "2026-06-25T16:40:14.015Z",
      "accepts": [
        {
          "scheme": "exact",
          "network": "eip155:8453",
          "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
          "amount": "10000",
          "payTo": "0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed",
          "extra": { "name": "USD Coin", "version": "2" }
        }
      ],
      "metadata": {
        "provider": {
          "name": "AIsa API",
          "description": "cryptocurrency market data prices",
          "category": "FINANCIAL_ANALYSIS",
          "tags": ["x402", "crypto", "market-data"],
          "website": "https://aisa.one",
          "docsUrl": "https://aisa.one/docs/api-reference",
          "openApiUrl": "https://aisa.one/openapi.yaml"
        },
        "path": "/apis/v2/coingecko/simple/price",
        "method": "GET",
        "description": "Get cryptocurrency prices in multiple currencies",
        "mimeType": "application/json",
        "input": {
          "type": "object",
          "properties": { "ids": { "type": "string" } }
        },
        "output": { "type": "object" },
        "siwx": false,
        "supportsVanillax402": true,
        "supportsCircleGateway": true
      }
    }
  ],
  "pagination": { "limit": 50, "offset": 0, "total": 636 }
}

Each item in items describes one service:

accepts[] lists the payment requirements the service accepts. Each entry carries the network (CAIP-2), the asset (token contract address), the scheme (for example, exact), the amount, and the payTo seller wallet. amount is in atomic units: USDC has 6 decimals, so 10000 equals 0.01 USDC. v2 uses amount (v1 used maxAmountRequired).
metadata.provider describes the seller: name, description, category, tags, website, and documentation URLs.
metadata also carries the request path and method, an input and output JSON Schema, and three capability flags: supportsVanillax402 (accepts onchain x402 payments), supportsCircleGateway (accepts Gateway offchain batched payments), and siwx (requires browser-based Sign-In With X).

Examples

curl --compressed \
  "https://api.circle.com/v2/x402/discovery/resources?query=weather"

curl --compressed \
  "https://api.circle.com/v2/x402/discovery/resources?network=eip155:8453&maxUsdPrice=0.01&siwx=false"

curl --compressed \
  "https://api.circle.com/v2/x402/discovery/resources?supportsCircleGateway=true&network=eip155:8453"

circle services search "weather"

Category	Description
`SOCIAL_INTELLIGENCE`	Social platform data and audience or sentiment signals.
`FINANCIAL_ANALYSIS`	Market data, prices, and financial analytics.
`WEB_SEARCH_RESEARCH`	Web search, scraping, and research retrieval.
`PREDICTION_MARKETS`	Odds, forecasts, and prediction-market data.
`CREATIVE`	Media generation such as images, audio, and text.
`INFRASTRUCTURE`	Developer tooling and infrastructure utilities.

Paying for a service

Discovery tells you what each service accepts. To actually pay, use one of two rails:

Vanilla x402: a signed onchain USDC transfer that any USDC wallet, including a centralized custodial one, can produce.
Circle Gateway: offchain, batched settlement for gasless, sub-cent payments.

Each listing’s accepts[] and its supportsVanillax402 and supportsCircleGateway flags tell you which rails it takes. To pay from Circle CLI, see Pay for a service. For the concepts and buyer integration, see Agent nanopayments.

To find services payable on a specific blockchain, filter with the structured network parameter, not the query text field. query matches free text (URLs, providers, descriptions, tags), so it does not reliably match a chain.

Circle CLI

Agent wallets

Agent marketplace

Agent nanopayments

Endpoint

Query parameters

Response

Examples

Categories

Paying for a service

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​Query parameters

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​Related

Endpoint

Query parameters

Response

Examples

Categories

Paying for a service

Related