# Tarnak x402 Toolkit — Service Discovery API

> Tarnak x402 Toolkit — Service Discovery API is a paid API for AI agents from api.capousd-student-tools.me, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-31).

Lists available pay-per-call x402 API services on the Tarnak platform, filterable by category and price

## Facts

- Endpoint: GET https://api.capousd-student-tools.me/v1/services?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tarnak-x402-toolkit-service-discovery-api-81d63de0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XXAwDKp9C6i9S8SOxcsCw

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability tarnak-x402-toolkit-service-discovery-api-81d63de0
```

Example prompt: Show me all the available Tarnak x402 services in the 'data' category that cost less than $0.01 per call — I want to find a keyless API for token risk analysis.

## When to prefer this

Use this endpoint when an AI agent needs to dynamically discover which Tarnak x402 API tools are available before calling one — especially useful for browsing by category (compute, storage, data) or filtering by max price. Prefer this over hardcoding individual endpoint URLs when building flexible agent pipelines that adapt to new services as they are added.

## Known failure modes

- No services match filter criteria — returns empty services array with count 0
- Invalid category string returns empty result set
- max_price too low to match any services — returns empty list
- limit out of range (below 1 or above 100) may return validation error
- Service unavailable or host unreachable returns network error

## How this service works

Keyless pay-per-call APIs for AI agents on Base: token risk verdict, rug/honeypot report, gas estimate, URL-to-markdown and more. x402 v2, USDC, no API key or signup. 10 free verdicts per IP per day.

## Output

Returns a JSON object with a count of matching services and an array of service descriptors, each including the service URL, slug identifier, network (e.g. 'base'), category label, and price in USD per call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "limit": {
       "type": "integer",
       "default": 20,
       "maximum": 100,
       "minimum": 1
      },
      "category": {
       "type": "string",
       "description": "e.g. compute, storage, data."
      },
      "max_price": {
       "type": "number",
       "description": "Max USD price per call."
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 1,
  "services": [
   {
    "url": "https://x-pay.example",
    "slug": "x-pay",
    "network": "base",
    "category": "compute",
    "price_usd": 0.002
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tarnak-x402-toolkit-service-discovery-api-81d63de0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.capousd-student-tools.me](https://www.zero.xyz/host/api.capousd-student-tools.me/llms.txt)