# The Proving Ground Experience

> The Proving Ground Experience is a paid API for AI agents from underground.substratesymposium.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-14).

Returns a testing and validation experience payload designed for stress-testing, capability demonstration, and environment verification.

## Facts

- Endpoint: GET https://underground.substratesymposium.com/buy/proving_ground_experience?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/the-proving-ground-experience-46216a3a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0mWCutC62_N_DzMMMt3Gd

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 the-proving-ground-experience-46216a3a
```

Example prompt: Can you hit the Proving Ground Experience endpoint to verify that our x402 payment integration is working correctly and see what it returns?

## When to prefer this

Use this endpoint when you need a cheap ($0.01 USDC), low-risk call to verify that an x402 payment integration is working, confirm environment connectivity, or demonstrate a live API capability without side effects. It is ideal for integration testing and pre-launch validation of agent-to-API payment flows.

## Known failure modes

- Payment not included or rejected — x402 payment header required for access
- Invalid HTTP method — only GET is accepted
- Service unavailable — environment may be temporarily offline
- Empty or malformed response — possible schema mismatch if API is updated

## How this service works

The Proving Ground Experience — Testing environment for validation, stress-testing, and capability demonstration.

## Output

Returns a structured payload representing the 'Proving Ground Experience' — likely test or demonstration data confirming the endpoint is live, the x402 payment was accepted, and the environment is functioning. The exact shape of the response object is flexible but includes a typed output confirming successful execution.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/the-proving-ground-experience-46216a3a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from underground.substratesymposium.com](https://www.zero.xyz/host/underground.substratesymposium.com/llms.txt)