# CURB Agent-to-Agent Inference Swap Clearinghouse

> CURB Agent-to-Agent Inference Swap Clearinghouse is a paid API for AI agents from api.curb.numetal.xyz, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-15).

Clears peer-to-peer inference swap transactions between agents, accepting USDC payment via x402 on Base and Solana without requiring upstream API keys on the hub.

## Facts

- Endpoint: POST https://api.curb.numetal.xyz/v1/pay
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/curb-agent-to-agent-inference-swap-clearinghouse-fd3c4e0f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_WTaczCZZF-aoqgy2ndZ7Y

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 curb-agent-to-agent-inference-swap-clearinghouse-fd3c4e0f -d '<json body>'
```

Example prompt: I want to clear an inference swap between my agent and a peer through CURB — go ahead and submit the swap request and settle it with USDC on Base via x402.

## When to prefer this

Choose this endpoint when you need to clear or settle a peer-to-peer AI inference swap between agents without holding upstream provider API keys on a central hub. Prefer CURB when both parties are already matched and you need to finalize the swap with USDC payment on Base or Solana via x402. This is the right choice for decentralized agent compute marketplaces where no intermediary key management is desired.

## Known failure modes

- Payment not included — returns 402 Payment Required with x402 challenge
- Invalid or expired payment — payment header rejected
- Swap match ID not found — 404 on /v1/matches/{id}/pay
- Unsupported chain — only Base and Solana USDC accepted
- Malformed request body — schema validation error
- Hub temporarily unavailable — 503 or timeout

## How this service works

CURB clears peer-to-peer inference swaps. We accept payment in USDC on x402 on both Base and Solana, and via pay.sh on Solana. No upstream keys on the hub.

## Output

Returns a JSON object with an 'ok' boolean and a 'probe' flag indicating whether the response is a probe acknowledgment or a live settlement confirmation. On probe requests, returns a message directing real swaps to POST /v1/matches/{id}/pay. On settled swaps, confirms clearance of the peer-to-peer inference transaction.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "note": {
   "type": "string",
   "description": "Optional; ignored on unpaid probe."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "probe": true,
  "message": "Probe ack only — settle real swaps via POST /v1/matches/{id}/pay"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/curb-agent-to-agent-inference-swap-clearinghouse-fd3c4e0f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.curb.numetal.xyz](https://www.zero.xyz/host/api.curb.numetal.xyz/llms.txt)