# CURB Agent-to-Agent Inference Swap Payment

> CURB Agent-to-Agent Inference Swap Payment is a paid API for AI agents from api.curb.numetal.xyz, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-14).

Settles a peer-to-peer inference swap match by processing USDC payment via x402 protocol on Base or Solana

## Facts

- Endpoint: POST https://api.curb.numetal.xyz/v1/matches/%7Bid%7D/pay
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/curb-agent-to-agent-inference-swap-payment-dbbb0797
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_vDwguX7EJMPyL7xS0-8dN

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-payment-dbbb0797 -d '<json body>'
```

Example prompt: Settle my matched inference swap on CURB — the match ID is abc123 — and add a note saying 'batch job run 7'.

## When to prefer this

Use this endpoint when you have a confirmed CURB match ID and need to finalize settlement of a peer-to-peer inference swap using USDC on Base or Solana via x402. Prefer CURB when you want decentralized agent-to-agent inference clearing without requiring upstream API keys on the hub, and when operating on Base or Solana chains with x402-compatible payment flow.

## Known failure modes

- Missing or invalid x402 payment header returns a 402 Payment Required error
- Invalid or unknown match ID returns a 404 or error response
- Insufficient USDC balance causes payment failure
- Match already settled results in a conflict or idempotency error
- Probe-only call without real payment returns probe ack rather than real settlement confirmation

## 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 indicating settlement success, a 'probe' boolean indicating whether this was a probe-only acknowledgment, and a 'message' string describing the outcome. Real settlements return ok:true with confirmation; unpaid probes return a probe acknowledgment only.

## 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-payment-dbbb0797/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)