> For the complete documentation index, see [llms.txt](https://quick-ai.gitbook.io/qai-x402-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://quick-ai.gitbook.io/qai-x402-docs/guides/x402-bazaar.md).

# x402 & Bazaar Integration

All Quick AI agent services use the same payment and discovery patterns. This page describes how clients and marketplaces interact with them.

## Payment rail

| Property         | Value                                                 |
| ---------------- | ----------------------------------------------------- |
| Network          | `eip155:8453` (Base mainnet)                          |
| Scheme           | `exact`                                               |
| Asset            | USDC `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`     |
| Facilitator      | Coinbase CDP (`@coinbase/x402`)                       |
| Protocol version | x402 v2 (`X402-Version: 2` response header via Caddy) |

## Request lifecycle

```
1. Client calls paid endpoint without payment
   → 402 Payment Required
   → Payment-Required header (base64 JSON with accepts[], Bazaar extensions)

2. Client builds payment proof (awal, x402 client SDK, or agent wallet)

3. Client retries same request with payment header
   → Facilitator verifies
   → Route handler executes
   → Facilitator settles USDC to PAY_TO_ADDRESS
   → Payment-Response header on success (where applicable)
```

## Pricing summary

| Service         | Route                         | Price                          |
| --------------- | ----------------------------- | ------------------------------ |
| Eagle Eye       | `POST /check`                 | $0.005                         |
| Eagle Eye       | `POST /check/profile`         | $0.006                         |
| Eagle Eye       | `POST /check/batch`           | $0.005 × addresses (max $0.50) |
| Quick Signal TA | `POST /signal`, `GET /signal` | $0.05                          |
| Quick ZK Auth   | `POST /prove`                 | $0.05                          |

`GET /health` and Quick ZK Auth `GET /proof/:job_id` are free.

## Bazaar discovery

Each paid route registers a **Bazaar discovery extension** at startup with:

* `method`: `POST` or `GET` (must be set at declaration time for validator acceptance)
* `bodyType`: `json` for POST body routes
* `input` / `inputSchema`: what the agent must send
* `output.example` / `output.schema`: what the agent receives

Services run **`validateBazaarAtStartup()`** before listening. Invalid schemas cause the process to exit.

### Indexing checklist

After deploy:

1. Confirm startup log: `Bazaar extension valid`
2. Unpaid curl returns **402** with `Payment-Required`
3. Run one paid call per route (Hermes / awal)
4. Validate on [agentic.market](https://agentic.market) or CDP discovery tools

## Client tools

### awal (CLI)

```bash
npx awal x402 pay https://{host}/{path} -X POST -d '{...json...}'
```

### Unpaid probe

```bash
curl -i -X POST https://{host}/{path} \
  -H "Content-Type: application/json" \
  -d '{...}'
```

Expect `HTTP/2 402` and a `Payment-Required` header.

## Required operator configuration

Every service requires:

| Variable             | Purpose                    |
| -------------------- | -------------------------- |
| `CDP_API_KEY_ID`     | Facilitator authentication |
| `CDP_API_KEY_SECRET` | Facilitator authentication |
| `PAY_TO_ADDRESS`     | USDC payee on Base         |

Eagle Eye additionally requires `SERVICE_PRIVATE_KEY` for audit signatures.

Quick ZK Auth additionally requires `REDIS_URL` for v1.0.1 features (proof store, payment binding, replay control).

## Error codes (common)

| HTTP | Meaning                                         |
| ---- | ----------------------------------------------- |
| 402  | Payment required or settlement failed           |
| 400  | Invalid request body or query                   |
| 429  | Quick ZK Auth replay (duplicate proof in scope) |
| 503  | Eagle Eye health before first OFAC snapshot     |
| 404  | Unknown path                                    |


---

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