# Agent Payment Guard — BCS Chains Lookup

> Agent Payment Guard — BCS Chains Lookup is a paid API for AI agents from base-agent-preflight.bytoken2023.workers.dev, paid per call via x402, $0.003011/call, status unknown (last checked 2026-10-20).

Retrieves the list of supported blockchain chains available through the BCS (Blockchain Security) upstream service for x402 agent payment firewall routing.

## Facts

- Endpoint: GET https://base-agent-preflight.bytoken2023.workers.dev/v1/x402/bcs/chains?utm_source=zero.xyz
- Price: $0.003011/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-payment-guard-bcs-chains-lookup-46d0ec2d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZwCPsgGyCVcbqqitpDrc5

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 agent-payment-guard-bcs-chains-lookup-46d0ec2d
```

Example prompt: Show me which blockchain chains are currently supported by the x402 agent payment firewall so I can configure my AI agent's payment mandate correctly.

## When to prefer this

Use this endpoint when an AI agent needs to discover which blockchain chains are available for routing x402 payments through the Agent Payment Guard system, particularly before configuring payment mandates, budgets, or risk scoring rules. Prefer this over generic chain-list APIs when you need the chain list scoped to what the BCS payment firewall actually supports.

## Known failure modes

- Payment not provided or invalid x402 payment header — returns 402 Payment Required
- Upstream blockchainsecurity-atlantis service unavailable — returns 5xx error
- Rate limit exceeded — returns 429 Too Many Requests
- Invalid or malformed request parameters — returns 400 Bad Request

## How this service works

Machine-payable service intelligence for discovering, verifying, and monitoring identity, risk, authorization, execution-preflight, and evidence APIs before autonomous agents spend.

## Output

Returns a JSON object with product identifier 'bcs-chains', upstream service name 'blockchainsecurity-atlantis', a request ID, and a data object containing the list or metadata of supported blockchain chains available through the BCS upstream service. Credit cost and remaining credit fields are also included in upstream headers.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "required": {
   "type": "string"
  },
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "product": "bcs-chains",
  "upstream_headers": {
   "request_id": "example-request-id",
   "credit_cost": null,
   "credit_remaining": null
  },
  "upstream_service": "blockchainsecurity-atlantis",
  "upstream_response": {
   "data": {},
   "meta": {
    "request_id": "example-request-id"
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-payment-guard-bcs-chains-lookup-46d0ec2d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from base-agent-preflight.bytoken2023.workers.dev](https://www.zero.xyz/host/base-agent-preflight.bytoken2023.workers.dev/llms.txt)