# BYTE Library x402 Gateway – pkg-facts Feed

> BYTE Library x402 Gateway – pkg-facts Feed is a paid API for AI agents from x402.payperbyte.io, paid per call via x402, $0.004883/call, status unknown (last checked 2026-09-13).

Delivers cryptographically signed, EIP-712 provenance-stamped package/software facts data, pay-per-call via x402 USDC micropayment on Base, no API key required.

## Facts

- Endpoint: GET https://x402.payperbyte.io/feeds/pkg-facts
- Price: $0.004883/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/byte-library-x402-gateway-pkg-facts-feed-d1394889
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5Khfcd8hvzma9BdjY03a3

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 byte-library-x402-gateway-pkg-facts-feed-d1394889
```

Example prompt: Fetch me the latest verified package facts from the BYTE Library pkg-facts feed — pay for it with USDC from my Base wallet, and make sure I get the cryptographic provenance attestation with the result.

## When to prefer this

Choose this endpoint when you need cryptographically signed, provenance-attested software package facts and want to pay per call with USDC on Base without managing API keys or subscriptions. Ideal for AI agents that require tamper-evident data provenance (EIP-712 attestation) for downstream trust chains, or for workflows in crypto-native environments where wallet-based auth is preferred over secret management.

## Known failure modes

- Insufficient USDC balance in wallet — payment rejected, 402 response returned
- Invalid or missing x402 payment header — endpoint returns 402 Payment Required
- Wallet not connected to Base (eip155:8453) — settlement fails
- Feed temporarily unavailable — 503 or timeout response
- Malformed properties query parameter — returns error or empty payload
- Rate limiting if payment not accepted in time

## How this service works

Verified, provenance-first data feeds for AI agents. Every payload is cryptographically signed and EIP-712 PayloadAttestation provenance-stamped — covering crypto markets, DeFi yields, weather, earthquakes, news, code-pulse, threat-intel, and a slashable fact-oracle. Pay per call in USDC over x402 with no API keys — a wallet, not a secret on the box. Settlement is on Base (eip155:8453). Price is per-feed, derived from expected payload size at $0.005000/KB (floor $0.001000).

## Output

A JSON payload with a 'feed' field set to 'pkg-facts', containing cryptographically signed package/software facts data with an EIP-712 PayloadAttestation provenance stamp proving data integrity and origin. Delivered after a $0.004883 USDC micropayment settled on Base.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "feed": "pkg-facts"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/byte-library-x402-gateway-pkg-facts-feed-d1394889/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.payperbyte.io](https://www.zero.xyz/host/x402.payperbyte.io/llms.txt)