Agent discovery

Nibgate can make paid content discoverable to AI agents without exposing protected content. Agents get structured metadata, verified source context, price information, and unlock routes.

Why agents need a discovery layer

Agents need to answer questions like:

• What content exists?
• Who published it?
• Is the source verified?
• What does it cost to unlock?
• What type of content is it?
• Has it been useful to other users or agents?
• Where can the agent unlock or cite it?

Agent-readable content cards

Relationship to agent registries

Agent identity and reputation standards focus on whether an agent can be identified, trusted, or validated. Nibgate focuses on the content side: verified sources, content quality, unlock events, and feedback tied to real interactions.

Discovery surfaces

Agents can discover content through Explore, public metadata APIs, search filters, tags, content type routes, creator profiles, and future machine-readable manifests.

Machine-readable discovery guide

A plain-language agent discovery guide is available at https://nibgate.xyz/discovery.md. It describes every Nibgate endpoint, the payment flow, and the rating flow — no HTML rendering needed, readable directly by any agent.

Public ledger

The ledger at https://nibgate.xyz/ledger (API: GET /api/hub/ledger) provides a live feed of all views, unlocks, payments, and ratings across sites. Agents can filter by ?domain= for per-site activity. Each entry includes timestamps, wallet addresses, and on-chain tx hashes where applicable.

Hub explore API

GET https://nibgate.xyz/api/hub/explore/content?type=article&sort=trending&limit=50
Accept: application/json

Returns content with pricing, access policy, creator domain, and reputation signals.

Creator manifests

Agents can also poll /nibgate.json directly from creator sites to discover content with full resource metadata including price, currency, recipient wallet, and access policy.

Purchasing content via x402

Once an agent discovers content, it can purchase and unlock it through the same x402 protocol used by browser wallets — no browser, HTML, or widget needed.

Headless purchase flow

import { GatewayClient } from '@circle-fin/x402-batching/client'
 
const agent = new GatewayClient({
  chain: 'arcTestnet',
  privateKey: '0x...',
  rpcUrl: 'https://rpc.testnet.arc.io'
})
 
const result = await agent.pay(
  'https://creator.example/api/nibgate/access?path=/writing/my-article',
  {
    headers: { 'x-nibgate-actor': 'agent' }
  }
)
// { data: { ok: true, unlockProof, payment }, formattedAmount: '0.01', transaction: '0x...' }

The GatewayClient.pay() method handles the full flow:

1. Makes the initial request
2. Receives HTTP 402 with PAYMENT-REQUIRED header
3. Signs an EIP-3009 TransferWithAuthorization using the agent’s private key
4. Retries with Payment-Signature header
5. Returns the unlocked content on success

Agent identification

Agents identify themselves via headers:

Agent wallet requirements

• USDC balance on Arc Testnet (chain ID 5042002)
• USDC deposited into Circle Gateway via agent.deposit('10')
• Private key accessible to the agent process

Agent-specific pricing

Creators set different prices for humans vs agents in the resource’s access policy:

const resource = {
  access: { humans: 'free', agents: 'paid' },  // agents pay, humans free
  price: '0.002',
}

Quality over raw indexing

Nibgate should prefer verified, useful, paid content over noisy indexing. Ranking can use verified interactions rather than only clicks or self-reported metadata.