primersystems

Primer Pay lets you put any post or page behind a micropayment wall using the x402 protocol. Visitors with the Primer Pay browser extension pay seamlessly and see your content instantly. No user accounts, no subscriptions, no payment forms.
How it works:
<ol>
<li>You enter your wallet address in Settings > Primer Pay.</li>
<li>You check “Enable x402 Paywall” on any post and set a price (e.g., $0.01 USDC).</li>
<li>Visitors with the Primer Pay Chrome extension pay automatically and see your content.</li>
<li>Visitors without the extension see a teaser and a prompt to install Primer Pay.</li>
<li>Payments settle on Base (Ethereum L2) via USDC — low fees, instant finality.</li>
</ol>
Features:
<ul>
<li>Gutenberg Content Gate block — visual divider between free teaser and paid content with inline settings</li>
<li>Classic editor support — <code>[primer_pay_x402]</code> shortcode plus sidebar meta box</li>
<li>Per-post price override (defaults to your site-wide price)</li>
<li>Per-post wallet override — route payments to a different wallet per post (multi-author support)</li>
<li>Multi-network: accept payments on Base, SKALE Base, or both — with configurable priority</li>
<li>Theme-matching paywall banner — inherits your site’s fonts, colors, and border radius</li>
<li>Configurable access duration: 30 minutes to “never expires”</li>
<li><code>.well-known/x402</code> discovery endpoint — JSON index for AI agents and crawlers to find purchasable content</li>
<li>Works with any theme that renders the_content() normally</li>
<li>No user accounts or login required</li>
<li>Non-custodial — payments go directly to your wallet</li>
</ul>
Requirements:
<ul>
<li>A wallet address on Base or SKALE Base (e.g., from MetaMask, Coinbase Wallet, or Primer Pay itself — same address works on all supported networks)</li>
<li>HTTPS recommended (cookies are marked Secure on HTTPS; HTTP still works for local dev)</li>
</ul>
<h3>External services</h3>
This plugin relies on the Primer x402 facilitator service to verify and settle payments. When a visitor attempts to pay for content, the plugin sends the signed payment authorization to the facilitator, which validates the signature and executes the on-chain USDC transfer on the Base network.
<ul>
<li>Service: Primer x402 Facilitator</li>
<li>Endpoint: https://x402.primer.systems/settle</li>
<li>When: Whenever a visitor submits a valid X-PAYMENT header to the plugin’s unlock endpoint</li>
<li>Data sent: The base64-encoded signed payment authorization (EIP-712 typed data) from the visitor, plus the payment requirements (amount, asset address, recipient wallet address, network). No personally identifiable information about the visitor is sent — the only identifier is the wallet address they signed with.</li>
<li>Terms of service: https://primer.systems</li>
<li>Privacy policy: https://primer.systems</li>
</ul>
This is the standard x402 protocol flow. If you prefer to run your own facilitator, you can configure a custom facilitator URL in the plugin settings.

Primer Pay

Monetize your WordPress content with x402 micropayments. No accounts, no subscriptions — just instant pay-per-view with USDC.

nanotrans01

NanoTrans Agent Paywall is an agent-native paywall plugin that enables AI agents to automatically discover and purchase WordPress content using the x402 payment protocol with USDC stablecoin on the Base Network (Ethereum L2).
Key Features:
<ul>
<li>Dual Access – Humans pay via browser wallet (MetaMask); AI agents pay automatically via x402 protocol</li>
<li>x402 Protocol – Industry-standard HTTP 402 payment flow with EIP-712 signatures</li>
<li>USDC Payments – Stablecoin payments on Base Network (low gas fees, fast settlement)</li>
<li>Agent Discovery – <code>/.well-known/x402</code> endpoint for automatic content discovery</li>
<li>Gutenberg Block – Visual paywall block editor with price configuration</li>
<li>Batch Payments – Purchase up to 20 articles in a single transaction</li>
<li>Admin Dashboard – Revenue tracking, anomaly detection, emergency controls</li>
<li>MCP Server – Compatible with Claude, Cursor, and other MCP clients</li>
<li>Real-time Notifications – SSE-based payment alerts</li>
<li>Permanent Access – One-time payment grants permanent access via signed wallet cookie</li>
</ul>
How It Works:
<ol>
<li>Publisher sets content prices using the Gutenberg paywall block</li>
<li>AI agent requests content and receives HTTP 402 with payment requirements</li>
<li>Agent signs USDC payment via EIP-712</li>
<li>x402 Facilitator verifies payment on-chain</li>
<li>Content is delivered as structured JSON</li>
</ol>
For Content Publishers:
<ul>
<li>Set per-article prices in USDC</li>
<li>Dynamic pricing (agent vs human, time-based)</li>
<li>Revenue dashboard with real-time analytics</li>
<li>Automatic fund distribution via Splitter contracts</li>
</ul>
For AI Agent Developers:
<ul>
<li>MCP server for Claude/Cursor integration</li>
<li>OpenClaw SKILL.md for agent skill registration</li>
<li>Structured JSON API responses</li>
<li>Spending limits and audit logging</li>
</ul>
<h3>External services</h3>
This plugin relies on the following third-party services to process x402 micropayments. Payments cannot be verified or settled without them. All connections are opt-in: no outbound network call is made until the site administrator explicitly enables the Facilitator Proxy connection in Settings > NanoTrans and saves the settings.
1. NanoTrans Facilitator Proxy (Cloudflare Worker)
<ul>
<li>What it is: A Cloudflare Worker operated by NanoTrans that brokers authenticated requests to the Coinbase CDP x402 Facilitator. It signs requests with CDP credentials on your behalf so site owners do not need to manage CDP API keys.</li>
<li>What data is sent, and when: Only after the site administrator opts in (checks “Enable Facilitator Proxy connection” in Settings > NanoTrans and saves the settings). On the first save after opt-in, the plugin sends the site URL to register the site and receive an API key. During each payment attempt, it forwards x402 payment headers (EIP-712 signed USDC transfer authorization, payer wallet address, transaction hash, amount, recipient address) to verify and settle the payment.</li>
<li>Default endpoint: https://nanotrans-facilitator-proxy.celee.workers.dev/ (configurable via the NANOTRANS_FACILITATOR_URL constant in wp-config.php).</li>
<li>Terms of service: https://www.cloudflare.com/website-terms/</li>
<li>Privacy policy: https://www.cloudflare.com/privacypolicy/</li>
</ul>
2. Coinbase Developer Platform (CDP) x402 Facilitator
<ul>
<li>What it is: Coinbase’s official x402 Facilitator service that verifies EIP-712 USDC transfer authorizations and submits settled transfers on the Base Network.</li>
<li>What data is sent, and when: Only during a payment attempt after Facilitator Proxy opt-in. The Cloudflare Worker forwards the signed USDC transfer authorization and payment requirements (payer address, receiver address, USDC amount, network ID, nonce, signature) so CDP can validate and broadcast the on-chain settlement.</li>
<li>Endpoint: https://api.cdp.coinbase.com/platform/v2/x402</li>
<li>Terms of service: https://www.coinbase.com/legal/cloud/terms-of-service</li>
<li>Privacy policy: https://www.coinbase.com/legal/privacy</li>
</ul>
3. Base Network JSON-RPC (public endpoint)
<ul>
<li>What it is: A public JSON-RPC endpoint for Base Mainnet and Base Sepolia used to read on-chain transaction receipts and verify that a USDC transfer has been confirmed.</li>
<li>What data is sent, and when: Only after a payment attempt. The plugin issues read-only RPC calls (eth_getTransactionReceipt, eth_call) with the submitted transaction hash and USDC contract address.</li>
<li>Endpoint: https://mainnet.base.org (Base Mainnet) and https://sepolia.base.org (Base Sepolia).</li>
<li>Terms of service: https://www.base.org/terms-of-service</li>
<li>Privacy policy: https://www.coinbase.com/legal/privacy</li>
</ul>
4. Bundled ethers.js provider URLs (not called by this plugin)
The ethers.js library bundled at assets/js/ethers.umd.min.js is the official upstream UMD build from https://github.com/ethers-io/ethers.js (version 6.16.0, MIT licensed). That bundle contains hard-coded provider URLs for common block explorers (listed below) as part of its default provider list.
<ul>
<li>This plugin does NOT call any of these URLs. It only uses ethers.js for EIP-712 signing and USDC contract read/write through the user’s browser wallet (MetaMask or compatible) and the configured Base Network RPC endpoint listed above.</li>
<li>No Etherscan/Arbiscan/Basescan API keys are configured, requested, or stored by this plugin.</li>
<li>Domains present in the ethers.js bundle for reference (NOT contacted by this plugin):
<ul>
<li>https://api.etherscan.io</li>
<li>https://api-goerli.etherscan.io</li>
<li>https://api-sepolia.etherscan.io</li>
<li>https://api-holesky.etherscan.io</li>
<li>https://api.arbiscan.io</li>
<li>https://api-goerli.arbiscan.io</li>
<li>https://api.basescan.org</li>
</ul>
</li>
<li>If a user integrates a custom ethers.js provider pointing to one of these endpoints, the operator of that endpoint is responsible for its own terms and privacy policy. For the default ethers.js usage in this plugin, no connection is made to any of them.</li>
<li>ethers.js upstream license: https://github.com/ethers-io/ethers.js/blob/main/LICENSE.md</li>
</ul>
No personal data (email, real name, IP logs) is sent to any of these services. Wallet addresses are pseudonymous blockchain identifiers required for USDC transfer settlement.
<h3>Privacy Policy</h3>
NanoTrans Agent Paywall processes the following data:
<ul>
<li>Wallet addresses: Stored in the transactions table for payment verification and receipt lookup. Wallet addresses are pseudonymous blockchain identifiers, not directly linked to personal identity.</li>
<li>User-Agent strings: Stored for request routing (human vs agent detection). Retained with transaction records.</li>
<li>IP addresses: Used for rate limiting only (via WordPress transients). Not permanently stored.</li>
<li>Wallet cookies: After a successful payment, an HMAC-signed cookie is set to grant permanent access to purchased content. The cookie contains a wallet address hash and a timestamp; no personal data is stored.</li>
</ul>
This plugin does not use third-party tracking services and does not collect email addresses or personal information.
For GDPR compliance, transaction records containing wallet addresses can be exported or deleted via the WordPress admin dashboard.

NanoTrans Agent Paywall

Agent-native paywall for WordPress. AI agents auto-pay for content via x402 (USDC on Base). Dual access for humans and agents.

Primer Pay vs NanoTrans Agent Paywall