Monetize WordPress content with x402 micropayments. Readers with a compatible x402 browser extension unlock posts instantly with a one-time USDC payment. Everyone else sees a teaser with an install prompt.
No accounts. No subscriptions. No payment forms. Just add a Content Gate block, set a price, and publish.
Download latest release → · Full documentation → · Get the browser extension →
Primer Pay is an implementation of the x402 protocol — the HTTP-native payment standard built on status code 402 "Payment Required". This plugin turns any WordPress post or page into a paywalled x402 resource:
- A visitor loads a paywalled post. WordPress serves the teaser + a small unlock container.
- JavaScript fires a fetch to the plugin's REST endpoint.
- If the visitor has a compatible x402 browser extension installed, it intercepts the 402 response, signs a USDC payment, and retries transparently.
- The plugin validates the signed payment via the Primer facilitator, sets an HMAC-signed access cookie, and returns the unlocked content.
- Subsequent visits within the session duration are served from the cookie — no re-payment on refresh.
Visitors without a compatible extension see a teaser and a prompt explaining how to access the content.
- Gutenberg Content Gate block — visual editor block that splits free teaser from paid content, with price, duration, and wallet settings in the block sidebar
- Classic editor support —
[primer_pay_x402]shortcode + sidebar meta box for sites not using Gutenberg - Per-post price override (defaults to your site-wide price)
- Per-post wallet override — route payments to a different wallet per post (multi-author support)
- Multi-network support: accept payments on Base (Ethereum L2) and/or SKALE Base (zero-gas EVM) — with configurable priority
- Theme-matching paywall banner — inherits your site's fonts, colors, and border radius via CSS custom properties
- Configurable access duration: 30 minutes to "never expires" — prevents double-charging on refresh
.well-known/x402discovery endpoint — JSON index of all paywalled content at/.well-known/x402, enabling AI agents and crawlers to discover purchasable content automatically- Works with any theme that renders
the_content()normally — no template modifications needed - Non-custodial: payments go directly from the reader's wallet to yours. The plugin never touches funds.
- WordPress 5.8+
- PHP 7.4+
- A wallet address that can receive USDC payments on Base or SKALE Base (e.g. from MetaMask, Coinbase Wallet, or the Primer Pay extension itself — the same address works on all supported networks)
- HTTPS recommended (cookies set with the
Secureflag on HTTPS; HTTP will still work for local dev)
- In your WordPress admin, go to Plugins → Add New
- Search for "Primer Pay"
- Click Install Now, then Activate
- Download the latest release: primer-pay.zip
- In your WordPress admin, go to Plugins → Add New → Upload Plugin
- Select the zip file and click Install Now
- Click Activate Plugin
- Download and extract the zip from GitHub releases
- Upload the
primer-pay/folder to/wp-content/plugins/on your site - Activate the plugin through Plugins → Installed Plugins
- Go to Settings → Primer Pay in your WordPress admin.
- Enter your wallet address — the address that should receive USDC payments.
- Leave Default Price at
0.01(or set whatever you like), pick an Access Duration, and choose which networks to accept (Base, SKALE Base, or both). Save. - Edit any post and add the Primer Pay Content Gate block where you want the teaser to end. All paywall settings (enable/disable, price, duration, wallet) are in the block's sidebar panel.
Block editor (Gutenberg): Add the "Primer Pay Content Gate" block. Everything above it is the free teaser; everything below is the paid content. Configure price, access duration, and wallet override in the block sidebar.
Classic editor: Add the [primer_pay_x402] shortcode anywhere in your post content:
This is the free preview everyone sees.
[primer_pay_x402]
This is the paid content only visitors who pay can read.
If you don't add a Content Gate block or shortcode, the plugin falls back to the post's excerpt as the teaser.
The plugin serves a machine-readable JSON index of all paywalled content at /.well-known/x402. AI agents, crawlers, and other x402-aware clients can discover purchasable content without browsing the site:
GET https://yoursite.com/.well-known/x402
Returns titles, URLs, prices, networks, and wallet addresses for all paywalled posts. Cached for 5 minutes.
Install a compatible x402 browser extension, fund it with USDC on Base and browse normally. Paywalled content unlocks automatically — no logins, no forms, no checkout flow.
A docker-compose.yml is not yet included but the plugin is tested against Local by Flywheel. Any WordPress environment with the requirements above should work.
Clone this repo, copy or symlink the primer-pay/ folder into your site's wp-content/plugins/ directory, then activate it from the admin. Edit and reload.
- HMAC-signed cookies: access cookies are HMAC-SHA256 signed with a site-specific secret stored in
wp_options. Forgery requires database access. - HttpOnly cookies: cookies cannot be read by JavaScript, preventing XSS exfiltration.
- Constant-time comparison:
hash_equals()is used for cookie verification to prevent timing attacks. - No secrets shipped in the plugin: the secret is generated fresh per install on activation.
- Non-custodial: the plugin never handles private keys. All signing happens in the reader's browser extension.
- Earnings dashboard and payment history export
- MCP server for AI agent integration (search, preview, and purchase content programmatically)
- WooCommerce integration for digital downloads
- SIWX (Sign-In With X) wallet identity for cross-post access
- REST API and media-file gating for headless WordPress and gated downloads
Issues and pull requests are welcome. This is early software; reports of real-world integration quirks, theme incompatibilities, and edge cases are especially appreciated.
For larger features or architectural changes, please open an issue first so we can discuss before you spend time on a PR.
GPL-2.0-or-later — matching WordPress core. You're free to use, modify, and redistribute under the terms of the GPL.
- Primer Pay browser extension — the reader-side component, by the same team
- Primer Systems documentation — full protocol and tooling docs
- x402 specification — the underlying payment protocol
- Primer x402 facilitator — settlement service used by this plugin (free, Base network)
Built by Primer Systems. Questions: dev@primer.systems.