Monetize
optional pay-per-read.

01Turning it on

CryptoMeter → Monetize: "Optional: let x402-capable AI agents pay per article in USDC, straight to your own wallet. Few agents pay today — treat it as an extra, not a revenue plan." Everything else in CryptoMeter works without it.

1. Switch Pay-per-read for AI agents on.
2. Enter your wallet under Payments and save. Until a valid wallet is saved, bots set to Charge are let through and counted as unpaid demand.
3. Choose which bots pay: on Bots & rules set an intent or a bot to Charge, or apply the preset Charge training and agents.
4. Stay in Test mode and use the Simulator first.

Switching Monetize off makes Charge behave like Allow again (logged as "Allowed"). Your wallet, prices and ledger are kept.

02Payments

03Pricing and per-post prices

Price calculation order

1. Per-post setting (editor): Read for free → 0; Blocked → 403; custom price → used as-is.
2. Category price: the highest CryptoMeter price among the post's categories.
3. Otherwise the site model (flat, or words ÷ 1,000 × price per 1,000 words).
4. Fresh premium or archive price (only one).
5. Training multiplier for AI training bots.
6. Minimum / maximum.
7. The cryptometer_price filter has the final say.

Per post and per category

• Editor box "CryptoMeter · AI access" (sidebar of metered post types), "AI bots reading this post": Pay site price (default), Pay a custom price (Price per read (USDC)), Read for free, Blocked. Blocked works with or without Monetize: AI bots get HTTP 403 for that post; humans and search engines are unaffected. The box shows the current price and, once there are payments, "Earned $X from N paid AI reads".
• Posts list: an "AI price" column (a price, Free or Blocked).
• Posts → Categories: field AI price per read (USDC) overrides the site price for posts in that category. Only the standard Categories taxonomy has it.

04The HTTP 402 flow

For developers and the curious. You do not need this to use the plugin.

1. Challenge. A bot set to Charge requests a metered post and gets HTTP 402 Payment Required with a PAYMENT-REQUIRED header (x402 v2, base64 JSON: resource plus one accepts entry per active network with scheme: "exact", CAIP-2 network, amount in atomic units, USDC contract, payTo, maxTimeoutSeconds, token name/version), a JSON body (v1 shape when v1 is accepted) with a cryptometer object (title, teaser, price, networks, message), and Link: </llms.txt>; rel="describedby". Verified on a test install: GPTBot with the Charge preset got 402, x-cryptometer: challenge, amount 10000 (0.01 USDC) on base-sepolia.
2. Pay. The agent signs a USDC TransferWithAuthorization (EIP-3009) for exactly that amount to your address and retries with PAYMENT-SIGNATURE (v2) or X-PAYMENT (v1).
3. Check and settle. CryptoMeter checks locally (decoding, version, network, exact amount, token, recipient, validity window, unused nonce), throttles failed attempts (10 per IP per minute), calls the facilitator's /verify, reserves the nonce (replay protection) and calls /settle (one retry on "pending").
4. Deliver. HTTP 200 with PAYMENT-RESPONSE (v1: X-PAYMENT-RESPONSE) and the article as HTML, Markdown or JSON (see What paying agents receive). With an access window: X-CryptoMeter-Access (access pass) and X-CryptoMeter-Access-Expires.

Every non-search response CryptoMeter changes carries Cache-Control: no-store, private, max-age=0, Vary: User-Agent, Accept, PAYMENT-SIGNATURE, X-PAYMENT, the X-CryptoMeter decision header and the DONOTCACHEPAGE constant.

Back doors. With Monetize set up and "Show bots set to Charge only excerpts in RSS feeds and the REST API" on, charged bots see excerpts only in feeds, archive/home/search pages and /wp-json/wp/v2/… for metered post types.

05Networks and facilitators

Facilitators are independent third parties with their own terms, availability and possible fees. CryptoMeter does not operate one and takes no fee. Trust your facilitator: CryptoMeter checks amount, recipient, network, expiry and replay itself, but relies on the facilitator for signature validity and settlement.

Coinbase CDP key in wp-config.php (recommended)

// Ed25519 key (one line)
define( 'CRYPTOMETER_CDP_KEY_ID', 'your-cdp-key-id' );
define( 'CRYPTOMETER_CDP_KEY_SECRET', 'your-base64-ed25519-secret' );

// or an EC (PEM) key: keep the line breaks as \n inside double quotes
define( 'CRYPTOMETER_CDP_KEY_SECRET', "-----BEGIN EC PRIVATE KEY-----\nLINE1\nLINE2\n-----END EC PRIVATE KEY-----\n" );

Create the key at portal.cdp.coinbase.com. Ed25519 needs the PHP sodium extension; PEM (ES256) needs openssl. A CDP API key lets your site call the facilitator; it cannot move funds from your receiving wallet. Keep it secret anyway.

06Test payment and demo client

The Monetize card Make a real test payment summarises this. tools/pay-demo.mjs is a small Node.js x402 client; WordPress never loads it.

1. On a staging copy: Monetize on, Test mode, Base Sepolia, x402.org, your receiving wallet saved, and the test bot set to Charge (the Simulator must show 402 for GPTBot). Do not send a login cookie: logged-in users are never charged.
2. Install Node.js (a current LTS; the demo was verified with Node.js 22). Copy the plugin's tools folder to your computer and run npm install inside it (installs viem).
3. Dry run with a random, empty wallet: node pay-demo.mjs https://staging.example.com/some-post/. Expected: a 402, then a retry answered with the facilitator error invalid_exact_evm_insufficient_balance (the random wallet has no USDC). That proves the chain works.
4. Create a throwaway wallet (inside tools):

   node --input-type=module -e "import { generatePrivateKey, privateKeyToAccount } from 'viem/accounts'; const k = generatePrivateKey(); console.log('PRIVATE_KEY=' + k); console.log('ADDRESS=' + privateKeyToAccount(k).address);"

5. Get free testnet USDC for that address at faucet.circle.com (USDC, Base Sepolia).
6. Pay: PRIVATE_KEY=0xYOUR_THROWAWAY_TESTNET_KEY node pay-demo.mjs https://staging.example.com/some-post/. On success it prints ← 200 OK, the decoded PAYMENT-RESPONSE, the access-pass expiry and the start of the article in Markdown; the payment appears in the ledger.

07Earnings and ledger

• Earned (settled payments only), Paid reads, Paying wallets, Unpaid demand ("Value of AI requests that were asked to pay and did not. Not money you are owed — just demand."), for 7/30/90 days, labelled Test data or Live data according to the current mode.
• Payments ledger: When, Post, Bot, Payer (masked), Network, Amount, Status (Settled, Pending, Processing, Unconfirmed, Failed), Transaction (explorer link).
• Export CSV downloads all payments of the current mode as cryptometer-<mode>-<date>.csv with full payer addresses (columns created_at_utc, post_id, url, bot, payer, network, asset, amount_atomic, amount_usdc, status, tx_hash, x402_version, facilitator). Cells starting with = + - @ are prefixed with an apostrophe.
• Recent facilitator errors appears when verify/settle calls failed. A few failures are normal (agents without funds).

Only Settled payments count as earned. Unconfirmed means the facilitator returned a transaction hash but still reported pending after one retry; no content was served; check the explorer. Rows stuck in Processing for over an hour are marked failed by the daily task. Tax treatment of crypto income depends on your country; ask a professional.

08Simulator and loopback test

See your site through an AI bot's eyes (Monetize screen): choose a post and a visitor (GPTBot, ClaudeBot, PerplexityBot, ChatGPT-User, Googlebot, Human visitor or any bot under "All bots") and press Simulate request. You see the verdict (for example "403 GPTBot → Blocked with HTTP 403", or a 402 with the price), the Price breakdown, a ready curl command (Try it from a terminal), the Decoded PAYMENT-REQUIRED header and the Response body the bot receives. The simulation uses a made-up request: no facilitator call, no statistics, your IP is ignored and the rate limit is skipped.

Loopback test (Monetize screen and Bots & rules → Server & cache rules): Run loopback test makes your server request the post's normal URL with a GPTBot user agent and reports the status and the X-CryptoMeter header.

• "WordPress answered the bot directly. The page cache is not in the way." — good.
• "The bot got a 200 without passing through CryptoMeter. A page cache is probably serving AI bots." — see Page caches.