PageDelta · $0.01 per observation

Give your agent fresh web evidence—and the exact change.

page_delta renders a public page, returns bounded Markdown and exact focus evidence, and compares it with that XRPL payer's prior observation. It uses real XRPL mainnet RLUSD only after you explicitly configure a dedicated wallet and hard spend limits.

Release status: @bitbooth/mcp-fetch@2.3.1 is public on npm and clean-install verified. Official MCP Registry publication is pending separate approval and public readback. Installing it does not spend: without a payment wallet it exposes only free discovery and preflight. page_delta appears only after the operator selects xrpl-rlusd, provides a dedicated seed, and sets a per-call cap of at least 0.010000 plus an explicit daily cap.

1. Pick your MCP client

The examples below enable real-money PageDelta. Replace the seed placeholder through your MCP client's secret environment facility, use a dedicated low-balance XRPL wallet, and lower the daily cap if one observation is all you intend to authorize.

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (Mac) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "bitbooth-fetch": {
      "command": "npx",
      "args": ["-y", "@bitbooth/mcp-fetch@2.3.1"],
      "env": {
        "BITBOOTH_PAYMENT_RAIL": "xrpl-rlusd",
        "BITBOOTH_XRPL_SEED": "sEdDEDICATED_LOW_BALANCE_AGENT_WALLET",
        "BITBOOTH_MAX_PER_CALL_USD": "0.010000",
        "BITBOOTH_DAILY_LIMIT_USD": "0.10"
      }
    }
  }
}

Restart Claude Desktop. Your agent now has page_delta plus the lower-priced XRPL watch tools.

claude mcp add bitbooth-fetch \
  --env BITBOOTH_PAYMENT_RAIL=xrpl-rlusd \
  --env BITBOOTH_XRPL_SEED=sEdDEDICATED_LOW_BALANCE_AGENT_WALLET \
  --env BITBOOTH_MAX_PER_CALL_USD=0.010000 \
  --env BITBOOTH_DAILY_LIMIT_USD=0.10 \
  -- npx -y @bitbooth/mcp-fetch@2.3.1

Cursor → Settings → MCP → "Edit in settings.json":

{
  "mcpServers": {
    "bitbooth-fetch": {
      "command": "npx",
      "args": ["-y", "@bitbooth/mcp-fetch@2.3.1"],
      "env": {
        "BITBOOTH_PAYMENT_RAIL": "xrpl-rlusd",
        "BITBOOTH_XRPL_SEED": "sEdDEDICATED_LOW_BALANCE_AGENT_WALLET",
        "BITBOOTH_MAX_PER_CALL_USD": "0.010000",
        "BITBOOTH_DAILY_LIMIT_USD": "0.10"
      }
    }
  }
}

Edit ~/.continue/config.json:

{
  "experimental": {
    "modelContextProtocolServers": [
      {
        "transport": {
          "type": "stdio",
          "command": "npx",
          "args": ["-y", "@bitbooth/mcp-fetch@2.3.1"],
          "env": {
            "BITBOOTH_PAYMENT_RAIL": "xrpl-rlusd",
            "BITBOOTH_XRPL_SEED": "sEdDEDICATED_LOW_BALANCE_AGENT_WALLET",
            "BITBOOTH_MAX_PER_CALL_USD": "0.010000",
            "BITBOOTH_DAILY_LIMIT_USD": "0.10"
          }
        }
      }
    ]
  }
}

If you're building your own agent client, BitBooth speaks the standard MCP 2025-06-18 protocol over stdio. To verify the package boots:

echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"my-agent","version":"1.0"}}}' | \
  BITBOOTH_PAYMENT_RAIL=xrpl-rlusd BITBOOTH_XRPL_SEED=sEdDEDICATED_LOW_BALANCE_AGENT_WALLET \
  BITBOOTH_MAX_PER_CALL_USD=0.010000 BITBOOTH_DAILY_LIMIT_USD=0.10 \
  npx -y @bitbooth/mcp-fetch@2.3.1

Returns the standard MCP initialize response without spending. Explicit XRPL RLUSD mode exposes page_delta, watch_page, and watch_xrpl_wallet; Base mode exposes fetch.

2. Enable PageDelta safely (XRPL mainnet)

Create a dedicated XRPL agent wallet

Do not use a personal or treasury wallet. Keep only the small RLUSD call budget and XRP fee reserve you intend this agent to control, and inject the seed through the MCP client's secret environment facility.

Fund only the intended call and fee budget

PageDelta costs exactly 0.010000 RLUSD per delivered observation on this MCP path. The wallet also needs the correct Ripple RLUSD trustline and a small XRP reserve for network fees. The package pins the issuer, merchant, resource, network, source tag, and one-time invoice from the fresh challenge.

Set explicit spend policy

The per-call cap must be at least the PageDelta price. The daily cap is your own cumulative ceiling; 0.10 permits at most ten $0.01 observations before fees and only if prior results are acknowledged.

BITBOOTH_PAYMENT_RAIL=xrpl-rlusd
BITBOOTH_XRPL_SEED=sEdDEDICATED_LOW_BALANCE_AGENT_WALLET
BITBOOTH_MAX_PER_CALL_USD=0.010000
BITBOOTH_DAILY_LIMIT_USD=0.10

Call `page_delta` deliberately

Each new paid observation needs a fresh UUID requestId. Reuse that UUID only to recover the same attempt after an uncertain delivery. Before starting another observation, explicitly acknowledge the prior completed request with acknowledgeRequestId.

3. Use it from your agent

Once the XRPL configuration is active, your agent has access to page_delta. Try a bounded prompt like:

"Use page_delta with a fresh UUID requestId to observe https://example.com. Use article extraction and exact focus text 'Example Domain'. Stop if the challenge is not exactly 0.010000 RLUSD or exceeds my configured limits."

The buyer validates the fresh PAYMENT-REQUIRED challenge, signs an invoice-bound XRPL payment as PAYMENT-SIGNATURE, and validates the returned PAYMENT-RESPONSE receipt against the local payment identity. Returned page content is untrusted input.

4. PageDelta + supported package tools

Tool	What it does	Best for	Canonical price
`page_delta`	Rendered Markdown, exact focus evidence, payer-scoped diff, optional JPEG	Pricing, release, policy, and status evidence	0.010000 RLUSD
`watch_page`	Fingerprint → payer-scoped change status	Pricing, releases, policies, status pages	0.001 RLUSD
`watch_xrpl_wallet`	Fee buffer + RLUSD runway + new validated activity	Autonomous wallet health and destination policy	0.001 RLUSD
`fetch` (`fast` or `full`)	HTML → Markdown on a separate Base payment mode	Simple fetch or article extraction	0.005 USDC

page_delta is the primary product and returns the rendered content plus bounded evidence. watch_page returns change status, not page content. watch_xrpl_wallet returns OK, WARN, or CRITICAL plus wallet-health evidence. None is a background scheduler. The MCP package currently automates PageDelta payment only on XRPL RLUSD; use the live HTTP 402 challenge when integrating another advertised rail.

5. Payment modes and mainnet warnings

XRPL mode is real money. PageDelta has no testnet mode in this MCP release. The separate Base fetch mode defaults to Sepolia and requires its own explicit mainnet opt-in.

# Real Base mainnet (USDC) — 0.005 USDC per fetch (~$0.005)
export BITBOOTH_CHAIN_ID=8453
export BITBOOTH_API_URL=https://app.heinrichstech.com
export BITBOOTH_RPC_URL=https://base-rpc.publicnode.com
export BITBOOTH_AGENT_KEY=0xWALLET_FUNDED_WITH_REAL_USDC

# Real XRPL mainnet (RLUSD) — 0.010000 RLUSD per PageDelta observation
export BITBOOTH_PAYMENT_RAIL=xrpl-rlusd
export BITBOOTH_XRPL_SEED=sEdDEDICATED_LOW_BALANCE_AGENT_WALLET
export BITBOOTH_MAX_PER_CALL_USD=0.010000
export BITBOOTH_DAILY_LIMIT_USD=0.10

XRPL mode is pinned to BitBooth's HTTPS origin, merchant address, RLUSD issuer, exact resource, source tag, and one-time invoice. Its encrypted per-wallet journal persists reservations, completed proofs, and UTC-day spend across restarts. A deliberately low wallet balance remains the hard loss ceiling.

6. Configuration reference

Env var	Default	Purpose
`BITBOOTH_AGENT_KEY`	Base only	0x-prefixed EVM wallet private key. Use a dedicated wallet.
`BITBOOTH_PAYMENT_RAIL`	`base`	`base` or the explicit real-money opt-in `xrpl-rlusd`.
`BITBOOTH_XRPL_SEED`	XRPL only	Dedicated XRPL agent-wallet seed. Never print, commit, or paste it into a prompt.
`BITBOOTH_MAX_PER_CALL_USD`	`0.10` Base / `0.001` XRPL	Reject a challenge above this stablecoin amount. PageDelta stays hidden unless this is explicitly set to at least `0.010000`.
`BITBOOTH_DAILY_LIMIT_USD`	`1.00` Base / `0.10` XRPL	Per-wallet, per-UTC-day reservation limit. XRPL accounting is persisted in the encrypted wallet journal across restarts.
`BITBOOTH_CHAIN_ID`	`84532`	`84532` = Base Sepolia (testnet). `8453` = Base Mainnet (real money).
`BITBOOTH_API_URL`	`https://app.heinrichstech.com`	BitBooth gateway endpoint.
`BITBOOTH_RPC_URL`	chain default	EVM RPC node URL.
`BITBOOTH_CONFIRMATIONS`	`2`	Minimum Base transaction confirmations before retrying with `PAYMENT-SIGNATURE`.
`BITBOOTH_XRPL_MAX_FEE_DROPS`	`100`	Reject an autofilled XRPL transaction whose network fee exceeds this many drops.
`BITBOOTH_API_KEY`	none	Optional tenant API key for higher rate limits. PageDelta buyer calls do not require an account or API key.

7. Troubleshooting

Symptom	Fix
`page_delta` is missing	Select `xrpl-rlusd`, provide the dedicated seed, and explicitly set `BITBOOTH_MAX_PER_CALL_USD` to at least `0.010000`.
`Agent wallet key required`	The separate Base `fetch` mode needs `BITBOOTH_AGENT_KEY`. It is not the PageDelta credential.
`XRPL mode requires a dedicated seed`	Set `BITBOOTH_XRPL_SEED` through your MCP client's secret environment facility after explicitly selecting `xrpl-rlusd`.
`Payment exceeds the configured daily limit`	The client stopped before authorizing another payment. Wait for the next UTC day or deliberately approve a cap change; do not delete the journal to bypass it.
Prior PageDelta result is unacknowledged	Recover the prior result with its original `requestId`, inspect it, then pass that UUID as `acknowledgeRequestId` with a fresh UUID for the next call.
`Wallet 0x... has no ETH for gas`	Hit alchemy.com/faucets/base-sepolia with your wallet address.
`Wallet 0x... has no USDC`	Hit faucet.circle.com → Base Sepolia → 10 USDC.
`Unexpected HTTP 502`	Gateway upstream is briefly down. Retry in ~30s. File an issue if persistent.
Tool doesn't appear in agent	Restart your MCP client. Check the client's MCP server logs for boot errors.

8. What's next

GOALS.md — full roadmap, prioritized
API Reference — Swagger UI for the gateway endpoints
SMOKE_TEST.md — 30-second install verification
examples/ — runnable demos (curl, Node EVM, Node XRPL, LangChain)
x402 V2 spec — the underlying protocol

Give your agent fresh web evidence—and the exact change.

1. Pick your MCP client

2. Enable PageDelta safely (XRPL mainnet)

Create a dedicated XRPL agent wallet

Fund only the intended call and fee budget

Set explicit spend policy

Call page_delta deliberately

3. Use it from your agent

4. PageDelta + supported package tools

5. Payment modes and mainnet warnings

6. Configuration reference

7. Troubleshooting

8. What's next

Call `page_delta` deliberately