@bitbooth/mcp-fetch

@bitbooth/mcp-fetch

An agent-facing x402 catalog and buyer shipped as one MCP server. Discover and preflight BitBooth APIs for free, fetch a URL over Base USDC, or explicitly opt into XRPL mainnet RLUSD for PageDelta, lightweight page watching, and XRPL wallet-runway monitoring.

What makes this worth paying for: page_delta renders a public page, returns bounded Markdown and exact focus evidence, compares it with that payer's prior observation, and may include a bounded JPEG snapshot. It also returns hashes, an opaque tracking cursor that never authorizes access, a content-bound observation ID that is not a public attestation, and settled payment metadata. Web content is always marked untrusted.

🧭 Scope: discover_bitbooth and preflight_bitbooth are free and available in every rail mode, even without a wallet credential. Base remains the default paid rail and exposes fetch. Explicit xrpl-rlusd mode exposes the 0.001-RLUSD watch tools and keeps page_delta visible for recovery. New PageDelta signing requires an explicit per-call cap of at least 0.010000; a zero, omitted, or subsequently lowered cap permits only exact recovery of an already-signed proof. The live catalog at /bazaar.json is canonical.

✅ Verified on-chain — BitBooth's XRPL merchant receipts are public on the XRPL AI profile.

🛡️ Testnet by default. A fresh install uses Base Sepolia. XRPL is mainnet-only and requires both an explicit rail selection and a separate XRPL seed.

Install

Version 2.3 required for PageDelta: this release keeps the request-bound Base proof from 2.x and adds PageDelta to the serialized XRPL buyer. Keep the ^2.3.0 pin below so older clients cannot expose an incompatible tool contract.

MCP-native — drop into Claude Desktop, Claude Code, Cursor, Windsurf, Continue, or any MCP-compatible client. The snippet below matches the canonical install on app.heinrichstech.com.

Claude Desktop / Cursor / Windsurf / Continue

Paste into claude_desktop_config.json (Claude Desktop), .cursorrules.mcp.json (Cursor), or your client's MCP config:

For free catalog discovery and preflight, no wallet is required:

{
  "mcpServers": {
    "bitbooth": {
      "command": "npx",
      "args": ["-y", "@bitbooth/mcp-fetch@^2.3.0"]
    }
  }
}

Add a dedicated testnet wallet to enable the paid fetch tool:

{
  "mcpServers": {
    "bitbooth": {
      "command": "npx",
      "args": ["-y", "@bitbooth/mcp-fetch@^2.3.0"],
      "env": {
        "BITBOOTH_AGENT_KEY": "0x<your-testnet-wallet-private-key>",
        "BITBOOTH_MAX_PER_CALL_USD": "0.10",
        "BITBOOTH_DAILY_LIMIT_USD": "1.00"
      }
    }
  }
}

Claude Code

claude mcp add bitbooth -- npx -y @bitbooth/mcp-fetch@^2.3.0

Set your agent wallet key:

export BITBOOTH_AGENT_KEY="0x<your-testnet-wallet-private-key>"

Global install

npm install -g @bitbooth/mcp-fetch@^2.3.0
mcp-fetch   # runs on stdio

Get a testnet wallet + USDC (free, 2 minutes)

• Generate an EVM wallet or use an existing one you control
• Fund it with Base Sepolia ETH (gas): https://www.alchemy.com/faucets/base-sepolia
• Fund it with Base Sepolia USDC: https://faucet.circle.com (select Base Sepolia)
• Set BITBOOTH_AGENT_KEY to the wallet's private key (0x...)

Usage

Every install exposes two free tools that never sign or submit a payment:

discover_bitbooth(
  query: "repair malformed JSON",
  category: "utility",
  maxPriceUsd: 0.01,
  network: "eip155:8453",
  limit: 10
)

preflight_bitbooth(
  route: "json-repair",
  maxPriceUsd: 0.01,
  network: "eip155:8453"
)

discover_bitbooth fetches and validates the live catalog, then returns concise JSON with matching routes and advertised payment requirements. Set configuredOnly: true to filter to the MCP server's configured network and asset instead of browsing all rails.

preflight_bitbooth accepts an exact route name, path, or URL and either selects one compatible advertised requirement under the hard price ceiling or returns a structured no_match. If network or asset is explicit, that filter wins, but it does not reconfigure the buyer: the selected requirement must still match the server's configured payment rail. Otherwise preflight uses that configured rail automatically. Its output always contains paymentAuthorized: false. A buyer must still compare the selection with the live HTTP 402 challenge before signing.

With a Base wallet configured, your agent also gets the paid fetch tool:

fetch(url: "https://example.com", mode: "full")

Modes:

Mode	Price	Description	Best for
fast	0.005 USDC	Raw HTML converted to markdown	Quick lookups, static pages
full	0.005 USDC	Article extraction (Readability) then markdown	Blog posts, docs, news

Returns markdown with title, body, and metadata (URL, timestamp, content length, truncation status).

XRPL RLUSD agent tools

XRPL mode replaces the paid fetch tool with two 0.001-RLUSD watch tools. With an explicit per-call cap of at least 0.010000, it also exposes PageDelta. The free discovery and preflight tools remain available:

watch_page(url: "https://example.com/pricing")

watch_xrpl_wallet(
  address: "rAgentWallet...",
  minCallsRemaining: 10,
  minSpendableXrpDrops: "1000",
  allowedDestinations: ["rKnownMerchant..."]
)

page_delta(
  url: "https://example.com/pricing",
  extract: "article",
  focus: "Enterprise price",
  cursor: "pd1_<cursor-from-the-prior-observation>"
)

watch_page stores a lightweight content fingerprint, then reports meaningful changes on later calls. watch_xrpl_wallet returns OK, WARN, or CRITICAL with spendable XRP after reserves, RLUSD trust-line and paid-call runway, recent validated activity, unfamiliar destinations, and payer-scoped baseline deltas. Omitted wallet-watch policy fields use server defaults: 0.001 RLUSD per planned call, 10 calls remaining, 1,000 spendable drops, no known destinations, and 50 recent transactions.

page_delta costs exactly 0.010000 RLUSD. Its extract value is article (default) or raw; focus is an optional exact, case-sensitive search over the bounded Markdown; and cursor is the opaque value from a prior observation. A missing screenshot is a valid result and is explained in warnings.

To opt in, use a dedicated low-balance payment wallet that holds only the RLUSD and XRP gas budget intended for this agent:

{
  "mcpServers": {
    "bitbooth-watch": {
      "command": "npx",
      "args": ["-y", "@bitbooth/mcp-fetch@^2.3.0"],
      "env": {
        "BITBOOTH_PAYMENT_RAIL": "xrpl-rlusd",
        "BITBOOTH_XRPL_SEED": "sEd<dedicated-agent-seed>",
        "BITBOOTH_MAX_PER_CALL_USD": "0.010000",
        "BITBOOTH_DAILY_LIMIT_USD": "0.10"
      }
    }
  }
}

This is real mainnet spend. BITBOOTH_AGENT_KEY is never used as an XRPL seed, and setting only BITBOOTH_XRPL_SEED does not enable XRPL payments. Keep BITBOOTH_MAX_PER_CALL_USD=0.001 if the agent should have only the watch tools; PageDelta will not be registered. Monitoring the payment wallet itself works, but its own watch payment changes that wallet; for cleaner incident signals, pay from a separate low-balance watchdog wallet.

Pricing

Item	Cost
discover_bitbooth	Free — reads the public live catalog
preflight_bitbooth	Free — selects a requirement but never signs or pays
fast/full	0.005 USDC per fetch
watch_page	0.001 RLUSD per fingerprint comparison
watch_xrpl_wallet	0.001 RLUSD per wallet runway/activity check
page_delta	0.010000 RLUSD per rendered observation and comparison
Gas	Base gas as applicable; XRPL fee is capped at 100 drops by default
Default chain	Base Sepolia (testnet). Explicit opt-in for mainnet.

Configuration

Env var	Description	Default
BITBOOTH_AGENT_KEY	Dedicated EVM agent private key (required only for the paid Base fetch tool)	—
BITBOOTH_PAYMENT_RAIL	base or explicit mainnet opt-in xrpl-rlusd	base
BITBOOTH_XRPL_SEED	Dedicated XRPL seed; required only for xrpl-rlusd	—
BITBOOTH_CHAIN_ID	84532 = Base Sepolia (default, free testnet). 8453 = Base mainnet (real USDC — opt-in).	84532
BITBOOTH_API_URL	BitBooth gateway URL	https://app.heinrichstech.com
BITBOOTH_RPC_URL	EVM RPC endpoint	https://base-sepolia-rpc.publicnode.com
BITBOOTH_CONFIRMATIONS	Tx confirmations to wait before retry (minimum two)	2
BITBOOTH_API_KEY	Optional tenant API key (for higher rate limits)	—
BITBOOTH_MAX_PER_CALL_USD	Maximum stablecoin amount accepted from one challenge; explicitly set at least 0.010000 to expose PageDelta	0.10 Base / 0.001 XRPL
BITBOOTH_DAILY_LIMIT_USD	Per-wallet, per-UTC-day reservation cap; XRPL accounting is durable across restarts	1.00 Base / 0.10 XRPL
BITBOOTH_XRPL_WS_URL	Credential-free WSS endpoint used only to autofill and ledger-bind the signed transaction	wss://xrplcluster.com/
BITBOOTH_XRPL_MAX_FEE_DROPS	Maximum XRP network fee allowed in an autofilled transaction	100

Mainnet opt-in

When you've tested against Sepolia and want to run against real Base mainnet:

export BITBOOTH_CHAIN_ID=8453
export BITBOOTH_API_URL=https://app.heinrichstech.com
export BITBOOTH_RPC_URL=https://base-rpc.publicnode.com   # or your own RPC
export BITBOOTH_AGENT_KEY=0x<mainnet-wallet-with-real-USDC>

The package prints a warning banner to stderr whenever mainnet is active so a misconfig can't silently drain a real wallet.

XRPL safety pins

XRPL mode refuses to pay unless every live PAYMENT-REQUIRED challenge matches all of these values:

• HTTPS origin https://app.heinrichstech.com
• network xrpl:0, scheme exact, and the canonical hex-encoded RLUSD currency
• Ripple RLUSD issuer rMxCKbEDwqr76QuheSUMdEGf4B9xJ8m5De
• BitBooth recipient rfryheo6yzFdLWj8qUQtZc7zG9MKkBkUEy
• exact requested resource URL, a bounded one-time invoice, and the expected source tag
• exactly 0.001000 RLUSD for either XRPL watch tool
• exactly 0.010000 RLUSD for PageDelta on the existing /v1/cdp/render-pro resource

The transaction is last-ledger bounded, partial payments are forbidden, and autofilled recipient, amount, issuer, invoice, memo, and fee fields are checked again before signing. The signed payload is sent as PAYMENT-SIGNATURE; it and the seed are never printed.

watch_page rejects credential-bearing URLs, localhost and .local names, and literal private, loopback, or link-local IPs before requesting a challenge. BitBooth also resolves and checks DNS server-side before settlement to cover rebinding and hostname-to-private-address cases. watch_xrpl_wallet validates classic addresses, numeric bounds, activity limits, and a maximum 25-address allowlist before requesting a challenge.

Programmatic use

Catalog discovery and preflight can be used without constructing a wallet client:

import { createCatalogClient } from '@bitbooth/mcp-fetch/catalog-client';

const catalog = createCatalogClient({ chainId: 8453 });
const choices = await catalog.discover({ query: 'monitor', maxPriceUsd: 0.01 });
const checkout = await catalog.preflight({ route: 'web-watch', maxPriceUsd: 0.001 });
console.log(choices.resources, checkout);

For automatic payment:

import { createX402Client } from '@bitbooth/mcp-fetch/x402-client';

const client = createX402Client({ agentKey: process.env.AGENT_KEY });
const result = await client.fetchWithPayment('https://example.com', 'fast');
console.log(result.markdown);

const watcher = createX402Client({
  paymentRail: 'xrpl-rlusd',
  xrplSeed: process.env.DEDICATED_XRPL_AGENT_SEED,
  maxPerCallUsd: '0.010000',
  dailyLimitUsd: '0.10',
});
const result = await watcher.watchPageWithPayment('https://example.com/pricing');
console.log(result.changed, result.hashes.current, result.baseline);

const health = await watcher.watchXrplWalletWithPayment({
  address: 'rAgentWallet...',
  minCallsRemaining: 10,
  minSpendableXrpDrops: '1000',
  allowedDestinations: ['rKnownMerchant...'],
});
console.log(health.status, health.runway, health.alerts);

const firstRequestId = crypto.randomUUID();
const observation = await watcher.pageDeltaWithPayment({
  requestId: firstRequestId,
  url: 'https://example.com/pricing',
  extract: 'article',
  focus: 'Enterprise price',
});
console.log(observation.diff, observation.focusEvidence, observation.payment);

const nextObservation = await watcher.pageDeltaWithPayment({
  requestId: crypto.randomUUID(),
  acknowledgeRequestId: firstRequestId,
  url: 'https://example.com/pricing',
});

How it works

The free catalog client performs one credential-free GET /bazaar.json, validates the complete remote payload with Zod, and filters locally. It sends no API key, wallet key, seed, signature, or payment header. Preflight is advisory: the eventual buyer must validate the fresh HTTP 402 challenge again.

For Base payments, the package performs the existing request-bound USDC transfer flow. In XRPL mode it reads the base64 PAYMENT-REQUIRED v2 header, selects exactly one pinned RLUSD requirement, checks the route's exact canonical price, reserves spend durably, and only then signs an invoice-bound XRPL Payment and sends the base64 PAYMENT-SIGNATURE. PageDelta uses this same code path—not a second signer or payment loop. The full XRPL lifecycle is serialized per wallet, including across package clients and processes. At most one unresolved proof is retained per wallet; same-request retries reuse it byte-for-byte, while a different request is blocked until the first resolves. page_delta requires a caller-generated UUID requestId: reuse it only to recover the same paid attempt. A validated result remains recoverable until the next PageDelta call supplies a new UUID plus acknowledgeRequestId equal to the prior UUID. The acknowledgement and next reservation are one atomic wallet-document transition. Automatic watch results do not require IDs, stay fresh, and cannot overwrite an unacknowledged explicit PageDelta result.

XRPL proofs, bounded completed results, and the per-wallet UTC-day spend ledger are encrypted together in one per-wallet document using a key derived from the dedicated wallet seed. The document is fsynced and atomically replaced; POSIX ownership/mode and Windows private DACL readback are enforced fail-closed. Set BITBOOTH_XRPL_JOURNAL_DIR only when the MCP host needs a different persistent state directory. After a restart, retry the exact same requestId and input. Never delete this state merely to bypass the block. A lease owned by a live process is not stolen; native HTTP calls are bounded to 30 seconds, and a genuinely wedged host must be terminated before PID-based recovery.

Zero human in the loop. Zero signup. Just pay-per-call via x402.

What endpoints can my agent call

Every mode exposes discover_bitbooth and preflight_bitbooth. Paid tool exposure follows the selected rail: fetch on Base; watch_page, watch_xrpl_wallet, and recovery-capable page_delta on XRPL RLUSD. PageDelta starts new spend only with an explicit per-call cap of at least 0.010000. Agents can call the rest of BitBooth over plain HTTP with a compatible x402 buyer. Prices and route inventory change, so /bazaar.json and the fresh HTTP 402 challenge are canonical.

Federal posture

BitBooth is operated by a service-disabled veteran-owned small business (SDVOSB certified) with an active CAGE code and SAM.gov registration. Defense and federal-contractor teams can procure implementation and managed-operations support through an identifiable U.S. supplier. Details are on the landing page.

Security notes

• BITBOOTH_AGENT_KEY and BITBOOTH_XRPL_SEED are secrets. Use separate dedicated agent wallets, never a personal or treasury wallet.
• Discovery-only installs need neither secret. The catalog client never forwards BITBOOTH_API_KEY or any payment credential to /bazaar.json.
• Default config uses testnet. Never set mainnet keys in a testnet config.
• Base validates the recipient from each payment challenge; all XRPL tools pin the canonical network, issuer, merchant, resource, and route-specific price in code. If delivery fails after settlement, the XRPL proof is retained for safe replay; retry the byte-identical tool request and do not manually submit another payment.
• Base spend reservations are process-local. XRPL reservations and confirmed totals are additionally persisted before signing in the encrypted per-wallet UTC-day ledger, so process restarts cannot reset the configured XRPL daily limit. A signed reservation is released only after a body/header-bound definitive non-settlement response. An unsigned reservation is atomically released if its challenge expires or current caps revoke it.
• The encrypted document and private directory fail closed if the document alone is deleted or corrupted. A malicious user with the same OS account can still delete or roll back all local state; no purely local journal can distinguish that from first use without creating another split-brain state store. Treat the local account as trusted and keep the dedicated agent wallet deliberately low-balance—the on-ledger wallet balance is the hard loss ceiling.

License

MIT