loop-mcp
15 pay-per-call Bitcoin and developer tools, paid in sats over Lightning (L402).
Connect it
Settings → Connectors → Add custom connector
URL: https://mcp.loopxxi.com/mcpSettings → Apps & Connectors → Advanced → Developer mode
Create connector with URL: https://mcp.loopxxi.com/mcp{
"mcpServers": {
"loop-mcp": {
"url": "https://mcp.loopxxi.com/mcp"
}
}
}claude mcp add --transport http loop-mcp https://mcp.loopxxi.com/mcp{
"servers": {
"loop-mcp": {
"type": "http",
"url": "https://mcp.loopxxi.com/mcp"
}
}
}15 tools, verified live
btc_priceread-onlyGet the current Bitcoin price in USD and other major currencies. Source: mempool.space. Real-time.
btc_send_decisionread-onlyReturns a composited send-or-wait recommendation for a Bitcoin transaction. Fetches live mempool and fee data, then outputs a machine-actionable verdict (SEND_NOW, WAIT, or URGENT_ONLY) with fee rates in sat/vB, mempool pressure level, and estimated savings if you wait. Ideal for agents that need a single decision call instead of parsing multiple raw mempool endpoints.
lightning_address_resolveread-onlyResolve a Lightning Address (user@domain.com) to a payable BOLT11 invoice for a given amount. Handles the full LNURL-pay protocol internally. Returns the invoice plus min/max sendable amounts for validation.
tx_decode_explainread-onlyFetch a Bitcoin transaction by txid and return a structured, agent-ready summary: type (P2WPKH/P2TR/P2SH/etc.), input/output counts, fees, fee rate in sat/vB, confirmation status, RBF flag, SegWit/Taproot flags, and a one-line agent_summary string ready for LLM context injection. Saves 500-2000 tokens vs parsing raw TX JSON.
optimal_send_windowread-onlyBitcoin transaction timing intelligence. Returns a congestion forecast for the next 1-4h, a recommended UTC send window when fees are projected at/below your target, a fee trajectory (rising/stable/falling) with a calibrated confidence score, next-block minimum fee, confirmation targets for 3/6/144 blocks, and an RBF-viability flag. A synthesis layer above raw fee data — the decision an autonomous
json_validateread-onlyValidate JSON, identify its root type, and return normalized JSON plus a SHA-256 content hash.
json_extractread-onlyExtract one value from JSON using a simple dot path with array indexes, for example users[0].email.
csv_to_jsonread-onlyConvert CSV, TSV, semicolon, or pipe-delimited text into structured JSON with bounded row output.
text_analyzeread-onlyReturn deterministic text statistics, estimated tokens, reading time, and a SHA-256 content hash.
hash_generateread-onlyGenerate a SHA-256 or SHA-512 digest in hexadecimal or Base64 form.
base64_convertread-onlyEncode UTF-8 text to Base64 or decode Base64 safely, with standard and URL-safe alphabets.
timestamp_convertread-onlyConvert Unix seconds, Unix milliseconds, RFC3339, or ISO dates into normalized UTC timestamp forms.
uuid_generateread-onlyGenerate one to one hundred cryptographically random RFC 4122 UUID version 4 identifiers.
url_parseread-onlyParse an HTTP or HTTPS URL into normalized scheme, host, port, path, query, and fragment fields without fetching it.
jwt_decoderead-onlyDecode JWT header and payload claims locally without verifying the signature. The response always marks verification as false.
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