"SearXNG - Open Source Metasearch Engine" matching MCP servers:

Enables AI agents to inspect, check, and audit signed offline spending authorizations, and to issue hash-chained receipts for each action taken against them. Enforces per-transaction, total, expiry, merchant, and human-approval constraints, returning allow, needs_human, or deny with the specific failing constraint.

A standard MCP server for discovering AI agents and negotiating signed skill contracts. Buyer-seller payments are settled directly outside the platform; Agent Economy Engine collects only a platform fee after both parties attest completion.

A read-only MCP server for the open-banking.io PSD2 API that lets AI agents query personal bank balances and transactions via natural language, with zero-knowledge encryption ensuring all sensitive data is decrypted in-process and never exposed to third parties.

Enables Open Payments operations such as creating incoming payments, quotes, and outgoing payments via the Interledger protocol. Supports wallet address retrieval, grant management, and payment flow automation.

Enables Claude to read UK bank account data—balances, transactions, cards, standing orders, direct debits, and identity—through TrueLayer's Data API, with local caching and optional live refreshes. It is read-only by design, requiring consent and never moving money.

MCP server for the Gravv payments API that lets AI assistants onboard customers, run KYC, open accounts, move money, issue cards, and exchange currency, with built-in documentation search and safety confirmations for money-moving operations.

Enables MCP clients to access Monobank's open API for exchange rates, account and jar balances, and statements, as well as set webhooks, using natural language tools.

Enables creating and tracking payment invoices and retrieving watchlist net-worth and source data via the FinCobra Checkout and Watchlist APIs.

Structured product data from the open web — where platform APIs don't reach. Schema.org + AI extraction. Pay per call via Stripe MPP.

MCP server for the PayPay Open Payment API, enabling QR code creation, payment tracking, refunds, and cancellations with sandbox and production support.

Decodes HTTP 402 challenges into exact payment and retry steps, recommends a payment rail from stated requirements, and searches an open registry of scored payment solutions with scheme references and support probing. Every tool is read-only, so nothing can spend money.

Enables MCP clients to get quotes for certified human translations of official documents, upload source files, place and pay orders, and track delivery and payment status.

Marketplace MCP for paid HTTP APIs. Pay per call in USDC on Base via the open x402 standard — non-custodial. 13 tools for discovery, buying, and publishing APIs.

A wallet for AI agents with spending limits: pays x402 and MPP APIs in USDC (Base, Solana, Algorand) and RLUSD (XRP Ledger), checks every payment with presign-guard first, and asks for approval on your phone above your limits. Source in the wallet-mcp folder; npm: presign-guard-wallet-mcp.

Enables Claude to interact with the Open Finance Brasil APIs, allowing users to query accounts, balances, transactions, credit cards, PIX keys, initiate PIX payments, and view investments across supported Brazilian banks using natural language.

Gives your agent a private Kinematic Drive: a deterministic memory engine for sub-millisecond exact recall over code and docs with no hallucination. Also provides self-serve checkout and metered pay-per-call tools for AI agents.

Lets an MCP client find overdue Stripe invoices, see who owes what and how late they are, and re-send reminder emails for invoices that are still open. Runs read-only unless writes are explicitly enabled, re-checks invoice state before sending, and logs every call to an audit trail.

Enables an AI assistant to query Ukrainian software cash register data—receipts, shifts, X/Z reports, goods, and orders—and, only with explicit write permission, to open or close shifts and create fiscal receipts.

Enables Claude Code, Cursor, or any MCP client to ask open and uncensored AI models questions privately, attaching a fresh zero-knowledge proof to each one so the gateway can verify it was paid for without learning who asked. Also lists models and costs, reports remaining questions, and buys new questions with USDC on Solana via x402.

Early-pilot MCP server. search_offers returns sponsored offers with terms; get_tracked_link returns a tracked link plus a disclosure text the agent must show. Public sandbox uses fictional data: no signup, nothing tracked or paid. Open-book pricing: 10% of validated commissions.

Pay-per-use semantic web search for AI agents. Powered by SearxNG, agents pay in sats via Lightning Network micropayments — no API keys required.

Enables AI assistants such as Claude, ChatGPT and Cursor to manage an open-source subscription backend: setting up products, entitlements, offerings and packages, looking up customers, granting or revoking access, adding webhooks, and tracking RevenueCat imports. Tool names mirror RevenueCat's MCP tools, so existing prompts work unchanged.

Connects AI assistants to Quaderno's tax compliance engine, enabling tax calculation, tax ID validation, and invoice creation via natural language.

Universal HTTP 402 Micropayment Protocol & Autonomous Economic Settlement Engine for AI Agents on Base L2.

Open-source sample MCP server built to be audited: ships a paid-tool x402 demo, a deliberately scannable surface, and documented security posture. From Payload, makers of the MCP Launch Readiness Audit (48-rule scanner with a fix for every finding, hardening templates, stress-test harness, readiness verifier, CI workflow, branded audit report) and the MCP Monetization Kit.

Enables users to access a free catalog and samples plus 17 pay-per-call tools, settled in USDC on Base via x402, for web reading, source-bounded summarization, Rioplatense Spanish translation, market and Argentine data, developer utilities, text comparison, and x402-related queries.

Marketplace where AI coding agents fix GitHub bugs for cash bounties. Posters draft and fund bounties from chat (Stripe Checkout); solvers browse open work, request repo access, submit PRs, and get paid in USDC, ETH, or BTC. 11 tools.

A free, open-source MCP server that connects AI assistants to the Tiendanube/Nuvemshop API so they can manage products, variants, stock, orders, fulfillment, customers, coupons, shipping, payments, content and webhooks from plain-language requests. It exposes 191 tools across 39 API resources, with a read-only mode, honest tool annotations and rate-limit-aware, context-friendly responses.

Free, open-source (MIT), local-first Swiss accounting MCP server: an AI agent posts double-entry journal entries, categorises and chases invoices, and prepares the MWST-Abrechnung (the Swiss VAT return), with a minimalist Studio for human oversight. Posted entries are append-only and immutable, corrections are reversing entries, and every query is tenant-scoped.

MCP services for agent security preflight, source scanning, injection screening, proof-of-work policy rehearsal, carbon accounting, climate disclosure and regulatory monitoring. Use each hosted endpoint in the README. Inspect a free quote before buyer-authorized x402/USDC payment. Includes free trust and settlement tools. Maxwell rehearsal does not activate runtime protection.