"Memory systems for AI agents" matching MCP servers:

Pay-per-call USDC payment proxy for AI agents. Issue scoped Pay Tokens with hard spending caps and auto-journal every charge to freee / Money Forward / QuickBooks.

MCP server for creating and fiscalizing invoices via solo.com.hr API. Enables AI agents to generate invoices, retrieve invoice details, list invoices, and check next invoice number.

Persistent memory and payment safety for AI agents on Lightning. Enables agents to remember purchases, track vendor reputations, enforce budgets, and share trust signals via Nostr.

Agent Toolkit for Mercado Pago

Accounting AI - MCP server providing AI-powered tools and automation by MEOK AI Labs

Enables AI agents to browse, list, buy, review, and get paid for digital goods through MCP tools, including balance, ledger, checkout-link, upload, and payout operations. All money is simulated demo credits with no payment processor connected, and seller-authored text is returned in safe data envelopes.

Provides a three-layer payment firewall for AI agents, enabling identity verification, risk screening, and execution authorization with on-chain policy enforcement for secure and auditable transactions.

Lets AI agents and developers list a catalog of troubleshooting datasets, preview up to three records per product for free, and get Lightning payment instructions to unlock full structured datasets.

MCP server for matchmaking and dating, enabling users to register, answer a questionnaire, receive daily matches, and send paid greetings through natural language in AI chat interfaces like Claude and ChatGPT.

AI Agent Hub is a pay-per-call API platform for AI agents Every call is billed automatically in USDC using the x402 protocol - there is no API key, no account, and no signup. Agents get instant access to data queries, file storage, and ad impressions, paying only for what they actually use. The same tools are also exposed natively over MCP, so any MCP-capable agent can discover and call them

MCP server that provides tools for retrieving transaction context and recording AI decisions or creating human reviews for payment risk exceptions. Enables LLM agents to handle exception transactions in a hybrid payment-decisioning workflow.

Free x402 endpoint checker plus paid report and metadata tools. Remote MCP server for agents. Written by AI named Nock, not a human.

Enables AI agents to browse product catalogs and make purchases through a policy engine that enforces spending limits, requires human approval for certain amounts, and logs all actions to an audit trail.

Checks live x402 routes across Base, Solana, and Algorand before agents spend. $0.003 USDC settles only for a valid live eligible route; normal typed misses are not settled. Free preview and validate tools. Seller payment is separate; the agent keeps its wallet. Optional signed route-binding receipts support buyer-side checks.

The first commercial implementation of HTTP 402 Payment Required for creator content monetization. AI agents pay $0.0025 per content pull from paywalled creator libraries. Creators get paid automatically.

Enables AI agents to call paid APIs and settle HTTP 402 payment challenges with USDC on Base, without private keys ever being involved.

A paid MCP server that lets AI agents send SMS messages to US phone numbers via x402 micropayments, with automatic compliance and opt-out handling.

Reads and validates any European e-invoice a business receives — XRechnung, UBL, CII, ZUGFeRD/Factur-X PDF, Peppol BIS 3, FatturaPA, KSeF FA(3) — into canonical EN 16931 JSON with plain-language fix hints in EN/DE/PL/IT/FR, plus PDF, CSV and DATEV export. Nothing is stored; works without a key on a small daily quota.

Enables AI agents to discover and pay for x402-gated HTTP APIs, handling 402 Payment Required flows with local signing. Supports EVM and Solana with non-custodial wallet management.

Keyless crypto payments for AI agents. One MCP call turns any wallet address into a non-custodial crypto payment link or tip jar, no API key and no account, with funds settling straight to your wallet at a 0% platform fee (USDC/USDT, BTC, LTC, DASH, DOGE, ZCASH).