"A search query containing special characters and SQL injection-like encoding" matching MCP servers:

A Model Context Protocol server providing tools for querying Bitcoin blockchain data via Blockchain Data and Query APIs, supporting various BTC information retrieval functions.

A bridge that connects Dune Analytics blockchain data to AI applications through Model Control Protocol, allowing LLMs to access on-chain data via natural language interactions.

This MCP wraps Bitrefill public API to allow agents to search for products and shop using cryptocurrencies like Bitcoin, Ethereum, Solana, and many more.

Cross-chain cryptocurrency swaps via Chainflip. Get quotes, execute swaps, and track progress. No API key required to get started.

Exposes Base mainnet chain query tools over MCP, letting clients fetch an address's native balance and current gas fee estimates (slow/standard/fast urgency) from an upstream HTTP API. Paid tools are gated by x402 micropayments settled through the CDP facilitator, with a free health check and a documented free-trial allotment.

MCP server that lets AI agents search the substreams.dev package registry.

Read-only MCP server for discovering and ranking on-chain agents on Stellar mainnet via natural language search, reputation probes, and profile lookups.

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

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

Wallet-funded MCP client for six paid Utilia tools: Solana priority fees, transaction diagnosis and simulation, token-risk checks, PDF-to-Markdown, and audio normalization over x402. MIT-licensed and installable from npm.

A pure-Python MCP server providing local byte-wrangling utilities including encoding, hashing, number conversion, and Ethereum primitives, with no network calls required.

MCP server for Crypto APIs Utils, enabling address validation, raw transaction decoding, and XRP X-Address encoding/decoding for UTXO, EVM, and XRP blockchains.

Enables AI agents to query entities from Arkiv database chains using a SQL-like filter expression, with pagination and configurable fields.

A Model Context Protocol server that allows AI assistants like Claude to directly query cryptocurrency and blockchain project data from RootData, including project information, organization details, and search results.

Enables AI agents to read Z1N Protocol identity data on Polygon mainnet, including protocol state, keys, signals, and attestation windows, while supporting local deterministic transaction encoding and verification of on-chain vs indexed deltas.

A Model Context Protocol server that enables seamless integration with Polymarket, providing tools to search markets, fetch events, analyze leaderboards, query user activity, and more via MCP-compatible clients like Claude.

Enables MCP-compatible AI agents to manage Mandates and execute USDC-denominated trades on Arc, including checking equity, holdings, active rules, available loss headroom, fetching Chainlink prices, and swapping approved assets. Rule violations such as excessive trade size, insufficient balance approvals, expired deadlines, or transfers involving unauthorized recipients produce clear failure states containing actionable guidance.

Enables agents to query Base blockchain data using natural language by providing contract addresses, SQL templates, and direct access to Coinbase's SQL API for realtime on-chain analytics including DeFi, NFTs, and wallet activity.

Enables MCP hosts like Claude and Cursor to query Polymarket data via Falcon AI's external API, including market listings, order books, and trader stats.

Enables AI assistants to query on-chain data across EVM chains like Base, Optimism, Avalanche, Celo, and Arbitrum, including balances, transactions, gas, and smart contract interactions.