"How to check Bitcoin (BTC) balance" matching MCP servers:

Runs a regular expression on real engines — JavaScript (V8), Python (CPython re), PCRE2 and RE2 — reporting each engine's own compile errors with positions, every match with its groups and named groups, replacement results, and where the engines disagree. It also detects catastrophic backtracking (ReDoS), naming the at-risk part of the pattern, generating an attack string, and timing how long each engine actually takes on it.

Enables AI agents to have planned actions checked before execution and to retrieve signed receipts for past checks, with tools for describing and explaining the ruleset.

Enables AI coding agents to audit Supabase or Postgres databases for Row Level Security and multi-tenant isolation holes, reading tables, grants, policies and functions for static findings and optionally probing those policies inside a rolled-back transaction. It reports each hole with an explanation and a fix, so an agent can verify the migrations it just wrote before declaring them done.

Retired. This MCP wrapper is no longer maintained. Check is now a Claude Code hook: npx @golproductions/check@latest --install. 120 free messages a day. Details: golproductions.com/check

Enables AI agents to scan directories, container images, and SBOMs for vulnerabilities, look up individual CVEs, and refresh the local vulnerability database. Findings come back prioritized with concrete upgrade targets rather than raw scanner output.

Enables AI coding agents to inspect GitHub repositories and shell commands for download-and-execute payloads, obfuscation, typosquatted dependencies, autorun hooks, and fake-star signals before following or running them.

Lets AI agents check whether an EVM wallet address carries an EIP-7702 delegation across eight chains (Ethereum, Base, BNB Chain, Arbitrum, OP, Polygon, Gnosis, Unichain) and learn how to obtain a deeper paid report with delegate bytecode heuristics and risk levels. Read-only, never touching private keys or seed phrases.

Read-only Supabase RLS check: explains in Arabic which tables anyone can read or change. No keys.

Enables checking whether a crypto link is a phishing lookalike of a wallet, exchange or dapp by comparing it against official domains and flagging lookalike characters, typosquats, punycode and bait words, fully offline. An optional paid full check adds domain registration age, DNS, redirect tracing and a page scan for seed-phrase prompts and drainer code.

Enables production-grade answer verification for LLM agents by independently re-checking answers with a configurable verifier model, enforcing confidence policies, and producing Ed25519-signed, auditable verification results with optional web search and knowledge-base evidence.

Enables reviewing GitHub Actions workflows for outdated actions, deprecated Node runtimes, retired runners, deprecated commands, and security risks, with file, line, and fix for each finding.

Enables agents to validate Dockerfiles for build-breaking syntax errors, risky patterns like root users and secrets in ENV/ARG, and cache-order problems, returning every finding with its line and a fix. It also verifies referenced container images against public registries, reporting tag existence, digests to pin, supported platforms, last rebuild time, and end-of-life status with an upgrade tag.

Enables AI agents to check whether a domain loads securely in a browser, including certificate validity and expiry, and to pull public homepage facts such as title, language, CMS, contact emails, phones, and social links. It also searches a small dated local-business index by category and area.

An MCP server that detects potential risks in Solana meme tokens, helping AI agents avoid rug pulls and unsafe projects.

MCP server that lets agents check domain email authentication (SPF, DKIM, DMARC, MX) via a free API, returning grades and shareable report URLs. Also provides tools for listing paid services and partner program terms.

Free wallet-OFAC SDN screening and trust-check preview for AI agents on Base. Single MCP tool call returns allow/block verdict against US Treasury OFAC SDN list.

Enables read-only comparison of Stripe active entitlements against an application's effective access snapshots, returning matched, mismatch, or unknown results for agent-driven diagnostics.

Scans repositories for owner identifiers and secrets, blocking pushes or CI merges if any are found.

Enables users and AI agents to verify whether a crypto recipient address is an address-poisoning lookalike or has an invalid EIP-55 checksum before sending funds, and provides access to an on-chain history scan for suspicious transfers.

Enables coding agents to check individual project dependencies or local CycloneDX/SPDX SBOM files against the public OSV.dev advisory database and receive ranked vulnerability findings.

An MCP server that enables interaction with the Firebase App Check API, allowing users to verify and manage the authenticity of requests to Firebase backend services through natural language.

Detects whether sensitive data like emails, SSNs, and phone numbers survive in supposedly redacted PDFs, running entirely locally via WebAssembly.

An MCP server that sends plain-text Gmail messages only to a predefined allowlist, using generated recipient IDs instead of email addresses to enforce security.

Enables AI agents to perform compensating-control lifecycle operations on Check Point firewalls, including adding access rules, publishing sessions, and installing policies.

Enables AI agents to analyze images from a URL, local path, or Base64 string and determine whether they are AI-generated, including detection of signatures from Flux, Midjourney, DALL·E, and Stable Diffusion. Also inspects cryptographic C2PA provenance manifests, signing certificate authorities, and camera EXIF metadata without requiring API keys or accounts.

Enables AI assistants to manage Check Point CloudGuard WAF configuration through natural language, including assets, profiles, practices, and policy.

Enables AI agents to triage security events, search scanned emails and files, quarantine or restore messages, and manage allow/block exception rules through the Harmony Email & Collaboration API. Runs as a stateless, multi-tenant streamable HTTP endpoint where credentials are supplied per request as headers and never stored.

HallucC — an MCP server for hallucination detection and AI agent safety. Claim-by-claim fact-checking of LLM/agent output with cited sources, a prompt-injection & jailbreak guard, and L0–L3 risk gating for computer-use (CUA) agent actions. 5 tools, 3 free checks/day, works with Claude Code, Cursor and Claude Desktop.

Enables Claude to list Iceberg tables and run read-only DuckDB SQL queries, including time travel by snapshot, with per-caller token authentication and audit logging.

MCP server that enables AI agents to check if email addresses or domains are disposable using the isitdisposable.com API. It provides tools like check_email, check_domain, and check_batch for real-time validation.