"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.

Provides six read-only MCP tools for checking an agent reply against explicit rules and preserving exact findings as regressions.

Scores any remote MCP server for readiness across the Claude Directory, ChatGPT Apps, Gemini Connected Apps, and MCP Registry, returning a 0–100 score, A–F grade, per-store status, failing checks, and one-line fixes. Also provides report links, badges, and explanations of each check.

Enables agents to verify that a deploy actually worked by checking pages, links, and comparing environments, catching blank 200 responses, broken links, stray noindex, and staging that never updated.

Runs SQL statements in memory against real PostgreSQL 18 and SQLite 3.49 engines after loading your schema and sample rows, returning each statement's own verdict: errors with line, column, and hints, constraint violations, or the resulting rows. It also compares both dialects to expose portability differences, all with no database server, network, or API key.

Reads a small-business website like a customer would and shows where they get stuck. Every AI answer has to quote the page, and the server checks the quote before it counts.

Enables agents and users to validate Kubernetes manifests (YAML/JSON, multi-document) against the API of a chosen Kubernetes version without needing a cluster. It reports removed or deprecated APIs with replacements, unknown or misspelt fields, misconfigurations the API server would reject, Pod Security Standard violations, and common risks, each with file, line, and fix.

Analyzes websites for broken links, missing meta tags, and redirect chains, returning a health score and actionable suggestions.

Custom version of vibecheck

Enables Codex and Claude Code agents to submit drafts for local rubric-based review through TypeSafe Jev, returning keep, rewrite, or uncertain decisions so agents can fix flagged issues and re-check once.

Enables deliverable conformance and evidence-chain checks by turning requirements into executable specs, validating numbers against a provenance ledger, and auditing PDF/OOXML metadata and archive manifests.

Enables running deterministic package.json checks for Next.js, Expo, and Convex projects via a read-only stdio tool, returning JSON findings usable by CI and coding agents.

Enables AI coding assistants to scan an iOS, Android, Flutter, React Native or Expo project for App Store and Google Play rejection risks, returning deterministic findings that cite the guideline section, link to the official Apple or Google page and explain how to fix each problem. Nothing leaves the machine and no AI is used in the checks.

Serves the paper fact-checking checks over the Model Context Protocol, enabling an agent to recompute reported statistics, percentages and changes, compare text against tables, and verify references against Crossref, OpenAlex and arXiv. Each finding quotes the paper, shows the arithmetic and suggests a fix, with HTML, Markdown and JSON reports.

Minimal MCP server for testing GitHub PR checks pipeline, with deterministic tools echo, add, and server_info.

Enables AI agents to submit npm, PyPI, Go, or Maven packages and manifests to the free OSV.dev database and receive per-package and per-advisory results with CVE mappings, CVSS scores, severities, and the versions that fix each issue. It also supports filtering by minimum severity, de-duplicating alias advisories, and machine-readable error/warning rows for CI gates and upgrade recommendations.

Provides a check_links tool that lets AI apps verify up to 200 URLs at once, returning status codes, redirect chains, final URLs, and connection errors.

Enables turning requirements documents into RFCs, functional test scenarios, and a traceability matrix, with tools to parse, diff, and verify coverage.

Automates the conversion of Figma designs into TypeScript React components and integrates with GitHub to create pull requests for the generated code. It includes visual regression testing with Playwright and accessibility validation to ensure implementations match the original designs.

Enables agents to turn a plain-language description of a device into a complete, validated build package — parts list, 3D-printable parts, wiring, firmware code, picture assembly guide, and tests — that anyone can assemble without electronics experience.

Enables validation of Shopify product CSV exports before import, detecting duplicate or whitespace-colliding SKUs, missing variant data, repeated option combinations, and conflicting metadata, returning a SHA-256-bound JSON diagnostic report.

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

Provides a testable gateway path for running a local MCP-style server in hosted-like conditions, with tenant-isolated reads, approval-denied writes, deterministic failures, and smoke-test verification.

Free JSON Schema validation, JSON to TypeScript, CSV to JSON, JSON repair and JSON to CSV for AI agents. Hosted MCP plus local STDIO. Connect once with a scoped key; enforce tool allowlists and quotas, inspect request IDs. Runnable repair → validate → CSV workflow. Bounded OpenAPI and webhook checks. No LLM calls or payments. Setup: invokeport.com/agents.

Multi-dimensional data quality validation and statistical anomaly detection for LLM training data, with auto-fix pipeline and MCP tools for AI IDE integration.

Enables MCP clients such as Claude Desktop and Claude Code to read café rules, rota, and staff data, check proposed rota changes against the owner's rules, and evaluate customer chat replies before sending. Every tool is read-only, with code checks applied first and AI judging used only when needed.

Enables an AI assistant to run pre-ingest QA on utility power-grid GIS exports: score readiness, list issues with coordinates, reconcile registers against survey/LiDAR detections, map codes to library types, and draft a data request. It exposes the same checks, reconciliation and reporting operations as callable tools so a deployment engineer can work conversationally in any MCP client.

Automates downloading mobile game performance data from PerfDog and converts it to Tableau-ready CSV format with device statistics, FPS metrics, and time-series data.

Programmatic email deliverability testing for AI agents. Create inbox placement tests across Gmail, Outlook, Yahoo, Mail.ru, Yandex — get per-provider placement (Inbox/Spam/Promotions), SPF/DKIM/DMARC auth, Rspamd & SpamAssassin verdicts, DNS health (MX, PTR, DNSBL), and live SSE results.

Enables migration of test automation projects from WebDriverIO to Playwright using AST-based transformations. Provides tools for analyzing tests, converting syntax, refactoring to Page Object Model, and generating migration reports.