"An open-source relational database management system" matching MCP connectors:

Structured habitat data and advisory tools for aquariums, marine tanks, terrariums and paludariums.

Measured share of answer for 24 crypto and Web3 brands. An open dataset, not an audit of your site.

Measured share of answer for 20 SaaS brands. An open dataset, not an audit of your site.

Connect Claude or any MCP client to Thread Otter, a GTM agent for founders. Free tools with no key: find_buyer_threads (give it a website URL and get recent Reddit threads where that product's buyers are asking for it, report in ~3 minutes), reddit_demand_board (weekly demand across 40 communities with thread receipts), and subreddit_rules (promotion posture for 2,000+ profiled subreddits). With an API key: read your buying-intent mentions across Reddit, X, LinkedIn, and Bluesky, check your pipeline, and propose posts and reply drafts in your voice. Propose-only by design: nothing sends without your approval flow. Keys at threadotter.com/connect.

Open AI Visibility Index for crypto and Web3. Weekly share-of-answer measurements for 24 tracked brands across ChatGPT, Perplexity and Gemini, from a frozen versioned prompt panel. Five read-only tools: full index, per-brand lookup, brand list, complete measurement history and methodology. No auth, no API key. Data is CC BY 4.0 with a permanent archive of every weekly snapshot, so any figure can be verified independently.

Open AI Visibility Index for SaaS and AI tools. Weekly share-of-answer measurements for 20 tracked brands across ChatGPT, Perplexity and Gemini, from a frozen versioned prompt panel. Five read-only tools: full index, per-brand lookup, brand list, complete measurement history and methodology. No auth, no API key. Data is CC BY 4.0 with a permanent archive of every weekly snapshot, so any figure can be verified independently.

AMZScout Skill + MCP gives AI agents live access to real Amazon marketplace data across 14 Amazon marketplaces. Analyze any ASIN, validate product ideas, research niches, compare competitors, discover profitable keywords, and build data-driven PPC strategies using trusted Amazon insights instead of AI assumptions. Works with Claude, ChatGPT, Cursor, and any other MCP-compatible AI client. To connect, you'll need an AMZScout API plan and authorize your account. Get access and view pricing here: https://learn.amzscout.net/amazon-product-api-for-ai-agents

Closed-source remote MCP: model benchmarks, costs, HN signals, tech registry.

Open scientific and engineering knowledge for AI agents: search, evidence, document publishing.

Search 10,000+ consulting frameworks, templates, financial models, and management case studies

Taiwan stock market data (TWMD): official-source, point-in-time-safe datasets via read-only tools.

An MCP server that gives any LLM or agent clean YouTube transcripts on demand: a single video, a whole channel, or a playlist, plus AI cleanup of auto-generated captions. API-key auth, credit-based, same backend as the public v1 API. Get a free API key with 25 free credits at youtubetranscriptdownload.com/account.

An MCP server that audits the fairness of construction and renovation estimates in Japan. Provides fair-price ranges, overcharge detection, and verifiable unit-cost data based on JCCDB (65,729 items, DOI-backed).

Eligibility-first UK & EU grant discovery, inside ChatGPT and Claude. Checks eligibility before recommending, explains why each grant fits, and cites the funder's own page on every answer — with an honest "competition_risk: unknown" when the data isn't there. 6 tools: search, fetch, find_opportunities, should_apply, explain_opportunity, complete_profile. Transport: Streamable HTTP. Auth: OAuth 2.1 + PKCE. Free to install, no card required.

Validate startup ideas with behavioral evidence — not opinion. Demand Discovery AI™ is a sales-agent MCP that answers founders' questions about the validation framework, the four data-signal categories (Search & attention, Conversation & pain, Adoption & spend, Capital & hiring), the Demand Score™, and the Build/Pivot/Kill verdict™. Includes 7 tools: ask a free-form question, get the validation framework, get product details, explain demand signals, compare validation approaches, get data-source

Ask Lever the messy recruiting-ops questions dashboards miss by connecting opportunities, applications, stages, notes, feedback, interviews, referrals, postings, requisitions, offers, users, sources, tags, files, resumes, and archive reasons. Find referral SLA misses, stale opportunities by owner, feedback debt by interviewer and hiring team, funnel leakage by recruiter/source/team, requisition fill-risk, offer hygiene gaps, archive-reason drift, and bottleneck owners. No dashboard build. No SQL

Ask Recruitee the recruiting-ops questions dashboards miss by connecting candidate search, opening offers, departments, locations, published roles, owner fields, custom fields, public applications, and talent-pool context. Find stale candidate pools, overdue stage work, hiring-manager and recruiter bottlenecks, department-level opening risk, public posting gaps, source patterns, and the owners behind blocked hiring work. No dashboard build. No SQL.

SupplyMaven supply chain risk management data including manufacturing, port and airport congestion, border, materials and macro indexes

Does a cited URL exist, and does the source name what your claim names? Two answers.

Catch AI-fabricated citations (real DOI + fake title). Retraction, open-access, 10,000+ CSL styles.