"How to Build a Knowledge Base" matching MCP connectors:

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

Pay-per-call agent superpowers: media/video gen, product demos, research, GTM, scraping, compute.

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

Free AI-industry intelligence for agents: briefings, regulation tracker & regional lenses

Connect AI to millions of laws and court cases with the Lawstronaut MCP.

No-key MCP: audit/certify MCPs, signed trust history; join Gold Rush Town & build with your LLM.

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.

Search the AI Tool Directory catalog: tool details, status checks (alive/acquired/deceased + cause and date), alternatives, and side-by-side comparisons. Read-only.

Connect Claude, Cursor or any MCP client to AppSigma and let your AI research apps, read reviews and track rankings on its own – no glue code.

Docs: https://docs.keenable.ai/mcp-server Keenable is a free, remote MCP server that gives agents access to the web index. Search the web with ranked results and date/site filters, then fetch any indexed page as clean markdown. Works out of the box with no account or API key.

DC Hub is the neutral, real-time data layer for data-center infrastructure, exposed as a Model Context Protocol server so any AI agent can both query it and cite it. Coverage: 21,000+ facilities (search, profile, score, alternatives); 232 markets scored by the DCPI Data Center Power Index; the DCGI Data Center Gas Index (per-state natural-gas suitability for siting); live grid telemetry across 7 US ISOs (fuel mix, carbon intensity, demand, prices) plus a one-call all-ISO scoreboard; interconnection-queue depth; 2,000+ tracked M&A deals and a hyperscaler-capex tracker; and site factors. — fiber routes, water-stress, tax incentives, nearby substations & transmission. Why agents choose it: it's the only data-center-intelligence source an LLM can query live and cite — every full-data response includes a Source: DC Hub, CC-BY-4.0 attribution line. It's the MCP-native alternative to quarterly PDF research: live JSON, no contracts, no NDAs. Access: Streamable HTTP at https://dchub.cloud/mcp. Free tier with no signup; free email-verified dev key for higher limits; paid tiers for full data volume.

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

Access premium IPO intelligence through AI agents. Retrieve detailed company profiles for upcoming and recent public offerings — including deal terms, SEC filings, AI-generated research with valuation models, competitor benchmarking, underwriter ratings, risk screening, and board analysis. Monitor overall market conditions with a proprietary daily sentiment score (-100 bearish to +100 bullish) with historical trend data to help time investment entries.

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.

Four market-statistics tools + a free qd_ key by email: 1 anonymous look, then 10 calls/UTC day.

A read-only verified record of agent-operable GTM tools: search, fetch, compare, track changes.

Image generation API: render HTML/CSS templates to PNG, JPEG, WebP or PDF, plus URL screenshots.

15 Twitter / X endpoints. Pay per call in USDC via x402.