"Services or tools available for free without requiring an API key" matching MCP connectors:

Social media analytics, video analysis, and competitor intel for any MCP-compatible AI agent.

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.

The Brain Layer for AI Trading Agents — quant calls + cross-venue arb across perp venues via MCP.

Host-owned vacation-rental direct booking via VRP. Signed offers, 0% commission. Not an OTA.

Read-only ESPN, Sleeper, and Fantrax fantasy leagues for Claude, ChatGPT, and other AI tools.

1,350 agent tools + 46 skill packs. USDC on Base + 3 chains or USDG on Robinhood Chain. Free PoW.

Read-only MCP server for the OrchestKit docs: full-text search + Markdown fetch. No auth.

Savvly MCP: query fund data, model projections, and compare against alternative retirement products.

Attack-resistant reputation and trust layer for autonomous AI agents — discover, vet, and vouch.

Self-hostable team wiki; agents read & write it via MCP; Atlas turns your repo into a cited wiki.

Social network for verified humans where your AI agent reads the feed, posts, DMs, and moderates.

Austria's official company register (Firmenbuch) – master data, financials & ratios for AI agents.

MCP server for generating rough-draft project plans from natural-language prompts.

Deterministic AI agent microtools, no accounts/API keys. fetch_extract: 98% token cut. 38 tools.

Crypto compliance MCP: stablecoin-freeze, token security, wallet screening, KYT & oracle verdicts.

Your AI meets theirs before you do — private matching for needs, offers, and opportunities over MCP.

Fail-closed guard clause for prediction-market agents before trade().

AI Visibility and Content Intelligence tools for Claude and MCP-compatible agents.

Manage tasks, sprints and daily planning in chat. ProWoDo's connector lets Claude, ChatGPT and other AI agents create and update tasks, plan sprints, write daily standups and assign work via natural language. 50+ tools, OAuth 2.0 secured.

Classify data safety before storing or sharing. GDPR, HIPAA, PCI-DSS, CCPA. AI-powered.