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

Human-in-the-loop approval: a person approves the exact AI action with a passkey, and any service can check the signed approval offline.

Perfume database API with verified notes: 1,500+ perfumes, 160+ houses, 400+ raw materials in a fragrance ingredients database. 12 tools over MCP and REST, OpenAPI spec, free and keyless, answers in 10 languages. Look up a note or raw material and get the perfumes that use it, or a perfume and get its full top, heart and base pyramid. Built by Scento.

Search 170 free home renovation tools in English and Polish (material and cost calculators, contract templates, room planners, contractor directories, DIY apps) with public user ratings. No API key needed.

Enables MCP-compatible clients to list verified free HTTP, SOCKS4, and SOCKS5 proxies, pick top-ranked ones, and summarize the current proxy snapshot through three read-only tools, without forwarding traffic or accepting arbitrary URLs.

Amazon MCP server and Amazon product data API for AI agents. Lets Claude, Cursor, ChatGPT and other MCP clients search Amazon, get real-time prices, reviews, product details, sellers, deals and best seller ranks, or look up any ASIN. One API key, 100 free requests a month.

Enables AI agents to search, filter, and monitor curated AI model API free credits and low-cost token promotions through eight tools, four resources, and three prompts — including finding deals expiring soon, checking eligibility and blocked conditions, and producing daily briefs.

Enables AI assistants to read, write, and manage Google Docs, Sheets, and Drive files through structured MCP tools using service-account authentication, without requiring an OAuth consent screen.

Search and pull 620+ React and Tailwind sections into your project over MCP.

Educational tools agent by Birkan Yavuz — an A2A + MCP server for classroom tools, with creator attribution in every result. It offers a catalog of 24 real classroom activities, including math visualizers and reading and sight-word tools.

Enables deterministic calculations for AI API and subscription costs, meeting time zones, recurring schedules, and cron next-run previews, returning normalized inputs, units, assumptions, dated sources, and links to results.

Search 47,000+ marketing agencies and get AI-matched with fitted agencies, from Pick an Agency.

Free Industry 4.0 / IIoT tools, no API key or account: lint MQTT Sparkplug B topics, check a Unified Namespace (UNS) for naming and hierarchy problems, and run an industrial AI-readiness diagnostic for manufacturing digital transformation and smart-factory projects. Works in Claude Code, Codex and any MCP client.

Eight crypto and DeFi data tools for AI agents: prices, gas, one ParaSwap route quote, GoPlus token security and top-holder samples, DefiLlama yields, Hyperliquid/dYdX funding, and observed wallet balances. Inspect prices free; pay 0.001–0.008 USDC per call on Base through x402. No API key or subscription.

Run all of WordPress + SEO, Security, WooCommerce Shop & Elementor: 10 websites in one connector. Posts, pages, media, comments and updates from Claude, ChatGPT or Cursor. Start free.

Enables validating JSON/JSONC, getting/setting values with jq-like paths, pretty-printing or minifying, validating against Ajv JSON Schema, and diffing local files or inline strings without network calls.

Enables AI assistants to query live football data, including fixtures, live scores, standings, statistics, betting odds, and full odds movement history for corner and card lines.

Stop letting your agent guess at APIs. Ask the code you actually installed. installed-api is a Claude Code plugin (an MCP server, Python standard library only) that answers "what's the signature of X?", "does Y take that argument?" and "which version do we have?" from the packages installed in this project: your .venv, your node_modules.

Real-time crypto, stock, and prediction-market data for agents — prices, indicators, funding rates, DeFi TVL, macro calendar, and an AI momentum score. Configure one Base wallet key and it just works. No signup, no dashboard, no subscription.

MCP server that enables AI agents to drive your real, logged-in browser via accessibility snapshots, with hardened credential brokering and local workflow memory.

Enables searching and browsing internet radio stations from the Radio Browser directory, retrieving live now-playing track information from station streams via ICY/Shoutcast metadata, and interacting with directory data through MCP tools without requiring API keys.

Signed, offline-verifiable authorization for API-contract changes. Before a contract change (OpenAPI, GraphQL, Protobuf, AsyncAPI, MCP manifests) merges or deploys, the agent calls preflight_change_set; the decision is deterministic, signed, and verifiable without calling CodeRifts. Three tools: preflight_change_set, verify_receipt, get_decision_details. Only a granted change can proceed.

MCP server and agent skill for the pline.ai API: scrape, crawl, batch-scrape, map, and search the web from Claude, Cursor, Codex, and any MCP client.

Enables AI agents to query multi-cloud costs, inventory, waste, and commitments across AWS, GCP, Cloudflare, and OVH through read-only MCP tools.

MCP tool server that gives any AI agent the ability to search, scrape, and analyze content across the internet.

Enables AI agents to perform common utility tasks through a streamable HTTP MCP endpoint, including JSON inspection, regex testing, cron parsing, hashing, base64 encoding/decoding, URL analysis, color conversion, text diffing, CSV parsing, JWT decode/verification, Markdown-to-HTML rendering, and UUID/token generation without API keys.

Enables users to describe a project in an MCP client and work through pre-submission grant phases, including finding fitting programs, checking eligibility and blockers, pulling precedent from past awards, shortlisting, and drafting memos, budgets, and submission checklists. Coverage is full for US grants and partial (discovery and precedent only) for Canada, with no win-odds estimates or post-award reporting.

Provides a deterministic failure-decision API for MCP clients, returning one of six actions (RETRY_NOW, WAIT, REPAIR_REQUEST, VERIFY_FIRST, ESCALATE, ABORT) based on failure context to guide safe next steps.

Verified AI free-tier limits, quota comparisons, commercial-use verdicts and zero-cost workflows. Every entry carries a human-checked verification date and is re-checked by a daily link patrol.

Provides pre-fetch routing intelligence for AI agents by recommending the cheapest reliable route (HTTP, browser, machine endpoint, or avoid) before visiting a URL.

Official MCP server for Safe Mind, the German platform for the legally required psychological risk assessment (Gefährdungsbeurteilung psychischer Belastung). 12 tools: account onboarding, departments and locations, survey drafts, and anonymity-protected aggregated analytics that never return groups below the minimum size.