"OpenAI's Web Retrieval Infrastructure" matching MCP connectors:

400+ pay-per-call tools + 100 skill packs. USDC + USDG on 10 chains, or free via PoW.

CatchAll is a web search API built for comprehensive event retrieval — not ranked results, but all matching records.

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.

MCP server for GOV.UK — search, content retrieval, organisation lookup, and postcode resolution.

Official MCP server providing AI assistants with direct access to Stimulsoft Reports & Dashboards developer documentation. Enables semantic search across FAQ, Programming Manual, Server Manual, User Manual, and Server/Cloud API references across all Stimulsoft platforms (.NET, WPF, Avalonia, WEB, Blazor, Angular, React, JS, PHP, Java, Python).

Universal pay-per-call tool API for AI agents. Web search, price feeds, hive memory, LLM routing, code sandbox. Free tier (10 calls/day, no signup). x402 payments on Base + Solana.

**ColdState Knowledge Search MCP Server** https://github.com/daniel-coldstate/coldstate-mcp Semantic search over 64.6M knowledge entries — the structured alternative to web search APIs and web scraping for LLM agents. No crawling, no rate limits, sub-3s responses. Cloud-hosted at services.coldstate.ai

Give your agent web search and authoritative datasets: S&P Global, FRED, OECD, SimilarWeb & more.

Web search, page reading and structured extraction for AI agents, with strong RU coverage

Search 150k+ AI agents and MCP servers. Live liveness probes, behavioral benchmarks, x402 commerce.

Real-world data for agents: air quality, geocoding, quakes, holidays, web search

Fast, intelligent web search and web crawling. New mcp tool: Exa-code is a context tool for coding

Query the HokAI catalogue of AI tools, agents, models, companies and infrastructure services.

W3C MCP — web-standards lookup over w3c/browser-specs (GitHub, CF-reachable).

Web search API: find every relevant event across the open web, not just the top results.

Bright Data MCP — Bright Data Web Unlocker + SERP API (brightdata.com)

Freshness-aware AI retrieval with 21 MCP tools for timestamped, decay-ranked live signals.

x402-paid web search for AI agents. TESTNET (Base Sepolia). No valid result, no charge.

Pay-per-call web & EU business intelligence for AI agents (x402 USDC on Base). 11 tools.

29 pay-per-result web data tools: LinkedIn, Google Maps, SEC, real estate, jobs, leads.