"Web search services that don't require an API key" matching MCP connectors:

Polymarket, Manifold, Metaculus compared: one fair probability per question. No API key needed.

Reference data for prediction markets: graded resolution clarity, cross-venue links, provenance.

Exit-cost estimates, depth concentration, liquidity tiers, and sealed records; no commodity futures.

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

US funding-stress warning with construction-PIT evidence limits and explicit eligibility flags.

Free real-estate underwriting, no key or account. 6 strategies, stress tests, max offer.

Agent intake desk for property renovation. Read only, CORS open, fail closed, receipts recompute.

Bank and lender monitoring with historical-evidence limits and eligibility flags beside every claim.

See what actually settles on x402: wash-adjusted volume, payTo checks. Free, no key, no signup.

Malaysian SME accounting, e-Invoice and payroll books for your AI. 41 tools — business snapshot, P&L, balance sheet, A/R and A/P aging, cash forecast, stock, tax position, document search — plus draft-only writes (invoice, quote, receipt, bill, expense, contact, bank statement import). Every write is a pending draft a human approves in Taokeh; it can never post, edit or delete. Remote Streamable HTTP at https://taokeh.my/mcp, OAuth 2.1 or a personal access token.

Reviewed competitor pricing, offer comparisons, and market-change evidence with x402 payments.

Curated, probe-verified directory of paid x402 APIs. Agents check it before spending money.

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

Research-only MCP server that turns your AI into a quant research desk: describe any strategy in plain English, get a real backtest with institutional metrics and a verifiable audit bundle. No trades and your AI never writes the code, so it can't fool the numbers.

SEC/XBRL issuer intelligence for crypto public companies via MCP, OpenAPI, x402, and MPP.

Teardrop is the native economic layer for AI agents, providing a robust suite of tools for multi-chain portfolio tracking, DeFi yield analysis, and gas estimation. It enables autonomous agents to securely find Web3 data and manage micro-payments on-chain with zero human intervention.

Deduplicated, entity-resolved funding rounds, acquisitions, and exec moves as MCP tools.

Cross-venue Polymarket+Kalshi arbitrage: resolution mismatch, void risk & settlement divergence.

Tesouro em Foco is a free remote MCP server that brings Brazilian government bond (Tesouro Direto) pricing into AI assistants such as Claude, Cursor, and any MCP-compatible client. The engine implements the Brazilian National Treasury's official pricing methodology — validated against 269,000+ real trades — and covers all retail bond types: fixed-rate (LTN, NTN-F), inflation-linked (NTN-B Principal, NTN-B), and retirement/education bonds (Renda+ and Educa+, NTN-B1).

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).