"Free APIs and services without commercial fees" matching MCP servers:

Scans code for exposed secrets, API keys, tokens, and credentials across 69 patterns covering cloud services, AI platforms, payment providers, authentication services, and databases.

A thin MCP server that wraps provenance-receipts and quality-gate services as tools, enabling AI agents to certify content origin and score quality via Ed25519-signed receipts.

Pay-per-use AI security and research tools for autonomous agents on Base, enabling honeypot detection, risk assessment, wallet analysis, and yield optimization via the x402 protocol.

Enables AI agents to access DDG's payable services including checkout/payment conformance, MCP/tool security audits, agent-discovery repair, and buyer-agent smoke probes, with structured payment challenges.

Enables AI agents to inspect any public domain’s web technology stack, email deliverability and DNS health (MX, SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI), and HTTPS security posture with typed JSON scores and remediation-ready findings, plus history, bulk checks, monitoring alerts, and reverse technology lookups.

Enables named, authenticated callers to run read-only introspection of a Google Cloud project and to read and write per-tenant notes that stay isolated between callers. Every request is scope-checked against a reviewed policy, rate-limited per caller, and audited without ever logging argument values.

Enables AI agents to analyze images from a URL, local path, or Base64 string and determine whether they are AI-generated, including detection of signatures from Flux, Midjourney, DALL·E, and Stable Diffusion. Also inspects cryptographic C2PA provenance manifests, signing certificate authorities, and camera EXIF metadata without requiring API keys or accounts.

Enables AI assistants to manage multi-cloud resources (AWS, Azure, GCP) including resource operations, cost analysis, monitoring metrics, and security compliance checks through natural language commands.

Enables AI agents to score their outgoing responses against groundedness and prompt-injection risks mid-turn, returning allow, warn, or block verdicts before the response reaches the user.

Enables AI agents to securely reach enterprise tools and other agents through a governed gateway with pinned tool definitions, delegated authorization, content inspection, human approval, and signed audit trails.

Validates URLs and checks their reputation to help identify AI hallucinations and verify web page authenticity.

Stateless Streamable HTTP MCP endpoint with OAuth 2.1 authentication via Cloudflare Workers, supporting PKCE, DCR, and token introspection.

Compare service-grant changes, tool alias origins, and saved MCP tool definitions with Gooo rules. Reports preserve incomplete-capture uncertainty and source bindings. No grants are applied and no compared tools are invoked.

Enables generating secure passwords, exposing password policies, and providing reusable prompt templates for secure password creation through MCP primitives.

Implements a secure MCP server with API Key and JWT authentication, providing tools like echo, login, secure_action, and admin_action. Includes MCP Inspector integration for testing and debugging.

Enables AI assistants to search Webamon threat intelligence databases, submit URLs for scanning, retrieve scan reports, and browse phishing campaigns and infrastructure clusters using Lucene-powered queries.

Enables AI agents to discover and invoke backend tools over MCP JSON-RPC while enforcing 3-legged OAuth 2.0 identity propagation, role-based access control, and protocol transcoding to REST APIs.

Enables agents to read and report, and to carry human-authored updates into systems of record after human consent, while structurally preventing autonomous writes of commitments like owners, due dates, or statuses.

Provides trust and commerce checks for agent operators through HTTP x402 and a remote MCP endpoint, enabling clients to inspect x402 quotes, MCP handshakes, and A2A cards and to run paid verification and data tools.

Enables enterprise MCP clients and partner agents to execute tenant-isolated underwriting, claims, and compliance workflows with durable step checkpointing, evidence-grounded tool calls, and deterministic PDF citation receipts. It supports A2A task dispatch and MCP JSON-RPC operations while blocking cross-tenant access and ungrounded deliverables.

A wrapper for mcp-remote that provides secure authentication for protected MCP servers using Adobe IMS or Okta OAuth flows. It features automated token management, validation, and background refreshing for seamless access to remote resources.

Enables AI agents to discover and execute tools via a secure MCP server with JWT authentication, RBAC, rate limiting, and audit logging.

Enables automated review and analysis of network security controls (AWS Security Groups, Network ACLs) using natural language queries. Supports NSC configuration reviews, network segmentation testing, and identifying security gaps through conversational LLM interaction.

Provides governed MCP tools for querying optionally restricted Microsoft Sentinel/Log Analytics tables and optional Defender XDR hunting data, retrieving incidents and entities, and—for agent identities only—adding attributed incident comments, with Entra ID authentication, KQL validation, rate limits, and redacted audit logging.

A deployable MCP server template for Cloudflare Workers that provides Google OAuth authentication and comprehensive analytics tracking of tool usage, performance metrics, and user behavior.

Demonstrates OAuth2/OIDC authentication for MCP servers using Asgardeo, with JWT validation and a sample weather tool to showcase secured API access.

Site, email and agent safety — SPF/DKIM/DMARC, AI/SEO audit, page-change monitor, free hidden-AI scanner (4 MCP tools).

Supply chain security: free npm lockfile malware check, paid scan of packages, skills, MCP servers.

MCP server that gates API calls to AI agents using proof-of-work (free) or Lightning payment (3 sats), providing challenge, verify, and status tools for per-call authentication without accounts.

Enables agents to verify postal addresses, email addresses, and phone numbers against Melissa's Global Verification APIs before acting on the data, including batch verification and a per-session call budget to prevent runaway costs.