"Tools and methods for plotting graphs without 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.

A comprehensive suite of HTTP and API testing tools that enables AI agents to perform requests, check endpoint health, and decode JWTs. It also provides utilities for URL parsing and detailed security analysis of HTTP response headers.

MCP server enabling AI agents to use secrets (API keys, tokens) via encrypted vault, executing HTTP/shell/SSH actions server-side while never exposing secret values to the AI.

Enables Claude to manage NVIDIA API keys through an OAuth-secured MCP connector, including listing, dispensing, rotating, and revoking keys with RBAC and audit trail.

Enables users to register a single one-line secret credential (such as a personal access token) that is stored encrypted and scoped to their exact user and persona pair, then let MCP tools retrieve and use that key to call an upstream service. Key names can be listed for status checks, but the secret value itself is only decrypted inside a tool at call time.

An MCP server that exposes 43 domain tools behind 4 meta-tools, applying guardrails such as budgets, rate limits, schema validation, human-in-the-loop confirmation for mutations, PII redaction, and an append-only audit log while reducing context window usage.

Post-quantum readiness for AI coding agents: scans code for quantum-vulnerable cryptography (RSA/ECDH/ECDSA/DH) and returns NIST ML-KEM/ML-DSA/SLH-DSA (and hybrid) migration guidance, with fix verification and dependency checks. Content-based, advisory tools only; runs local (npx @quantakrypto/mcp) or as a hosted OAuth endpoint.

Enables AI agents to pay per call for live package-safety and GitHub merge-readiness trust signals via the x402 protocol.

Community MCP server for the Cymulate security validation platform. It exposes the full Cymulate REST API (337 endpoints) as 106 semantic tools for BAS, exposure validation, attack surface management, and platform administration.

Enables high-precision detection, anonymization, encryption and decryption of personally identifiable information (PII) in text using GPT-4o-based detection and advanced cryptographic methods. Supports both deterministic encryption for searchable data and format-preserving encryption for structured identifiers.

Wraps the Remnawave API to provide per-operation MCP tools with mutation safety and data redaction, enabling secure interaction with Remnawave panel.

Enables MCP clients to use paid tools for secret scanning, agent-config auditing, and OG image rendering, with payments handled over the x402 protocol on Base.

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.

Enables AI agents to access pay-per-call onchain and URL safety APIs over MCP, covering transaction explanations, token approval checks, address inspection, contract risk heuristics, URL safety, gas snapshots, ENS resolution, calldata decoding, and wallet portfolio data. Payments are handled per call in USDC on Base via x402, with no signup or API key required.

Enables autonomous Web3 security monitoring by watching honeytoken decoy private keys in the mempool to detect intrusions and trigger tripwire alerts. It also supports smart contract auditing, callgraph verification, and DeFi vulnerability triage through MCP.

Presents a plausible, tool-rich workspace surface — file reading, credential listing, command execution, database queries, and configuration retrieval — that returns only synthetic results while logging every connection, tool call, and argument received. It enables researchers to measure what MCP clients and agents actually do when handed dangerous-sounding tools, including whether they follow injected instructions or complete a retrieve-then-use credential chain.

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.

Provides 9 utility APIs for AI agents covering DNS, email, IP, QR, WHOIS, URL health, headers, text extraction, and tech detection, with x402 micropayments on Base.

Enables monitoring honeytoken decoy private keys for mempool activity, detecting and alerting on potential intrusions.

Dependency health checker for AI agent skills. Analyzes external endpoints for uptime, SSL validity, domain reputation, ownership changes, and abuse scores. Returns a 0-100 trust score per endpoint.