Free
Open API
$0/forever
Every endpoint, public access, fair-use rate limit.
- 364 APIs · REST + MCP
- Sub-50ms globally on Cloudflare
- No credit card, no signup
- npm + GitHub source open
424 composable building blocks on Cloudflare Workers — REST APIs, MCP endpoints for AI agents, Chrome utilities, and starter bundles. One API key. Sub-50ms globally. Pay only when you scale.
Free tier forever · No credit card · Cancel anytime on Gumroad
Plugs into Claude, GPT, Gemini, Cursor, Windsurf, and any MCP-compatible agent.
No sales call. No 14-day trial countdown. Pick a path, ship the same hour.
Open any of the 364 APIs and call it. Every endpoint accepts an empty Authorization header on the free tier — no signup required.
One Gumroad checkout, $9/month. Removes rate limits on the top 8 APIs and ships your license key by email in under 60 seconds.
Get Pro on Gumroad →Unlimited calls to Top 8 APIs, MCP config presets (Claude/Cursor/Windsurf), Pro digest newsletter, and every new API added to the catalog — automatically.
See full pricing →By tier
By category
Three tiers. No usage surprises. Pro and Lifetime ship a license key by email in under a minute via Gumroad.
Every endpoint, public access, fair-use rate limit.
Top 8 APIs unlimited. License delivered by email in 60 seconds.
Everything in Pro plus 40+ workflow templates and config presets.
Korean billing supported via Gumroad + Polar.sh. See full Pro details →
364 APIs on Cloudflare Workers. Each ships REST + MCP endpoints, an npm package, and full GitHub source.
WCAG 2.1 AA audit at the edge — URL/HTML scan, color contrast ratio, heading order, ARIA/role checks. No headless browser needed.
Persistent memory store for AI agents. CRUD operations with namespace isolation and TTL support.
Temporary key-value storage for AI agent workflows. Store intermediate results, share state between steps.
Generate changelogs from git diffs and commit messages. Keep-a-Changelog format with semantic versioning.
Compare token costs across GPT-4o, Claude 3.5, Gemini & 30+ models. Batch estimation & budget forecasting.
Automated evaluation of LLM responses — accuracy, relevance, safety scores. Benchmark models without manual review.
Unified proxy for OpenAI, Anthropic, Google APIs. Caching, rate limiting, cost tracking, and failover in one endpoint.
Content safety, PII detection, and hallucination scoring for LLM outputs. Guard your AI pipeline at the edge.
Rewrite AI-generated text to sound natural and human. Bypass AI detectors with style-aware paraphrasing.
Intelligent routing between GPT-4, Claude, Gemini based on task complexity and cost threshold. Auto-selects cheapest model that meets quality bar.
AI Output Watermark Detector API API on Cloudflare Workers.
Analyze prompts for token efficiency, clarity, and effectiveness. Returns optimized version with estimated token savings.
Real-time status, latency, and outage tracking for OpenAI, Anthropic, Google AI. Webhook alerts on incidents.
Track and predict AI provider rate limits. Get warnings before hitting caps. Optimal request scheduling.
Track AI spending across OpenAI, Anthropic, Google, Mistral & DeepSeek. Budgets, alerts, cost optimization.
ai-stale-knowledge-detector API on Cloudflare Workers.
Pre-flight token counting for GPT-4, Claude, Gemini. Estimate costs before sending requests.
api-breaking-change-detector API on Cloudflare Workers.
Track breaking changes across third-party APIs. Get alerts when endpoints change schema or behavior.
Api Composition Gateway API API on Cloudflare Workers.
Validate API responses against OpenAPI schemas. Catch contract violations before they reach production.
Estimate API hosting costs across AWS, GCP, Cloudflare, Vercel. Compare pricing for your traffic patterns.
Monitor API responses for unexpected changes. Diff snapshots, detect regressions, alert on schema drift.
Generate mock API servers from OpenAPI specs. Realistic fake data, latency simulation, error scenarios.
Benchmark API endpoint performance. Measure latency, throughput, error rates across regions.
Api Request Deduplicator API API on Cloudflare Workers.
Estimate API hosting costs across AWS, GCP, Cloudflare, Vercel. Compare pricing for your traffic patterns.
Explain code snippets in plain English. Support for 20+ languages with line-by-line annotations.
Code Pattern Risk Scanner API API on Cloudflare Workers.
AI-powered code review — security scanning, diff review, complexity analysis. Integrates with GitHub PRs.
HEX/RGB/HSL/CMYK conversion, harmonies, WCAG contrast checking, gradient generation.
HEX/RGB/HSL/CMYK conversion, harmonies, WCAG contrast checking, gradient generation.
Cron Collision Detector API API on Cloudflare Workers.
Dead man's switch for scheduled tasks. Get alerted when cron jobs miss their heartbeat window.
Human-readable explanations, next-N runs, validation, natural language to cron. 5/6-field support.
Real-time signals: SMA, RSI, MACD, Bollinger. Multi-timeframe analysis with buy/sell/hold for 100+ pairs.
FIFO/LIFO/Average cost basis. Multi-exchange, DeFi, staking. Tax brackets for US, UK, EU.
JSON/CSV/XML conversion, flatten, filter, sort, aggregate stats. Handles 10MB+ payloads.
Deadline Engine API — holiday-aware business-day math across US/UK/DE/KR/JP/IN API on Cloudflare Workers.
Scan npm, pip, and Go packages for known CVEs. SBOM generation and license compliance checks.
LCS-based text diffing, unified patch generation, and patch apply. Compare up to 2000 lines per side at edge speed.
WHOIS, DNS, SSL, reputation, and phishing detection for any domain. Comprehensive domain intelligence in one call.
8-layer validation: MX, SPF, 550+ disposable domains, typo correction. Cuts bounce rates by 90%.
Generate embeddings and semantic search in one API call. Multi-provider support with vector similarity ranking.
Env Blueprint Validator API API on Cloudflare Workers.
Names, emails, addresses, UUIDs, custom schemas. 10+ locales, batch up to 1000 records.
Feature flag and A/B testing API. LaunchDarkly alternative on Cloudflare Workers with KV-backed persistence.
102 Google Fonts metadata, 35 curated pairings with rationale, CSS generation, font stack builder, language support check.
Serverless form submission backend. Spam filtering, email notifications, webhook forwarding. No server needed.
Korean public data as clean JSON. Exchange rates, holidays, economic indicators.
GPA Calc API — Grade-Point & Scale-Conversion Engine API on Cloudflare Workers.
Extract structured JSON data from HTML pages. CSS selector-based extraction with schema mapping.
Interactive Api Playground API API on Cloudflare Workers.
Country, city, coordinates, timezone, ISP, ASN. Sub-50ms from Cloudflare edge.
Auto-infer schemas, validate, generate TypeScript, create mock data, diff versions, produce docs.
Translate JSON values while preserving keys and structure. Batch translation for i18n workflows.
Generate, validate, decode, and refresh JWT tokens. JWKS endpoint management and key rotation.
Korean address to coordinates conversion. 도로명/지번 support. Reverse geocoding. Essential for delivery and logistics apps.
Look up Korean companies by business registration number. Industry, representative, founding date, status in English.
KRW exchange rates, Bank of Korea base rate, and consumer price index. Real-time and historical data.
Korean PIPA compliance scanner. URL to risk score + violation report.
The ONLY MCP for Korean financial data. KOSPI/KOSDAQ, stocks, exchange rates, Kimchi Premium, news.
Korean government data in English: weather, exchange rates, holidays, transport, stocks.
Korean address normalization, parsing, validation, geocoding, postal code lookup. 80+ areas built-in. The ONLY Korean address API with MCP.
Validate and normalize Korean addresses via Juso.go.kr. Standardized output with postal codes and coordinates.
Validate Korean BRN (사업자등록번호) with checksum, corporate registration numbers, and phone formats. English-friendly.
SEO analysis optimized for Korean content. Keyword density, Naver/Daum ranking factors, meta tag optimization.
Official Korean public holidays, substitute holidays, and business day calculator. Updated annually from KNPS data.
Korean text processing — tokenization, morphological analysis, sentence splitting, and jamo decomposition.
Readability scoring for Korean text. Grade level, sentence complexity, vocabulary difficulty analysis.
Korean SMS/LMS/MMS template builder with character counting. 080 opt-out compliance. Carrier-ready formatting.
Track trending topics across Korean social platforms. Real-time keyword analysis and sentiment scoring.
Generate Korean-style social proof widgets. Review summaries, purchase counts, trust badges for Korean e-commerce.
Detect risky clauses in contracts and terms of service. Non-compete, liability, auto-renewal flagging.
Score LLM outputs on accuracy, relevance, coherence, and safety. Automated eval without human review.
Llm Output Quality Monitor API API on Cloudflare Workers.
50+ LLM models with real-time pricing. Compare GPT-4, Claude, Gemini, DeepSeek costs per token across providers.
llm-response-determinism-checker API on Cloudflare Workers.
Cost-optimized routing across OpenAI, Anthropic, Gemini. Pick the cheapest model that meets your quality threshold.
Llm Token Cost Calculator API API on Cloudflare Workers.
MD to HTML and back, TOC extraction, link extraction, linting. Perfect for doc pipelines.
Structure raw meeting notes into action items, decisions, and summaries. Markdown and JSON output.
Extract OpenGraph, Twitter Card, and meta tags from any URL. Preview link cards before sharing.
Multi-Webhook Verifier — One Endpoint, 12 Providers API on Cloudflare Workers.
Convert any OpenAPI spec into an MCP server. Bridge existing REST APIs into the MCP ecosystem instantly.
Generate TypeScript, Zod, or JSON Schema types from OpenAPI specs. Type-safe API clients in seconds.
Entropy, crack-time across 6 scenarios, 10K common password check. Drop-in zxcvbn alternative.
performance-regression-detector API on Cloudflare Workers.
Detect and redact PII from text — 30+ patterns including Korean-specific identifiers (주민번호, 사업자번호). GDPR/PIPA ready.
한국 PII 특화 redactor — 주민등록번호 (체크섬 검증) / 사업자등록번호 / 법인등록번호 / 010 핸드폰 / 한글 주소 / 계좌. + 카드 (Luhn) / SSN / IBAN / 이메일 / IP. 4 mask 모드 (partial/tag/hash/remove).
SVG & PNG placeholders, avatar initials, geometric patterns. Custom dimensions & colors.
Pricing Calc API — Margin, Markup & Break-Even Engine API on Cloudflare Workers.
Production Request Debugger API API on Cloudflare Workers.
Indirect prompt-injection firewall — RAG chunks, tool output, scraped pages, email. Detects override patterns, role takeover, exfil URLs, base64 payloads, unicode tag smuggle, bidi tricks. 20 deterministic signatures.
Prompt Injection Shield API API on Cloudflare Workers.
Analyze and optimize prompts for cost, latency, and quality across AI providers. Token savings estimator.
Prompt injection, jailbreak, and PII detection for LLM applications. Pattern-based analysis with severity scoring.
URLs, vCards, WiFi, email, SMS. SVG & base64 PNG. Error correction L-H. Sub-100ms on edge.
Test, match, replace, split, validate, and get plain-English regex explanations.
Request Behavioral Analyzer API on Cloudflare Workers.
Extract structured data from resumes. Skills, experience, education parsed into clean JSON.
Semantic Response Cache API API on Cloudflare Workers.
Full-page SEO audit: meta tags, heading hierarchy, links, alt text, performance. Priority-ranked fixes.
SLA & Error-Budget API — SLO to allowed downtime, burn-rate deploy gate and SLA service credits API on Cloudflare Workers.
Scan Solidity for 13 vulnerability patterns: reentrancy, overflow, access control. Fix suggestions included.
Multi-dialect SQL static analysis — linting, 14+ anti-patterns (N+1, SELECT *, ORDER BY RAND, deep OFFSET), pseudo-plan, quality score. No DB connection required.
7 valuation methods (DCF, Berkus, Scorecard, VC, comparables) in one call. Investor-ready reports.
Validate and auto-repair LLM structured outputs on the edge. JSON schema enforcement without extra LLM calls.
Detect 150+ technologies across 14 categories. CMS, frameworks, analytics, CDN, hosting, payments, chat & more from any URL.
Sentiment, Flesch-Kincaid readability, keyword extraction, 50+ language detection. No ML needed.
IP reputation, domain safety scoring, and CVE lookup. Threat intelligence feed for security automation.
400+ cities, DST-aware conversion, meeting planner for multi-timezone teams.
Allocate and track token budgets across teams, projects, and models. Prevent cost overruns with hard limits.
Shorten URLs with click tracking, referrer data, geo stats. Sub-10ms redirects via Cloudflare KV.
Shorten URLs with click tracking, referrer data, geo stats. Sub-10ms redirects via Cloudflare KV.
Scan npm/pip/go packages for CVEs. SBOM generation and license check. Shift-left security for CI/CD.
Capture, store, and replay webhook payloads. Debug third-party integrations without a server. Persistent inbox with KV storage.
Forward, transform, and retry webhooks across services. Fan-out to multiple destinations with delivery guarantees.
Webhook Reliability Suite API API on Cloudflare Workers.
Auto-registered worker — Ab Test Stats Api. Pending curation.
Auto-registered worker — Agent Cost Companion. Pending curation.
Auto-registered worker — Agent Output Shield. Pending curation.
Auto-registered worker — Ai Cost Calculator Api. Pending curation.
Auto-registered worker — Ai Disclosure Stamper. Pending curation.
Auto-registered worker — Ai Lead Scorer Api. Pending curation.
Auto-registered worker — Anthropic Cache Advisor. Pending curation.
Auto-registered worker — Api Cost Intelligence. Pending curation.
Auto-registered worker — Api Cost Optimizer. Pending curation.
Auto-registered worker — Api Pattern Analyzer. Pending curation.
Auto-registered worker — Api Quality Monitor. Pending curation.
Auto-registered worker — Api Request Inspector. Pending curation.
Auto-registered worker — Api Request Replay. Pending curation.
Auto-registered worker — Api Schema Evolution Tracker. Pending curation.
Auto-registered worker — Business Days Api. Pending curation.
Auto-registered worker — Canonical Digest Api. Pending curation.
Auto-registered worker — Color Contrast Api. Pending curation.
Auto-registered worker — Content Negotiation Api. Pending curation.
Auto-registered worker — Cost Attribution Engine. Pending curation.
Auto-registered worker — Cron Expression Analyzer. Pending curation.
Auto-registered worker — Data Privacy Scanner. Pending curation.
Auto-registered worker — Data Transform Validator. Pending curation.
Auto-registered worker — Database Query Analyzer. Pending curation.
Auto-registered worker — Db Schema Analyzer. Pending curation.
Auto-registered worker — Dependency Risk Auditor. Pending curation.
Auto-registered worker — Dependency Risk Scanner. Pending curation.
Auto-registered worker — Distributed Rate Limiter. Pending curation.
Auto-registered worker — Dynamic Pricing Optimizer. Pending curation.
Auto-registered worker — Email Domain Reputation. Pending curation.
Auto-registered worker — Email Warmup Validator. Pending curation.
Auto-registered worker — Error Blame Radar. Pending curation.
Auto-registered worker — Gh Release Monitor. Pending curation.
Auto-registered worker — Graphql N Plus One Detector. Pending curation.
Auto-registered worker — Graphql Query Analyzer. Pending curation.
Auto-registered worker — Health Metrics Api. Pending curation.
Auto-registered worker — Html To Markdown Api. Pending curation.
Auto-registered worker — Identifier Checksum Api. Pending curation.
Auto-registered worker — Investment Calc Api. Pending curation.
Auto-registered worker — Json To Typescript. Pending curation.
Auto-registered worker — Korean Sentiment Api. Pending curation.
Auto-registered worker — Lead Gen Schema Api. Pending curation.
Auto-registered worker — Llm Prompt Optimizer. Pending curation.
Auto-registered worker — Llm Provider Router. Pending curation.
Auto-registered worker — Llm Response Quality Analyzer. Pending curation.
Auto-registered worker — Llm Token Optimizer. Pending curation.
Auto-registered worker — Loan Amortization Api. Pending curation.
Auto-registered worker — Managed Cache Strategy Api. Pending curation.
Auto-registered worker — Markdown To Html Api. Pending curation.
Auto-registered worker — Mcp Uptime Monitor. Pending curation.
Auto-registered worker — Memory Decay Scorer. Pending curation.
Auto-registered worker — Money Precision Api. Pending curation.
Auto-registered worker — Phone Formatter Api. Pending curation.
Auto-registered worker — Pr Code Review Bot. Pending curation.
Auto-registered worker — Prompt Template Api. Pending curation.
Auto-registered worker — Rag Semantic Search. Pending curation.
Auto-registered worker — Request Replay Engine. Pending curation.
Auto-registered worker — Schema Flow Converter. Pending curation.
Auto-registered worker — Schema Insight Db. Pending curation.
Auto-registered worker — Schema Validator Pro. Pending curation.
Auto-registered worker — Sentiment Multilang. Pending curation.
Auto-registered worker — Smart Api Docs Generator. Pending curation.
Auto-registered worker — Smart Data Extractor. Pending curation.
Auto-registered worker — Smart Llm Cost Optimizer. Pending curation.
Auto-registered worker — Social Post Analyzer Api. Pending curation.
Auto-registered worker — Stream Cost Meter. Pending curation.
Auto-registered worker — Streaming Json Repair. Pending curation.
Auto-registered worker — String Similarity Api. Pending curation.
Auto-registered worker — Stripe Event Simulator. Pending curation.
Auto-registered worker — Stripe Payment Debugger. Pending curation.
Auto-registered worker — Subscription Cost Tracker Api. Pending curation.
Auto-registered worker — Text Readability Api. Pending curation.
Auto-registered worker — Token Security Validator. Pending curation.
Auto-registered worker — Tool Cost Profiler. Pending curation.
Auto-registered worker — Unicode Inspector Api. Pending curation.
Auto-registered worker — Video Url Parser Api. Pending curation.
Auto-registered worker — Webhook Event Transformer Api. Pending curation.
Auto-registered worker — Webhook Payload Transformer. Pending curation.
Auto-registered worker — Webhook Signature Vault. Pending curation.
Auto-registered worker — Webhook Validator Api. Pending curation.
Auto-registered worker — Nato Alphabet Api. Pending curation.
Auto-registered worker — Roman Numeral Api. Pending curation.
Every API runs on Cloudflare's 330+ edge locations. Your users get fast responses regardless of geography.
Every API ships with an MCP endpoint. Plug into Claude, GPT, Cursor, or any MCP-compatible agent with one command.
Full source on GitHub. Audit the code, fork it, self-host it. No vendor lock-in.
The only MCP provider for Korean financial data, addresses, business validation, and government data in English.
55 Chrome extensions, all v0.4.0 published — AI FinOps · Korean-market privacy & lookup · Polymarket / KR pre-market trading edge. Each ships with a real Pro license verified against Gumroad's official endpoint, a public privacy policy, and signed zip you can load right now. Chrome Web Store listings in final rollout. Pro license unlocks 30-day history sparkline + CSV export across the lineup.
Pin today's combined OpenAI + Anthropic console spend to your toolbar. Daily roll-up + Pro 30-day sparkline + CSV export. Local-first.
Catch Korean PII (phone, RRN with checksum, email) before you screen-share. Pro DOM auto-mask toggle + 30-day scan history.
Detect 10-digit 사업자등록번호 inline and validate with the official 국세청 checksum. Pro adds history sparkline + CSV export.
Stripe + Polar + Gumroad MRR consolidated in a single popup. Pro adds 30-day sparkline + per-platform breakdown + CSV.
Surface oracle settlement lag inline on polymarket.com so you spot arbitrage windows before the market resolves. Pro 24h sparkline + CSV.
AI-scored earnings sentiment overlaid on finance.naver.com for KR pre-market traders. Pro adds watchlist + 24h history + CSV.
Polymarket 포지션 실시간 watch — NAV / unrealized / 24h closes 한 화면. 봇 운영 중인 트레이더용.
Cloudflare Workers 월 사용량 + paid plan threshold 알림 ($10 default). 100+ workers 운영자용.
Gumroad seller utility — Gumroad Sales Pulse
Claude/Anthropic developer tool — Claude Prompt Vault
dev.to writer utility — Devto Mention Tracker
Hacker News reader utility — Hn Saver With Tags
MCPize utility — Mcpize Quick Call
Korean market utility — Korean News Trans Stamp
AI workflow utility — Ai Context Sweeper
Claude/Anthropic developer tool — Claude Token Bar
MRR / revenue utility — Mrr Chart Overlay
Vercel ops utility — Vercel Deploy Pulse
Lumen Chrome utility — Stripe Payout Bar
Lumen Chrome utility — Pdf Bookmark Bridge
Threads automation utility — Threads Auto Poster
Gumroad seller utility — Gumroad Receipt Bookmark
Claude/Anthropic developer tool — Claude Usage Extension
Lumen Chrome utility — Ig Content Template
Polymarket trading utility — Pm Recoup Tracker
OpenAI/ChatGPT developer tool — Chatgpt Cost Cap
Polymarket trading utility — Polymarket Volume Flash
OpenAI/ChatGPT developer tool — Openai Key Rotator
Cloudflare ops utility — Cf Error Flash
Lumen Chrome utility — Polar Sales Overlay
Lumen Chrome utility — Supabase Row Counter
Lumen Chrome utility — Rapidapi Quota Watch
Lumen Chrome utility — Fly Deploy Radar
Lumen Chrome utility — Neon Billing Pulse
Lumen Chrome utility — Railway Cost Monitor
Lumen Chrome utility — Windsurf Usage Meter
Lumen Chrome utility — Cursor Key Tracker
Lumen Chrome utility — Replicate Cost Bar
AI workflow utility — Together Ai Spend
Lumen Chrome utility — Groq Rate Limiter
Lumen Chrome utility — Huggingface Bookmark
Lumen Chrome utility — Gemini Token Meter
Lumen Chrome utility — Perplexity Saver
Lumen Chrome utility — Pinecone Usage Bar
Lumen Chrome utility — Weaviate Monitor
Lumen Chrome utility — Qdrant Cost Track
Lumen Chrome utility — Modal Com Spend
Lumen Chrome utility — Bunny Cdn Monitor
Lumen Chrome utility — Render Deploy Radar
Lumen Chrome utility — E2B Sandbox Monitor
Lumen Chrome utility — Notion Clipper Quick
Lumen Chrome utility — Slack Search Saver
Lumen Chrome utility — Linear Issue Jumper
Lumen Chrome utility — Discord Pin Saver
Lumen Chrome utility — Finops Minibar
Bundles and reports for developers who want immediate value. Lifetime licenses and monthly pro access.
Monthly Pro subscription. Unlocks @lazymac/mcp + k-mcp (unified MCP servers), 40+ pre-built n8n workflow templates, MCP config presets (Claude/Cursor/Windsurf), all future updates, priority support. Cancel anytime on Gumroad.
16 most-popular MCP server security audit with A-F letter grades, full leaderboard, copy/paste fix recipes. 10 OWASP-aligned check categories. Live data from the MCPWatch crawler — passive heuristic scan, not AST. Includes free CLI (npx mcpwatch-scanner) and free GitHub Action. Updated monthly.
Premium prompts, AI coding rules, and n8n workflow templates for builders who want usable AI systems fast.
Standalone rules pack for Cursor, Claude Code, and Copilot users who want less generic AI-generated code.