Tutorials, comparisons, and guides for free developer APIs. Every post includes working code examples you can try right now.
Create and manage HD wallets across 9 blockchains. BIP39/BIP44 compliant. Balance queries, transaction sending, and cross-chain token swaps at 0.3% fee.
Search availability across 18 TLDs, check pricing, and register domains programmatically via REST API. Perfect for SaaS custom domains and AI agents.
Add automatic USDC payments to your AI agent using the x402 protocol. Pay $0.001–$0.01 per API call with no API keys, no subscriptions. Complete tutorial with working code examples.
Give your AI agent superpowers: web search, scraping, code execution, persistent memory, email, screenshots, file storage. Working examples for LangChain, CrewAI, OpenAI function calling, and Claude MCP.
Curated list of 25 free REST APIs you can use right now with no signup. Web scraping, code execution, LLM gateway, geolocation, email, PDF, screenshots, and more. Working curl examples for every API.
Search the web programmatically. Get titles, URLs, snippets. Batch multi-query search (5 at once), text extraction for LLM context. No search provider keys needed. SerpAPI alternative.
Route requests to OpenAI, Anthropic Claude, Google Gemini, Groq, Together AI, and DeepSeek through one API. OpenAI-compatible endpoint, response caching, auto retries. 24+ models, 6 providers. Bring your own keys.
Monitor website uptime, track response times, get webhook alerts on downtime. 12 endpoints: create monitors, check history, incidents, status pages, pause/resume. Intervals from 30s to 1h. No signup required.
Resize, crop, convert, optimize, blur, sharpen, and transform images via REST. Generate QR codes and placeholder images. 13 endpoints, 6 formats (JPEG, PNG, WebP, AVIF, GIF, TIFF). No signup required.
Create, share, and manage code pastes via REST. Auto language detection, collections, paste diffs, expiring links, raw content endpoints. Max 5 MB. No signup required.
Schedule recurring tasks and webhook triggers via REST. Supports cron expressions, fixed intervals, one-shot timers, pause/resume, execution history, and timezone support. No signup required.
Query DNS records (A, AAAA, MX, TXT, CNAME, NS, SOA, SRV), reverse lookups, WHOIS/RDAP data, domain availability, and propagation across 8 global resolvers. Batch resolve 50 domains. No signup.
Send plain text, HTML, or template-based transactional emails via REST. 5 built-in templates (welcome, alert, invoice, notification, password reset). Custom SMTP, delivery logs, attachments. No signup.
Upload files up to 50 MB via multipart, raw binary, or base64. Auto-expiring links (1h–7d), download limits, tags, direct share URLs, and deletion tokens. No signup. Comparison vs AWS S3, Uploadcare, file.io.
Generate PDFs from HTML, Markdown, URLs, or built-in templates (invoice, report, receipt). Chromium-powered for pixel-perfect rendering. 3 Markdown themes. No signup required.
Shorten URLs programmatically with custom slugs, click analytics, bulk shortening (50 URLs), tags, and link expiration. No signup. Comparison vs Bitly, Rebrandly, TinyURL, Short.io.
Execute code in 4 languages via API. Sandboxed environment with persistent sessions, file uploads, and a quick GET endpoint for one-liners. Build code playgrounds, interview tools, and AI agent integrations.
Look up country, city, timezone, and coordinates for any IPv4/IPv6 address. Batch lookup (100 IPs), distance calculation, EU flag for GDPR compliance. Comparison vs ipinfo.io, ip-api.com, ipstack.
Scrape websites and get clean markdown or plain text. No headless browser needed. Returns metadata, links, and images. Great for feeding content to LLMs, building search indexes, and monitoring competitors.
39+ API services for AI agents: crypto wallets, persistent memory, code execution, web scraping, screenshots, webhooks, and more. Integration examples with LangChain, CrewAI, and MCP.
Curated list of the top MCP servers: Playwright, Brave Search, AWS, Cloudflare, Notion, Firecrawl, DeFi MCP, and more. Installation configs and comparison table included.
Capture screenshots of any URL via API. 5 viewport presets, full-page mode, dark mode, CSS selector targeting, custom delays. Comparison vs ScreenshotOne, ScreenshotAPI.net, Urlbox.
Create temporary webhook URLs to capture and inspect HTTP requests. Real-time inspection of headers, body, and query parameters. Perfect for debugging integrations and testing payment webhooks.
Get real-time prices for any cryptocurrency. Supports 20+ blockchains, DEX quotes, trending tokens, historical data. Build trading bots, portfolio trackers, and price alerts.
Step-by-step guide to setting up the DeFi MCP Server in Claude Desktop and Cursor. All 12 MCP tools explained with example prompts. Also available as a REST API.
Build an automated trading bot using free crypto price, wallet, and DEX APIs. Token scanning, portfolio management, and trade execution. Python and Node.js examples.
Build a working AI research agent that fetches live data, analyzes it in a sandbox, stores findings in memory, and generates PDF reports. Under 100 lines of Python.
Give your AI agent its own crypto wallet. Check balances, track prices, get DEX quotes across 9 blockchains. LangChain integration with working Python code.
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