Small, focused APIs, each also an MCP server. Try any of them free: every tool has free calls each day, no key or signup. Then pay per call with x402 (USDC), or buy prepaid credits by card from $5. Every API publishes llms.txt, an OpenAPI spec and an MCP endpoint.
Random UUID v4 (RFC 9562) as an HTTP API: 1-100 UUIDs per call, in uuid, URN, hex or integer form. An alternative to the X Pay UUID listing on x402 Bazaar.
GET /v1/uuid$0.0017 · 3 free/IP/dayGET /x402/uuid$0.0017 · 3 free/IP/day
Any website into clean, LLM-ready Markdown — crawl4ai-compatible, x402 per call, no keys
crawl4ai-compatible web crawler API: POST a URL, get clean LLM-ready Markdown with fit_markdown pruning. No Python, no keys, x402 per call.
POST /md$0.008 · 3 free/IP/day
Tesseract-compatible OCR over HTTP: send an image, get its text and word boxes in Tesseract's txt, TSV, hOCR and ALTO formats.
POST /v1/ocr$0.005 · 3 free/IP/day
A hosted agent-memory API shaped like mem0's REST API (an alternative to running mem0 yourself): add conversations, search, list, get and delete memories. No vector database or LLM to run. Memories are private to the secret memory_key you send; kept 365 days.
POST /v3/memories/add$0.008 · 3 free/IP/dayPOST /v3/memories/search$0.004 · 3 free/IP/dayGET /v1/memories$0.002 · 3 free/IP/dayDELETE /v1/memories$0.002 · 3 free/IP/day
One-call URL-to-PDF and full-page screenshot API with Puppeteer's page.pdf()/page.screenshot() semantics — an alternative to running puppeteer yourself or the Browserless PDF API, without any headless-browser infrastructure.
POST /v1/pdf$0.005 · 3 free/IP/dayPOST /v1/screenshot$0.005 · 3 free/IP/dayPOST /v1/snapshot$0.005 · 3 free/IP/dayPOST /v1/markdown$0.005 · 3 free/IP/dayPOST /v1/links$0.005 · 3 free/IP/day
Hosted one-shot code execution: send a snippet plus optional files, get stdout, stderr, exit code and artifacts back. Daytona execute-code compatible; no daemon to keep warm, priced per run.
POST /v1/execute-code$0.002 · 3 free/IP/dayPOST /v1/execute-command$0.002 · 3 free/IP/day
Draw detections onto an image with Roboflow supervision's own annotators, over HTTP and MCP. Send a base64 image and detections (boxes in xyxy pixels, optional class_id, confidence, label, polygon) and get back the annotated image plus per-class counts. Annotators: box, round_box, box_corner, circle, dot, ellipse, triangle, label, color, mask, polygon, halo, background_overlay, blur, pixelate, percentage_bar, chained in order. A hosted alternative to installing Python and supervision just to render detection results.
POST /v1/annotate$0.003 · 3 free/IP/day
Hosted OpenCV for finding a pattern image inside a larger image: template matching, ORB/SIFT feature matching and RANSAC homography, over HTTP and MCP. Gives automation agents pixel boxes, corners and confidence for UI elements, logos and objects in screenshots. A hosted alternative to running OpenCV (opencv/opencv) yourself.
POST /v1/template-match$0.003 · 3 free/IP/dayPOST /v1/feature-match$0.004 · 3 free/IP/dayPOST /v1/homography$0.004 · 3 free/IP/dayEvery API is an MCP server at <api url>/mcp. Add it to an MCP client (Claude Desktop, Cursor, VS Code and others) with an mcpServers entry. This example is for apidx UUID Generator; swap in any API's /mcp URL and use your prepaid credits key as the bearer token.
{
"mcpServers": {
"uuid-forge": {
"url": "https://uuid-forge.saastemly.com/mcp",
"headers": {
"Authorization": "Bearer YOUR_CREDITS_KEY"
}
}
}
}Agents that pay with x402 can call the endpoints directly; each API lists its payment requirements at /.well-known/x402. The full list is in mcp-servers.json and llms.txt.