HTTP API · operational

AISkills402

Buy tested SKILL.md agent skill files per file over x402 (USDC on Base), no account; plus 10 deterministic pay-per-call repair APIs.

Store of 137 tested Agent Skills (SKILL.md files) that an agent buys over x402 for cents, with no account and no API key: GET the file URL, receive 402 with the price, pay with any x402 v2 client, receive the file and a re-download token. Packs of 10-200 skills get 20-30% off. Ten deterministic pay-per-call APIs (CSV, JSONL, Markdown table and mojibake repair, cron dialect conversion, x402 offer and payment header checks, Base receipt verification, web to Markdown) at $0.003-$0.01 per call, each with a free example. Catalog: https://api.aiskills402.com/.well-known/x402 and https://api.aiskills402.com/openapi.json; MCP server: https://api.aiskills402.com/mcp; guide: https://aiskills402.com/llms.txt. Three skills are free: translate-app-text, spreadsheet-formula, mcp-tool-schema.

endpoint: https://api.aiskills402.com/v1
auth: none (x402 payment per request)
try it: tested example call
curl -i https://api.aiskills402.com/v1/skills/cold-email/file # 402 with PAYMENT-REQUIRED (x402 v2, eip155:8453, USDC); repeat with a PAYMENT-SIGNATURE header from any x402 client (e.g. @x402/fetch)
capabilities: buy-skill-file · download-skill · list-skills · get-skill-price · buy-skill-pack · repair-csv · repair-mojibake · repair-jsonl · convert-cron-dialect · check-x402-offer · verify-base-receipt · web-to-markdown
tags: agent-skills · x402 · claude-code · developer-tools · payments
pricing: Pay per use over x402: skill files up to $0.10, run APIs $0.003-$0.01 (USDC on Base); 3 skills free
i/o: application/json → application/json
docs: https://aiskills402.com/docs
machine-readable: /api/public/registry/aiskills402-api

Follow this tool

Get an alert when AISkills402 goes down, comes back, or quietly changes shape (response schema or tool list). Free for up to 3 tools. Pro: 100 tools + webhooks for your agents.

Get a key in one call

No account, no card

100 calls/day anonymous · 1,000/day with this free key · 50,000/day on Agent Pro. The key is returned instantly in the response — send it as the x-api-key header on any /api/public/* request. The key also lets you follow up to 3 tools and get an alert when one goes down or quietly changes shape. Email is optional; add yours to receive alerts, then confirm them from your inbox.

tested example call

curl -s -X POST https://agentnexus.app/api/public/keys \
  -H 'content-type: application/json' \
  -d '{"agent":"my-agent","purpose":"tool discovery","email":"you@example.com"}'

Use it from your agent

Point any MCP-capable agent (Claude, Cursor, your own) at the no-auth endpoint — it can then find AISkills402 and every other listed interface on its own:

tested example call

claude mcp add --transport http agent-nexus https://agentnexus.app/api/public/mcp

Agents can discover AISkills402 through the Agent Nexus MCP server, /llms.txt or the discovery API.