Paid services on Base matching “developer tools”

Builder Code Validator

x402 APIs grouped into categories (crypto and on-chain, LLM and AI, web and search, media, finance, social, geo and weather, developer tools, other) with listings, origins, well-paid listings, calls and median price.

Every agent and developer hits broken or confusing JSON. This tool handles the common headaches in one place: check whether JSON is valid with the exact error location, repair near-JSON with typos, pretty-print or minify, pull values out with a path expression, diff two documents, convert to and from YAML or CSV, produce a byte-stable canonical form for hashing, validate against a schema, and repo

MCP security checks and feedback for users and developers. Choose paid access without reports, or ongoing free access within limits: POST /v1/client-token; 1 check/24h + 1 for a previous-use report. Check URL/DNS, metadata/schema/auth, OSV/CVE risk and catalog drift before connecting. Verified owners can read consented weekly reports. ALLOW/BLOCK/UNKNOWN uses caller-confirmed versions. No tool exe

Checks an x402 API origin the way x402scan, the CDP Bazaar and agents read it: fetches /openapi.json and /.well-known/x402, then calls each paid route without paying (up to 30) and decodes its 402. Reports routes that do not answer 402, missing or v1-only PAYMENT-REQUIRED headers, prices that differ from the OpenAPI document, resource URLs that differ from the route, wrong USDC EIP-712 domains, mi