I paid for an Instagram API with 3 lines of code — no signup, no API keys

I built a pay-per-request Instagram influencer search API using the x402 protocol — HTTP 402 payments in USDC on Base. This week I tested it with AgentCash to verify the full agent-to-API payment loop. Here is the entire workflow: Step 1: Discover the API AgentCash automatically discovers any x402-compatible API: discover_api_endpoints ( " https://socialintel.dev " ) Returns all endpoints with pricing: GET /v1/search — $0.10–$0.26 depending on result count GET /v1/search/free — 3 free results for testing Step 2: Make a paid search curl "https://socialintel.dev/v1/search?query=travel&country=US&limit=5" # Returns: HTTP 402 Payment Required # After x402 payment: 5 travel influencer profiles Verified result: 5 travel photographer profiles, follower counts 78k–85k. On-chain proof: 0x294ec95cd8c76581e326a3b969f54e9f6a0561489cd7cdb2da34ff372eca6c77 Why x402 matters for AI agents Traditional APIs need API key registration, monthly subscriptions, and a human to set up billing. x402 APIs need a