KraiNode is a browser-based API/RPC diagnostics platform used by 400+ engineers. It lets you send requests to any endpoint, inspect response latency, compare the reliability of providers side by side, and quickly spot degraded or misbehaving upstreams — turning vague "the API feels slow" reports into concrete, reproducible findings. It started in blockchain/RPC environments but the workflow applies to any HTTP/JSON-RPC API.