Tool Open source
EQUAL is a Go development and testing tool that records real HTTP API traffic and turns it into a local offline sandbox, a portable JSONL cassette, and an OpenAPI 3.1 document. It runs as a local reverse proxy: an application uses its existing configurable HTTP base URL, EQUAL stores observed requests and responses with built-in redaction, and replay serves the recorded responses without contacting the provider. Replay matches methods, paths, query parameters, and request bodies, with optional strict interaction ordering; unrecorded requests fail with a 404. The tool can also verify a recorded cassette against another implementation and report differences in statuses, headers, semantic JSON, and binary bodies. It is distributed as a static binary for Linux, macOS, and Windows on amd64 and arm64, requires no runtime, account, database, or language plugin, and is licensed under MIT.
1 use taken from transcripts — each links to the moment in the video.
Records real API traffic once and lets you work against it offline from one small Go binary. It runs as a local proxy, saves requests and responses while hiding secrets, replays them, and can generate an OpenAPI spec.
1 in the library.