Interactive demo · real recorded GitHub traffic
Every record/replay tool returns a 404 the moment a request differs by one field from what it recorded. Gostly learns your API from your own traffic — not a guess from docs — and answers the unseen request. Redacted by default. Stateful.
Exact replay when it has seen the request — a learned, schema-correct answer, or an explicit miss, when it hasn’t.
What every competitor does
GET /repos/northwind/checkout-service/issues/4242
{
"message": "Not Found",
"documentation_url": "https://docs.github.com/rest/issues/issues#get-an-issue",
"status": "404"
}Learned from your traffic — answers the unseen shape
GET /repos/northwind/checkout-service/issues/4242
{
"url": "https://api.github.com/repos/northwind/checkout-service/issues/4242",
"repository_url": "https://api.github.com/repos/northwind/checkout-service",
"labels_url": "https://api.github.com/repos/northwind/checkout-service/issues/4242/labels{/name}",
"comments_url": "https://api.github.com/repos/northwind/checkout-service/issues/4242/comments",
"events_url": "https://api.github.com/repos/northwind/checkout-service/issues/4242/events",
"html_url": "https://github.com/northwind/checkout-service/issues/4242",Answers shown are real recorded responses, curated for the demo; the free-form box runs the live learned model (hosted for this demo). In production, matched answers are served from cache — no model in the request path. Cassette lane = exact-match, like every competitor.
─ POINT IT AT YOUR TRAFFIC
Gostly is self-hosted: single-tenant, your traffic never leaves your VPC, and in production there’s no LLM in the request path — matches are pre-generated and served from cache.
Want it pointed at your stack? Tell us where to reach you — Nick runs the demo on your APIs and answers questions directly.