Drop in a proxy. Let it learn from real traffic. Replay it in CI — no real services, no flakiness, no fixtures to maintain.
The Problem
Every team writes the same brittle fixtures. They drift, they break, and when a new endpoint ships nobody updates them. Your CI turns red. Your sprint stops.
Hours spent crafting JSON stubs that are out of date before the PR is even merged.
Tests pass locally against stale mocks. Production fails because the real API changed three weeks ago.
Nobody mocks the edge cases. A missing 404 fixture takes down a flaky test suite at 2 am.
Calling real APIs in tests means slow, flaky pipelines that depend on third-party uptime.
How it works
Drop in a single proxy — no code changes, no SDK integrations. Your app keeps talking to the same address.
Every request and response is recorded automatically. The mock library builds itself from production-accurate data.
Flip a switch. Gostly replays your recorded traffic instantly — no network, no upstream dependencies.
When a request has no recorded match, a fine-tuned model generates a realistic response on the fly.
Why Gostly
One docker-compose file and you're running. No agents to instrument, no SDK to integrate, no YAML to wrestle.
Mocks are sourced from real traffic, not developer imagination. When the API changes, your recordings update with it.
A fine-tuned model handles edge cases you never thought to mock. No more failing tests on an unexpected 429.
Tests that called real APIs now respond in milliseconds. Pipelines that took 12 minutes finish in 90 seconds.
Response sequences let you mock multi-step workflows — create, read, update, delete — without hacking around state.
Sensitive headers are redacted before anything is recorded. You control what gets stored, full stop.
Pricing
Start for free. Upgrade when you need AI inference or team features.
Gostly records what your API actually does and plays it back — forever. Set it up in minutes, save your team days.
Get started free→