FetchSandbox

Hey bro The website icon is showing of Next.js default icon . It would be great if that shows your website's logo .

I have spent time debugging APIs where the request worked perfectly but the webhook created unexpected issues later. A tool that can consistently recreate those situations would have saved a lot of time. Nice work on tackling such a common challenge.

Love that it covers async edge cases most testing tools miss, the MCP integration with Cursor is super smooth. One thing that would make this a no-brainer for me: built-in support for replaying recorded webhook sequences against different environments, so I can validate that a staging deploy handles the exact same payload ordering as production without re-running the whole test suite.

the webhook replay feature is genuinely useful, finally a way to test retry logic without stubbing out half my codebase

the failure-library angle is interesting but the thing I'd want proven before trusting it: who keeps the simulated failure behavior itself honest against the real API over time? stripe changes retry semantics or adds a new webhook edge case, and if fetchsandbox's simulation of that api lags the real one, you get a false sense of security - green in the sandbox, still breaks in prod, just a different flavor of the same problem you're trying to solve. is that drift something you actively monitor per-API, or does it rely on someone reporting a mismatch?

We do something similar on a smaller scale in our own Stripe integration — coupon/pause mutations carry session-scoped idempotency keys so a double-click can't create two coupons, and webhook processing claims-then-deletes on failure so LS/Stripe can safely retry. The proof-gated regression capture here (reproduce → fix → rerun) is the piece we've been doing manually — would've saved some debugging early on. Following for the async/retry simulation angle, that's usually the first thing testing tools skip.

API integration testing is becoming critical as AI agents rely on more external tools. Curious if you’ve seen AI-generated requests expose edge cases that traditional integration tests usually miss?

Hey congrats! I like how the product considers several scenarios duplicate webhooks, late events, stale state, live one layer past that, where most testing tools stop at the happy path! Question - once the shared failure library flags something like "this behavior changed in a newer API version but older integrations still trip on it," how does that get surfaced to someone still running the older version? That version scoping seems like the hardest part to get right over time.

the webhook/retry/async testing angle is the part that's actually missing from most API sandbox tools, everyone nails the happy path 200 OK case but real integration bugs live in the retry logic and race conditions. does it let you simulate out-of-order webhook delivery, or just delayed/duplicate events?

Huge congrats on launching, I’m really curious about the persistent memory part If the sandbox learns that our app fails when a Clerk webhook arrives out of order qq does it automatically create a permanent regression test case for that, or how do we save it? @rnagulapalle