FetchSandbox
Live API sandboxes for AI-written integrations — webhooks, retries and failures before production
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Most API tests stop at 200 OK — but the real breakage comes after: a webhook that fires twice, a late event, a retry that corrupts state. FetchSandbox gives developers and AI coding agents runnable sandboxes for 60+ real APIs — Stripe, GitHub, Twilio, Clerk, Resend, OpenAI and more — that run the actual integration flow with requests, state changes and webhook deliveries, surfacing the lifecycle bugs mocks never show, without burning real API quota or waiting on staging environments.
It's built for the agentic era: it connects over MCP to Cursor, Claude Code, Windsurf, VS Code and Codex, so your agent can reproduce the real bug, prove the fix, and rerun in one loop. Memory works in two layers — a global per-API layer that accumulates known failure patterns (like Stripe webhook dedup pitfalls) and a scoped layer for your own code — so agents stop rediscovering known breakage from scratch.
FetchSandbox took #3 on Product Hunt on July 12, 2026 and has crossed 1,600 MCP installs. Free to start.