Hi, I m the author. Quick tour before the comments do it for me.StuntAPI, `stunt` for CLI friends, runs local, stateful stand-ins for the public APIs your code talks to. `brew install --cask stuntapi/tap/stunt`, then `stunt demo` — you get a Stripe-style sim on a local port, and the curl it prints actually means it:create a charge, list it back (the charge is there — state persists across requests and restarts), capture it, and watch the signed webhook fire at a local sink. All synthetic, all offline, no Stripe account.Why I built it: I ve spent twenty-odd years integrating other people s APIs — commodities trading and market data in London, fintech, payments, blockchain RPC infra — and the test story never got better. Sandbox accounts, live secrets in CI, rate limits, flaky suites because the mock didn t behave like the real thing. WireMock/Prism/MSW are great at static and schema-shaped mocks; what I always wanted was a runnable stand-in — create, list, mutate, webhooks, auth expiry, cursor pagination, state machines — without writing it all myself. So: 95 adapters (Stripe, Twilio, GitHub, S3, Salesforce, ...), each one YAML + sandboxed Starlark handlers + synthetic fixtures.The part I d genuinely like holes poked in: adapters run in a Starlark VM with no host I/O or network — that s the property that makes it safe to `stunt catalog add` a stranger s adapter, the way you d install an npm package. State lives in engine primitives (SQLite collections, KV, blob store, HMAC tokens, webhook emitter with real provider signature schemes), and everything is deterministic — injectable clock, seeded RNG.Yes, this works great in tests of course.To keep the adapters honest, CI drives the real provider SDKs against them: stripe-go, aws-sdk-go-v2 (real SigV4), go-github, twilio-go, go-shopify, and the Node trio (stripe-node, octokit, twilio-node) through the actual binary.And this is just the beginning, if there s traction, we ll see more and more of these. I ll just keep adding the ones I use personally for now.That harness caught real bugs: Stripe money fields coming back as JSON strings (typed SDKs just reject the response), GitHub pagination Link headers pointing at production — octokit followed them straight to the real api.github.com.Honest limits: adapters are unofficial and fidelity-ranked, not API-complete; I d rather nail the flows real integrations actually exercise than checkbox every endpoint. Windows is currently a script install rather than the default winget source. And if you integrate an API that s missing, `stunt adapter import openapi|har|proto` scaffolds one — PRs welcome. Docs @ https://stuntapi.comWhat should adapter #96 be? I m Alessandro BTW (https://polymatto.com/about, @polyMatto on X) — engineer for two decades+, Italy to London and now raising my young family in exile, surrounded by trees and/or beach as much as possible, trading floors to web3 infra and everything in between, now spending my open-source time directing clankers in various ambitious projects adn no, this one wasn t ambitious at all, just useful and one that I am expecting to flop in here since it s literally my first post. I know, I should feel ashamed!But more is coming soon, wintty is probably going to be my next post. Stay tuned!Happy to answer anything and to intercept the, hopefully, fresh virtual tomatoes you d throw at me.Ciao!