📰 Dev.to · FetchSandbox

You'd think webhook events fire in order. Paddle disagrees. Here's what happens and how to handle it.

How to prove a handler is order-safe using permutation fuzzing You're testing your Paddle webhook...

Open-source playground: a real scope-escalation flaw in an agent access-key exchange, plus a greenfield Descope OTP task. 20 minutes, no accounts, no keys.

Test Descope passwordless auth and session verification without a real Descope project, and catch the common JWT verification bug before it ships.

Unit tests returned 200. The PR merged. Then webhooks never reconciled because step two used a fake ID. We gate deploys with FetchSandbox MCP workflows in GitHu

Four ways we tried to let partners test our API — docs, UAT, IP-whitelisted staging, then production. Each one failed worse than the last.

POST /emails gives you an ID. The bug shows up later when email.delivered, email.opened, and email.bounced arrive and your app cannot reconcile them to one inte

AgentMail webhook creation can look done after a 200 OK. The real test is whether the persisted webhook is still scoped to the inboxes you sent.

Okta group renames can arrive through WorkOS directory sync as partial webhook events. If feature gates trust the payload, users split by cache state. Re-fetch

Sending an email gives you an ID. The harder part is proving your app can reconcile delivered, bounced, and opened events back to the right record.

Before wiring local envs, mock servers, and copy-pasted IDs, developers should be able to explore the real API workflow from their IDE.

Sending an email is easy. The integration pain starts when you need delivery status, webhooks, and app state you can trust.

Configure FetchSandbox MCP in Claude, Cursor, or your IDE so your agent can run guided API workflows while building integrations.

A narrow Cal.com API testing note: create, fetch, reschedule, cancel, and verify the calendar identity before users see duplicate events.

A narrow Notion API testing note: filter database rows, verify response shape, and avoid polluting a real workspace.

A narrow guide for small SaaS API teams: why docs and examples are not enough, and how to test customer and subscription workflows before production.

A narrow Polar billing integration note on why external_id matters before checkout, and how to test the customer mapping without a live API token.

Polar billing integrations start before checkout. Here's how to test customer and product state before wiring real payments.

You'd think webhook events fire in order. Paddle disagrees. Here's what happens and how to handle it.

Stripe Connect's transfer-to-payout flow is four API calls. The testing setup before you can make the first one is the hard part.

Paddle requires business verification before you can test subscription webhooks. Here's how to test the full lifecycle without waiting.

Datadog's API requires two keys just to list your monitors. Here's how to test the full flow without creating an account.

Three API calls. One template ID that has to carry through all of them. Most developers test the last call and skip the first two.

Opening a pull request is easy. The annoying part is the branch that looks mergeable until your integration hits the conflict path.