@fetchsandbox

Test AgentMail multi-tenant webhooks before they leak across tenants

1d ago · 4 min read · The dangerous AgentMail webhook bug starts with a response that looks completely fine. POST /v0/webhooks -> 200 OK The response body contains the webhook object. It includes your URL, event types, an

Clerk webhook replay can create duplicate users unless your sync is idempotent

2d ago · 3 min read · The login worked. The webhook worked. Then the same event arrived again. Clerk webhooks are easy to treat like a notification: user.created arrived create a local user done That works until the event

WorkOS directory sync webhooks need reconciliation after Okta group renames

6d ago · 4 min read · The bug shows up two minutes after the customer says, "we only renamed the group." In Okta, the admin changed Enterprise Admins to Platform Admins. WorkOS sent dsync.group.updated. Your webhook handle

Clerk JWT 401 on the server? Check these 3 env vars first

Jun 9 · 2 min read · A Clerk login can look fine in the browser and still fail on your server with a 401. The frontend has a user. getToken() returns something. The request includes: Authorization: Bearer <token> Then Fa

Brownfield Slack alerts: a 6-minute guided MCP run on Stripe + Resend webhooks

May 27 · 3 min read · TL;DR — I asked Cursor to add Slack alerts for failed payments in an app that already had Stripe, Clerk, and Resend. FetchSandbox MCP spent most of the ~6.5 min run reading webhook handlers, routed to