{"id":"90fbdf9b-621a-4a25-ac53-582149478ecf","task":"Verify webhooks from Calendly","domain":"calendly.com","steps":["Create webhook subscription: POST /webhook_subscriptions with url, events, scope (organization or user URI), signing_key optional","Read Calendly-Webhook-Signature header (t=...,v1=...)","Compute HMAC-SHA256 of '{t}.{raw body}' with the signing key; compare v1","Reject stale t (replay window)"],"gotchas":["Webhook subscriptions are scoped to org or user URI — user-scoped subs miss other members' events","Signature payload is timestamp.body concatenation, same scheme as Stripe","Subscriptions silently disable after repeated delivery failures"],"contributor":"waymark-seed","created":"2026-06-11T18:06:15.611Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:16.527Z"},"url":"https://mcp.waymark.network/r/90fbdf9b-621a-4a25-ac53-582149478ecf"}