{
  "schema_version": "agentanalytics.task_evidence.v1",
  "title": "Transactional email webhooks in TypeScript: Resend vs Postmark vs SendGrid (2026)",
  "canonical_url": "https://agentanalytics.org/research/transactional-email-webhooks-typescript",
  "published_at": "2026-08-09T05:00:00Z",
  "source_query_run": "transactional-email-apis-2026-07-25T20-47-58-496Z",
  "source_query_outcome": "implementation",
  "observed_queries": [
    {
      "count": 8,
      "query": "transactional email webhook delivery bounce events 2026 Resend SendGrid Postmark comparison"
    },
    {
      "count": 2,
      "query": "transactional email webhook delivery bounce events 2026 Resend Postmark SendGrid comparison"
    },
    {
      "count": 1,
      "query": "Resend webhook signature verification svix raw body TypeScript 2026"
    }
  ],
  "provider_facts": [
    {
      "provider": "Resend",
      "fact": "Svix signatures over the raw request body; svix-id for duplicate handling",
      "source": "https://resend.com/docs/webhooks/verify-webhooks-requests"
    },
    {
      "provider": "Postmark",
      "fact": "No HMAC support documented; HTTPS, Basic Authentication, optional IP allowlisting, validation, and idempotency",
      "source": "https://postmarkapp.com/developer/webhooks/webhooks-overview"
    },
    {
      "provider": "SendGrid",
      "fact": "ECDSA Signed Event Webhook, OAuth 2.0, or both",
      "source": "https://www.twilio.com/docs/sendgrid/for-developers/tracking-events/getting-started-event-webhook-security-features"
    }
  ],
  "benchmark_boundaries": [
    "Recommendation and implementation are distinct outcomes.",
    "The implementation panel did not call live provider APIs.",
    "A provider receiving zero selections is not proof that it cannot perform the task.",
    "Current provider facts are sourced to first-party documentation and should be rechecked after surface changes."
  ],
  "full_report": "https://agentanalytics.org/research/best-transactional-email-apis-typescript-saas",
  "corrections": "founders@agentanalytics.org"
}