Sparrow field notes https://sarathsp06.github.io/sparrow/blog/ Stories and engineering notes from the people building Sparrow. en A letter that keeps its own secret https://sarathsp06.github.io/sparrow/blog/envelope-encryption/ https://sarathsp06.github.io/sparrow/blog/envelope-encryption/ Thu, 01 Oct 2026 00:00:00 GMT How Sparrow protects webhook credentials with envelope encryption. A database backup turns up somewhere it should not be, so we open it and see what a stranger would find. securityencryptionarchitecture Describe the payload, get the template https://sarathsp06.github.io/sparrow/blog/ai-template-drafting/ https://sarathsp06.github.io/sparrow/blog/ai-template-drafting/ Thu, 01 Oct 2026 00:00:00 GMT Draft a subscription's transform template from a plain-language description, verified by rendering and repaired until it works, with Anthropic, any OpenAI-compatible server, or a copy-and-paste prompt. templatesaisubscriptions Speak the receiver's language https://sarathsp06.github.io/sparrow/blog/template-transformations/ https://sarathsp06.github.io/sparrow/blog/template-transformations/ Thu, 01 Oct 2026 00:00:00 GMT Why Sparrow uses Go templates for subscription transformations instead of embedding JavaScript, and what a small, restrained language buys you on the delivery path. webhooksgoperformancesecurity Write it down once https://sarathsp06.github.io/sparrow/blog/recipes-as-config/ https://sarathsp06.github.io/sparrow/blog/recipes-as-config/ Thu, 01 Oct 2026 00:00:00 GMT How Sparrow recipes turn webhooks into integrations for Slack, PagerDuty, ClickHouse and more. The first integration is a favour; by the third, you want to write it down. recipesintegrations Keep the record close https://sarathsp06.github.io/sparrow/blog/why-sparrow/ https://sarathsp06.github.io/sparrow/blog/why-sparrow/ Wed, 30 Sep 2026 00:00:00 GMT Why Sparrow is self-hosted first. A partner's endpoint goes dark overnight, and the next morning the only thing that matters is whether you can say what they missed. architectureself-hosting Knowing when to knock again https://sarathsp06.github.io/sparrow/blog/delivery-failures/ https://sarathsp06.github.io/sparrow/blog/delivery-failures/ Thu, 24 Sep 2026 00:00:00 GMT How Sparrow classifies webhook delivery failures. A timeout, a 401 and a 503 look alike on a dashboard, but each one asks for a different response. webhooksreliability