Self-Healing Webhooks: Using Local LLMs to Automatically Retry and Patch Failed API Payloads at the Tunnel Edge
Webhooks keep modern systems in sync, from payment events and repository notifications to internal event buses. They also fail in ways that are tedious to debug. In local development the failure is usually not the network. Your handler rejects a payload because a field has the wrong type, a required property is missing, or the provider’s API version no longer matches what your code expects. This article describes a development-time pattern: a small proxy sits between your tunnel and your app, catches validation failures ( 400 / 422 ), asks a local language model to repair the payload, and retries once. It covers what this can and cannot fix, how it interacts with webhook signatures, and where it is the wrong tool. Facts about providers and tools were checked against their documentation in October 2026. They change, so re-check before you rely on them. 1. Why webhooks fail in local development Common failure modes API version drift. Stripe pins webhook payloads to an API versio...
