Metamorph

Metamorph is a small client-side tool for the debugging chore where you fetch a payload, pretty-print it, decode one field, unescape another, and pretty-print again - over and over. It lets you define that sequence once as a pipeline of transformation steps, then rerun it on any input. Everything happens in the browser; no data leaves the page.

How it works

• Composable steps. You build an ordered list of processing actions - Base64 decode, JSON/YAML pretty-print, regex, escape/unescape, URL parse, zstd decompress - and the input flows through them top to bottom.
• All client-side. Every transform runs locally in the browser. Nothing is sent to a server, so it’s safe to paste sensitive payloads.
• Config in the URL. The pipeline is encoded into the URL itself, so a configured transform is just a bookmark you can save and reshare.
• Compact config via Protobuf. The step config is serialized with Protocol Buffers before being stuffed into the URL, keeping that blob small even for multi-step pipelines.

Using it

You stack steps and watch the output change as you go - the input flows down the pipeline live, so building a transform is just adding a step and seeing what falls out the bottom. The real payoff is define-once, rerun-on-anything: the moment a pipeline does what you want, its config is already in the URL, so a working transform is a bookmark. Save the “decode our log format” chain once and next week you paste a fresh payload into it instead of reconstructing six steps from memory. And because nothing leaves the browser, it’s fine to paste something sensitive - the URL carries the steps, never the data, so a saved pipeline is safe to reshare while whatever you ran through it stays yours.

Notes

Extending it is a matter of adding an ActionCode to the protobuf model, regenerating, and dropping a processor component alongside the existing ones. It’s deployed as a static site on Cloudflare Pages.