July 9, 2026
Shell yeah, it’s fake bash drama
Files over tools: how we built our agent with a virtual filesystem and bash
They ditched a giant tool mess for fake files and commenters are weirdly obsessed
TLDR: Knock rebuilt its AI assistant so it works through a virtual folder system instead of a giant mess of custom controls, making it easier to manage customer messages. Commenters were fascinated by the fake bash setup, with reactions ranging from "running in the matrix" jokes to proud "we built this too" bragging.
Knock just revealed that its new AI helper for customer messaging was basically rebuilt after an early version got too bloated to handle. Instead of giving the bot a huge pile of one-off buttons for every tiny task, the team handed it something much simpler to understand: a pretend computer folder system and a bash shell, so it can "look around," edit files, and save changes back. In plain English, they stopped spoon-feeding the AI dozens of special controls and let it act more like a digital office worker rummaging through folders.
And honestly? The comments are where the real party starts. The author jumped in immediately to clarify that they didn't want to spin up a full container every time, so they run the whole thing in memory inside their Elixir setup. That triggered the most delicious kind of developer reaction: half impressed, half squinting. One commenter summed up the collective vibe with the wonderfully dramatic line that this wasn't "bash+fuse" but "running in the matrix" — basically, not a real shell, but a simulated one. Another asked the dead-serious question, "What harness are you guys running?" which reads like the tech version of asking what engine is under the hood after a street race.
The hottest take came from people saying, essentially, "same here": one commenter claimed their team also built its own custom setup and is thrilled with the speed. So the mood wasn't backlash so much as nerdy validation, with a side of meme energy. The drama here isn't scandal — it's engineers excitedly discovering they're all independently reinventing the same weird fake-computer trick, and loving it.
Key Points
- •Knock launched the Knock Agent in March 2026 to manage customer messaging resources such as workflows, templates, and audiences.
- •The company’s initial workflow-focused prototype used a tool-per-type pattern based on management API primitives, but Knock concluded that model would not scale well.
- •Knock adopted a filesystem-based design inspired by Vercel’s article on building agents with filesystems and bash.
- •In the new architecture, the agent explores account contents through a virtual filesystem, uses bash for scripting, edits files in place, and then persists those changes back to Knock.
- •Because Knock is built around Elixir, it chose to port Vercel’s TypeScript-based just-bash approach to Elixir instead of rebuilding the agent stack in TypeScript.