---
schema: 1
type: term
title: '**system prompt**'
description: >-
  **system prompt** — a fixed set of instructions sent to an AI model alongside
  each user prompt, telling it how a platform works and how it should behave. In
  this channel's material, Val Town's Townie combines the user's prompt with a
  large system prompt describing how Val Town works (its Deno JavaScript
  runtime, no need to start or deploy a server, which platform bugs to avoid,
  and documented features like its OpenAI integration), and sends both to Claude
  3.5 Sonnet [^ebfee90b]. [^ebfee90b]: Do 60-Minute Coding Tasks in 60
  Seconds—With AI — Ep. 41 with Steve Krouse.
canonical: 'https://liquidgold.cc/channel/everyinc/explore/term/system-prompt-8d69090a50d4'
markdown: >-
  https://liquidgold.cc/channel/everyinc/explore/term/system-prompt-8d69090a50d4.md
llms: null
parent: 'https://liquidgold.cc/channel/everyinc/llms.txt'
channel: everyinc
updated: '2026-10-23T22:12:35.346Z'
language: null
children: []
---


# \*\*system prompt\*\*

Canonical: https://liquidgold.cc/channel/everyinc/explore/term/system-prompt-8d69090a50d4

Parent: [Channel index](https://liquidgold.cc/channel/everyinc/llms.txt)

## Definition

**system prompt** — a fixed set of instructions sent to an AI model alongside each user prompt, telling it how a platform works and how it should behave. In this channel's material, Val Town's Townie combines the user's prompt with a large system prompt describing how Val Town works (its Deno JavaScript runtime, no need to start or deploy a server, which platform bugs to avoid, and documented features like its OpenAI integration), and sends both to Claude 3.5 Sonnet [^ebfee90b]. [^ebfee90b]: Do 60-Minute Coding Tasks in 60 Seconds—With AI — Ep. 41 with Steve Krouse.

In the channel's material, **system prompt** shows up in the context of Val Town's AI assistant **Townie**. Your prompt is combined with what founder Steve Krouse calls a _big ass system prompt_ explaining how Val Town works, and both go to the underlying model, **Claude 3.5 Sonnet** [^ebfee90b]. Krouse credits the system prompt as one of three reasons Townie rebuilt a full-stack podcast app from a single prompt in under a minute — a task that took roughly an hour a year earlier: - **Platform facts**: the prompt tells the model that code runs in **Deno JavaScript**, not Node or client-side JS, and that it never needs to start or deploy a server. - **Bug avoidance**: it documents which platform bugs to steer clear of. - **Documented goodies**: platform features — like the OpenAI integration used by a generated app's question button — are written into the prompt so the model can use them directly, replacing docs a human would otherwise paste in [^ebfee90b]. The system prompt is what turns raw model capability into a working product: it encodes the platform's rules and features so the model can produce correct code on the first try. It's also a maintained asset — Val Town iterates on prompting per model, and even rolled back a model update when they couldn't get its prompting right [^ebfee90b].  - A **system prompt** is fixed instructions sent alongside the user's prompt to shape the model's behavior. - Val Town's prompt teaches the model how **Val Town** works: Deno JavaScript, no server management, known bugs to avoid. - Documented platform features in the prompt let the model use them without pasted docs. - Prompting is per-model and iterated on — even rolled back when a new model couldn't be prompted correctly.  [^ebfee90b]: Do 60-Minute Coding Tasks in 60 Seconds—With AI — Ep. 41 with Steve Krouse.