BasicAgent

Prompt Environment: System Prompt Sandbox (Free Download)

Free prompt environment: run a small web UI to test system prompts, view prompt traces, and save your own checkpoints.

Published: 2026-01-08 · Last updated: 2026-01-08

This is a small, practical prompt sandbox you can run on your machine (or a server) and open from any browser. It’s built for fast iteration: change the system prompt, chat, and inspect the last prompt trace so you can debug what was actually sent to the model.

Download: /downloads/prompt-environment.zip

What you get

A single-page web UI (port 5002) for testing system prompts.
Model preset selector (NVIDIA-hosted models via your own API key).
“Last prompt trace” viewer (helps you debug prompt construction).
Save/load your own checkpoints (conversation + system prompt).

What this download does not include

No preloaded checkpoints.
No proprietary prompt packs.
No proprietary prompts of any kind.

The environment is public; the prompts you create inside it are yours.

Quickstart

curl -L -o prompt-environment.zip https://basicagent.org/downloads/prompt-environment.zip
unzip prompt-environment.zip
cd prompt-environment

python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

cp .env.example .env
# edit .env and set NVIDIA_API_KEY + APP_SECRET_KEY

./run.sh

Open: http://localhost:5002

Environment variables

NVIDIA_API_KEY (required): used for model calls.
APP_SECRET_KEY (recommended): session signing key.
PORT (default 5002)
API_TOKEN (optional): enables token-based API access.
SIGNUP_TOKEN (optional): required for new registrations once at least one user exists.

Security notes

Treat anything you save as durable. Don’t put secrets in prompts or checkpoints.
If you run this on a server, restrict access (VPN / auth) and use a strong APP_SECRET_KEY.