Self-host Cap with Docker
A lightweight, privacy-friendly proof-of-work CAPTCHA, an alternative to reCAPTCHA or hCaptcha.
This page describes the Levelrail template for Cap (Security). It deploys the services below as one Docker Compose app on your own server.
Project site: https://capjs.js.org/.Recommended memory: about 256 MiB.
Services, ports and volumes
| Service | Image | Container ports | Volumes |
|---|---|---|---|
cap | tiago2/cap:3.0.4 | 3000 | none |
valkey | valkey/valkey:9-alpine | none | cap_valkey_data -> /data |
Environment variables
| Service | Variable | Value |
|---|---|---|
cap | ADMIN_KEY | Generated at deploy |
cap | REDIS_URL | Preset in the template |
Passwords and keys marked as generated are created for you when the app is deployed and stored as secrets. Values are not shown here.
Deploy Cap with Levelrail
In the dashboard, open Apps, choose New app, then Browse templates, and select Cap. Review the Compose body and deploy.
With the CLI:
levelrail-cli templates deploy cap-captcha --name my-cap-captchaSee Service template catalog for how templates work, and Getting started if you have not installed Levelrail yet.
More Security templates
All templates are listed in the self-host gallery.