Customization¶

The installer is designed for forking. Three extension points cover almost every customization scenario without modifying the bootstrap or CLI dispatcher.

1. Override an existing template¶

Templates live under templates/. To override one, copy it into your fork and edit. The installer always prefers files under templates/ in its own checkout — if you fork the repo, your edits win.

# inside your fork
$EDITOR templates/pages/admin/theme.md.template
./scripts/bin/install init --profile full /tmp/test-fork

For one-off site-level overrides (without forking the theme), the installer does not overwrite existing files unless you pass --force. Edit the file in your generated site directly; future install upgrade runs preserve it (and warn if the upstream template diverged).

2. Author a custom profile¶

See profiles.md. Drop a templates/profiles/<your-slug>.yml into your fork; install list-profiles picks it up automatically.

# templates/profiles/blog-only.yml
name: blog-only
display_name: Blog Only
description: Just the blog scaffold, no docs/admin pages
legacy_flag: --minimal
recommended_for: writers who want zero ceremony

includes:
  - Gemfile
  - _config.yml
  - pages/blog.md
  - _data/navigation/main.yml

deploy_targets:
  - github-pages

ai_features:
  agent_files: [copilot]

3. Add a custom deploy target¶

Two artifacts to add:

a) The module: scripts/lib/install/deploy/<your-target>.sh implementing the four-function contract.

# scripts/lib/install/deploy/cloudflare-pages.sh
deploy_cloudflare-pages_check_prereqs() {
  command -v wrangler >/dev/null || {
    log_warning "wrangler CLI not found"; return 1
  }
}

deploy_cloudflare-pages_install() {
  local target_dir="$1" repo_root="$2"
  deploy_render "$repo_root/templates/deploy/cloudflare-pages/wrangler.toml.template" \
                "$target_dir/wrangler.toml"
  deploy_render "$repo_root/templates/deploy/cloudflare-pages/pages-deploy.yml.template" \
                "$target_dir/.github/workflows/pages-deploy.yml"
}

deploy_cloudflare-pages_verify() {
  [[ -f "$1/wrangler.toml" ]] || return 1
}

deploy_cloudflare-pages_doc_url() {
  echo "https://developers.cloudflare.com/pages/"
}

b) The templates: templates/deploy/cloudflare-pages/wrangler.toml.template and pages-deploy.yml.template. Use {{VAR}} placeholders — template.sh::render_template substitutes them. Allowed placeholders: {{SITE_NAME}}, {{GITHUB_USER}}, {{GITHUB_REPO}}, {{RUBY_VERSION}}. Add more by extending the allow-list in deploy/registry.sh::deploy_render.

c) Register it: Add the module name to DEPLOY_TARGETS= in scripts/lib/install/deploy/registry.sh.

After that:

./scripts/bin/install list-targets         # confirms registration
./scripts/bin/install deploy cloudflare-pages /tmp/test

4. Custom agent files¶

install agents copies from templates/agents/ plus the canonical guidance under .github/. To ship a different set:

Edit templates/agents/CLAUDE.md.template or aider.conf.yml.template in your fork.
For a brand-new agent type, add templates/agents/<tool>.template and extend agents.sh::agents_install with a new --<tool> flag.

5. Custom AI prompts¶

System prompts live under templates/ai/prompts/. They are plain markdown — fork and edit. install wizard --ai, install diagnose --ai, and install deploy --ai-suggest pick them up automatically.

What you should NOT customize¶

scripts/bin/install — keep this stable; it's the public CLI surface. Add subcommands by adding modules under scripts/lib/install/ and wiring them in.
Public function signatures in scripts/lib/install/*.sh — other modules (and forks) depend on them.
.zer0-installed marker file format — install upgrade parses it.

Upstreaming¶

If your customization could help others, open a PR against bamr87/zer0-mistakes. Profiles, deploy targets, and prompt improvements are especially welcome.

Last updated: 2026-04-20 — Phase 7.