instantcms-theme

A development guide for InstantCMS themes, which control the layout and appearance of an InstantCMS website and its templates.

In plain words
What is it for?
Use it to build or modify themes, template overrides, layouts, widget positions, frontend templates, backend content templates, and visual checks.
Why use it?
It helps make targeted theme changes while preserving framework rules, existing styling, widget placement, and upgrade safety.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/instantcms-dev/instantcms-mcp/instantcms-theme
Any agent
npx skills add instantcms-dev/instantcms-mcp --skill instantcms-theme
Clone the repo
git clone --depth 1 https://github.com/instantcms-dev/instantcms-mcp

Made for: Claude Code, Codex.

Per session 25 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 231 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00025 $0.00231
Opus 5 $0.00013 $0.00115
Sonnet 5 $0.00005 $0.00046
Haiku 4.5 $0.00003 $0.00023

Measured 2d ago against content hash f3119037756d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

instantcms-theme scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/instantcms-theme/SKILL.md · 13 lines

What it actually says

InstantCMS theme

Start with load_instantcms_project and analyze_instantcms_template; use get_template_structure for framework rules. Create themes with scaffold_complete_template and copy an exact upstream file with scaffold_template_override before making the smallest required override. Preserve the active frontend theme as the location for backend content templates; admincoreui is the backend shell.

Before delivery, reconcile PHP and YAML positions with audit_template_widget_positions, validate layouts, and run frontend plus relevant PHP quality checks. Use extracted design tokens as a migration aid, not as permission to rewrite established styling. Generate visual tests when an installed InstantCMS environment is available, then review desktop/mobile screenshots and browser errors.

For upgrades, index the exact upstream ref and compare old and new maps first. Let merge_template_overrides modify only clean cases; review every conflict and the generated patch before writing files. Finish with project audit and the relevant visual regression tests.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 13 lines · 25 tokens per session scan A f3119037756d

Subscribe to this mod's changes

instantcms-theme is a skill published in the GitHub repository instantcms-dev/instantcms-mcp (10 stars, last pushed 2d ago), licensed MIT. It adds 25 tokens to every session and 231 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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