gc-check-sustainability

Check Sustainability

Run a quick sustainability check on the current project. For a full 9-phase audit, use /gc-setup.

Steps

1. WSG quick scan

Review the codebase against the most impactful W3C Web Sustainability Guidelines:

• 3.2 Minified and compressed assets?
• 3.3 Unused CSS/JS removed?
• 3.5 Lazy loading for non-critical resources?
• 3.7 Appropriate caching headers?
• 3.15 HTTP/2 or HTTP/3?
• 4.3 Green hosting provider?
• 4.5 CDN or edge caching?
• 2.7 Dark mode / prefers-color-scheme support?
• 2.15 System font stack or minimal web fonts?

If a wsg-compliance.json file exists, use the wsg_compliance_score MCP tool with filePath pointing to the JSON file. The file must be a JSON array of objects with id, status (full/partial/gap/na), and category fields. Otherwise, produce a quick manual assessment.

2. Green hosting check

• Use the check_green_hosting MCP tool with domain (e.g., "example.com" — protocols and paths are stripped automatically)
• If MCP is not available: check manually at Green Web Foundation
• Look for a carbon.txt file at the domain root

3. Code-level green patterns

Pick 3-5 source files (busiest modules, largest files, entry points) and:

• Use the creedengo_check MCP tool with filePath (absolute path to source file). Supports JS/TS, PHP, Python — language is auto-detected from extension
• If MCP is not available: manually check for:
  • Unnecessary DOM manipulation in loops
  • Missing pagination on large queries
  • Synchronous blocking operations
  • Oversized images or unoptimized media
  • Unused dependencies

4. Report

## Sustainability Quick Check

### WSG Compliance
| Guideline | Status | Notes |
|-----------|--------|-------|
| 3.2 Minification | pass/fail | ... |
| ... | ... | ... |

Score: ?/9 guidelines checked

### Green Hosting
- Domain: [domain]
- Green hosted: yes/no
- carbon.txt: found/not found
- Provider: [name]

### Code Patterns
| File | Issues found | Severity |
|------|-------------|----------|
| ... | ... | high/medium/low |

### Top 5 Recommendations
1. [highest impact action]
2. ...

### Methodology and sources
- WSG standard: [W3C Web Sustainability Guidelines 1.0](https://www.w3.org/TR/web-sustainability-guidelines/)
- Green hosting check: [The Green Web Foundation API](https://www.thegreenwebfoundation.org/) — database date [date]
- Code rules: [Creedengo](https://github.com/green-code-initiative/creedengo-rules-specifications) green code rules
- carbon.txt: [carbontxt.org](https://carbontxt.org/) standard

4b. Cheap wins (optional, public sites only)

Two no-measurement checks adapted from The Website Specification that reduce agent-traffic and retry waste:

• /llms.txt + Markdown endpoints — does the site expose a curated Markdown index? Agents reading Markdown instead of rendered HTML+JS transfer a fraction of the bytes.
• Correct error status codes — do 404/500 pages return the right HTTP status (not a 200 with an error body)? A soft-404 makes crawlers retry indefinitely.

These complement the green checks above; they do not change the WSG score.

Gotchas

• Green hosting databases are incomplete: The Green Web Foundation dataset doesn't cover all hosting providers. A "not green" result may mean "not in the database" rather than "definitely not green."
• WSG compliance is self-assessed: There is no official W3C certification for WSG compliance. Any score is an estimate based on available checks, not an official rating.
• Page weight is not the only emissions driver: A lightweight page served from a high-carbon grid can emit more than a heavier page from a green-hosted, edge-cached CDN. Consider the full SWD model, not just transfer size.

Post-report verification

After presenting the sustainability check report, automatically run /gc-verify in quick mode. This triggers a Chain-of-Verification (CoVe) process: extract claims from the report, generate adversarial questions, answer each independently, and present findings under a ## Verification (CoVe) heading.

Notes

• This is a quick check, not a comprehensive audit
• For detailed WSG compliance (all 80 guidelines), use /gc-setup
• For carbon measurement, use /gc-measure-sci
• For page-level emissions, use /gc-estimate-emissions