Borrowing it
Nothing to install: this file belongs to ProjectSidewalk/SidewalkWebpage. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/ProjectSidewalk/SidewalkWebpage/develop/.github/instructions/frontend-js.instructions.mdgit clone --depth 1 https://github.com/ProjectSidewalk/SidewalkWebpageWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/projectsidewalk/sidewalkwebpage/frontend-js)<a href="https://agentmods.dev/instructions/projectsidewalk/sidewalkwebpage/frontend-js"><img src="https://agentmods.dev/badge/instructions/projectsidewalk/sidewalkwebpage/frontend-js/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/projectsidewalk/sidewalkwebpage/frontend-js"><img src="https://agentmods.dev/badge/instructions/projectsidewalk/sidewalkwebpage/frontend-js.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00432 | $0.00432 |
| Opus 5.5 | $0.00173 | $0.00173 |
| Sonnet 5.5 | $0.00086 | $0.00086 |
| Haiku 4.5 | $0.00043 | $0.00043 |
Grade A, and why
SidewalkWebpage frontend-js.instructions.md 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 23d 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.
What it actually says
Frontend JS review (ES2022 target)
- Flag
var(use const/let) and string+concatenation for HTML (use template literals). Prefer arrow functions in callbacks to keepthisbound. - The constructor-function pattern (
function Foo(){ const self=this; ...; return self }) should be aclasswith#privatefields. Flag new code using it. - No hardcoded domain values (see repo-wide rule): use
util.misc.getLabelColors(labelType)andutil.misc.getIconImagePaths(labelType); source enum members, ranges, and mappings from/v3/api/...or a view binding. Flag any{1:'good',2:'ok',3:'bad'}-style severity map, and anylabel_type_icons/*.pngpath — the frontend uses the scalable_small.svgmarker only. - No hardcoded
/assets/...URLs. Name the asset by its logical path underpublic/and resolve it withutil.assetPath('images/icons/openhand.cur'), so staged builds serve the content-fingerprinted, year-cached copy. Build the whole path before resolving a dynamic one; never concatenate onto a resolved URL or keep a base directory, which can't be fingerprinted.make lint-asset-pathsenforces this. - Tool UI scaling: in Explore, Validate, and overlays layered over them, every
fixed px dimension set from JS must be
calc(<n>px * var(--ui-scale, 1)). Flag bare px. (Fixed page chrome like the navbar is exempt.) - JSDoc on every class and non-trivial method (including
#private); use@returns(not@return) with a{Type}. - Prefer
data-i18n="ns:key"over hardcoded English strings in generated HTML.
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.
- 23d ago Changed 1d8c3e4310e8
- 1mo ago Changed · -1 lines · -15 tokens per session a97ecbd74cb5
- 1mo ago Changed · +6 lines · +104 tokens per session 03e6273efe04
- 2mo ago First seen · 22 lines · 343 tokens per session scan A 047a9128a69e
SidewalkWebpage frontend-js.instructions.md is an instructions file published in the GitHub repository ProjectSidewalk/SidewalkWebpage (111 stars, last pushed today), licensed MIT. It adds 432 tokens to every session, about $0.0017 per session on Opus 5.5. 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 2026-08-30.
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