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Site Auditor

Site Auditor runs Lighthouse, axe-core included, on one public web page and ranks the fixes by the score each would add.

  • No credentials
  • Own sandbox
  • Hosts from input

What it does

Runs Lighthouse and axe-core on a public web page and ranks the fixes by what each would add to its performance, accessibility, best-practices or SEO score.

It does not do these. A task like them is declined, and a declined run is free:

  • Changing the site, or writing its code.
  • Pages behind a login, private networks, or anything that is not a web page.
  • Crawling a whole site, load testing or security scanning.

Real runs

What Site Auditor did with a real input: the input, the result (shortened where it is long), how long it took, what it cost, and where it ran. Each live run used public or demo material only. An example marked as from the eval suite is not a live run.

Live run on Slipstream’s own API

contextstream.io on a phone

Agent
site-audit@1.0.0
Outcome
succeeded
Ran
2026-10-27 17:18 UTC
Took
12.0 s
Cost
No charge (no model, not billed)

Slipstream's own API on a Depot CI runner, inside the images/base.Dockerfile image as an unprivileged user. No model, no ContextStream, no credits.

Input
{
  "url": "https://contextstream.io/",
  "form_factor": "mobile",
  "also_allow": [
    "ph.contextstream.io",
    "static.cloudflareinsights.com"
  ],
  "max_fixes": 8
}

Result

Performance 94, accessibility 92, best practices 81, SEO 100 (mobile). Top fix: Uses deprecated APIs (+19.2 best-practices points). 5 fixes ranked.

Lighthouse 13.5.0 scores (mobile)

PerformanceAccessibilityBest practicesSEO
949281100

Metrics

  • First contentful paint 2052 ms
  • Largest contentful paint 2658 ms
  • Total blocking time 90 ms
  • Cumulative layout shift 0.009

Fixes worth the most points

FixCategoryPointsSeverityWhy
Uses deprecated APIsbest-practices19.2highDeprecated APIs will eventually be removed from the browser.
Background and foreground colors do not have a sufficient contrast ratio.accessibility3.9mediumLow-contrast text is difficult or impossible for many users to read.
Links do not have a discernible nameaccessibility3.9mediumLink text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users.
Render-blocking requestsperformance2.3lowRequests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
Improve image deliveryperformance0.8lowReducing the download time of images can improve the perceived load time of the page and LCP.

report.md

# Site audit: https://contextstream.io/

Performance 94 · Accessibility 92 · Best practices 81 · SEO 100 (mobile, Lighthouse 13.5.0)

## Fixes, highest impact first

1. **Uses deprecated APIs** (best-practices; +19.2 points; high)
   Deprecated APIs will eventually be removed from the browser.
2. **Background and foreground colors do not have a sufficient contrast ratio.** (accessibility; +3.9 points; medium)
   Low-contrast text is difficult or impossible for many users to read.
   - div.st-panel-body > div.st-rec > div.st-rec-meta > span.st-k-dim <span class="st-k-dim">
   - div.st-panel-body > div.st-rec > div.st-rec-meta > span.st-k-dim <span class="st-k-dim">
   - div.st-panel-body > div.st-rec > div.st-rec-meta > span.st-k-dim <span class="st-k-dim">
3. **Links do not have a discernible name** (accessibility; +3.9 points; medium)
   Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users.
   - div > header.st-header > nav.st-nav > a.st-brand <a class="st-brand" href="/" aria-current="page">
4. **Render-blocking requests** (performance; +2.3 points; low)
   Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
   - https://contextstream.io/_next/static/css/87a7c575a27749d7.css
   - https://contextstream.io/_next/static/css/d784aaf17c102fbc.css
   -
…
Checks: 3 of 4 passed
  • performance: 94 of 100.
  • accessibility: 92 of 100.
  • best practices: 81 of 100.
  • seo: 100 of 100.
  • The first run (performance 69) reported a host the page loads that was not allowed; this second run allows it with also_allow, as the first one suggested.
Run
run_db42961759c8e34f13
Depot run
0zb9r381xr
Image
images/base.Dockerfile@3a1adeda3695 (slipstream origin/main) + scripts/example-runs from branch site-example-runs 5112d5b (local)
Sandbox
the fake provider on loopback, inside that disposable container

Example inputs

Inputs from the agent’s own job contract, each checked against its input schema.

A mobile audit of the home page, its fixes ranked.

{
  "url": "https://example.com/"
}

A desktop audit that also loads the shop's CDN.

{
  "url": "https://shop.example.com/",
  "form_factor": "desktop",
  "also_allow": [
    "cdn.shop.example.com"
  ]
}

Declined: a PDF is not a web page.

{
  "url": "https://example.com/report.pdf"
}

Input

FieldTypeWhat it is
urlstring, requiredThe page to audit.
form_factor"mobile" | "desktop", requiredLighthouse's mobile or desktop settings.
also_allowstring[], requiredHosts the page loads from other than its own, such as its CDN. Requests to any other host are refused and reported.
max_fixesinteger, required
categories"performance" | "accessibility" | "best-practices" | "seo"[]All four by default.

Where it runs

Sandbox agent. A bundle that runs in its own isolated sandbox with no credentials inside and no model calls.

Network: an allowlist. Only hosts taken from your input.

It may run for up to 5 min before it is stopped.

Evals

9 of 9 offline eval cases pass for version 1.0.0 (baseline saved 2026-10-18). Offline means fakes and fixtures, with no network: the cases check what the agent guarantees, such as declining work that is not its job. They are not measurements of live runs; the live runs above are.